CA1093433A - Surface alloying and heat treating processes - Google Patents
Surface alloying and heat treating processesInfo
- Publication number
- CA1093433A CA1093433A CA281,514A CA281514A CA1093433A CA 1093433 A CA1093433 A CA 1093433A CA 281514 A CA281514 A CA 281514A CA 1093433 A CA1093433 A CA 1093433A
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- CA
- Canada
- Prior art keywords
- zone
- article
- metal
- alloying
- allotropic
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Classifications
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22F—CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
- C22F3/00—Changing the physical structure of non-ferrous metals or alloys by special physical methods, e.g. treatment with neutrons
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K35/00—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting
- B23K35/22—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by the composition or nature of the material
- B23K35/24—Selection of soldering or welding materials proper
- B23K35/28—Selection of soldering or welding materials proper with the principal constituent melting at less than 950 degrees C
- B23K35/286—Al as the principal constituent
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S277/00—Seal for a joint or juncture
- Y10S277/922—Bonding or joining for manufacture of seal
Abstract
ABSTRACT OF THE DISCLOSURE
A method is disclosed for increasing physical properties of a non allotropic metal article along a beam affected zone. Non-allotropic is defined herein to include non-transformation hardenable metals having a hardness below Rc 25. A preferred method comprises passing a high energy beam, of at least 10,000 watts/cm2 measured at the interface of the beam, across a predetermined surface area at a rate to cooperate with the proportioning of the total article mass with respect to the beam affected zone mass to produce a rapid self-quenching rate and thus assure a desired precipitate and/or intermetallic compound in the resolidification zone. The high energy beam is preferably a laser generated by a device having a power level of at least 500 watt. The method may be varied in several respects (a) alloying ingredients may be previously deposited over the beam affected zone so as to be turbulently mixed with melting of the base material in said zone, (b) alloying ingredients may be constituted as a wire and fed into the high energy beam to be contemporaneously melted with the base material, (c) the alloying ingredients are selected as those having an affinity to form intermetallic compounds with the non-allotropic metal base, such as copper, manganese, chromium, zinc, cobalt, magnesium, molybdenum, titanium, vanadian, tungsten, zirconium, iron and nickel for an aluminum base and silicon as an independent wear resistance particle, and (d) the alloying ingredients are proportioned with respect to the thickness of the melted zone to render a desired alloy concentration after melting to facilitate greater hardness, greater corrosion resistance, or greater fatigue life of the affected surface region of the article.
A method is disclosed for increasing physical properties of a non allotropic metal article along a beam affected zone. Non-allotropic is defined herein to include non-transformation hardenable metals having a hardness below Rc 25. A preferred method comprises passing a high energy beam, of at least 10,000 watts/cm2 measured at the interface of the beam, across a predetermined surface area at a rate to cooperate with the proportioning of the total article mass with respect to the beam affected zone mass to produce a rapid self-quenching rate and thus assure a desired precipitate and/or intermetallic compound in the resolidification zone. The high energy beam is preferably a laser generated by a device having a power level of at least 500 watt. The method may be varied in several respects (a) alloying ingredients may be previously deposited over the beam affected zone so as to be turbulently mixed with melting of the base material in said zone, (b) alloying ingredients may be constituted as a wire and fed into the high energy beam to be contemporaneously melted with the base material, (c) the alloying ingredients are selected as those having an affinity to form intermetallic compounds with the non-allotropic metal base, such as copper, manganese, chromium, zinc, cobalt, magnesium, molybdenum, titanium, vanadian, tungsten, zirconium, iron and nickel for an aluminum base and silicon as an independent wear resistance particle, and (d) the alloying ingredients are proportioned with respect to the thickness of the melted zone to render a desired alloy concentration after melting to facilitate greater hardness, greater corrosion resistance, or greater fatigue life of the affected surface region of the article.
Description
~ 10~3'133 The pxesent ~nvention L$ directed to surface alloying.
In many industrial applications, it is desirable to produce articles having an inexpensive and lightweight material constituting the core; such materials will typically be non-allotropic metals including aluminum. ~s earlier indicated, non-allotropic ~etals shall mean herein non-transformation hardenable metals having a hardness less than Rc 25. The surface of such articles must also possess and have physical properties not provided by the core material itself. ~uch 1:0 enhanced physical properties may include high hardness, high strength, elevated temperature wear resistance, and corrosion resistance.
Some form of new surface treating technology must be generated to achieve such properties in a precisely selected surface zone without affecting the non-allotropic metal core;
it cannot be achieved reasonably economically by applying presently known surface treating technology. Known treating technology comprises: (a) saturating the surface zone, as bv carburizing or nitriding, (b) transforming the surface zone ;
solidification phase to one which is harder, (c) attaching a coating, or ~d) alloying or heat treating the entire article.
Nitriding and car~urizing are employed with success for iron-base substrates, but are not successful with non-ferrous materials.
Transformation hardening is ~uite successful with iron-base substrates, but it is not successful with aluminum and many other non-allotropic materials. Attached coatings are expensive and may lack permanence. ~reating the entire article is wasteful of energy, is low in productivity and fails to achieve differential characteristics in the core and surface zone.
For example, with an aluminum article and the like, the prior ~ - 2 -~B
3~33 1 art has principally employed precipitation hardening through-
In many industrial applications, it is desirable to produce articles having an inexpensive and lightweight material constituting the core; such materials will typically be non-allotropic metals including aluminum. ~s earlier indicated, non-allotropic ~etals shall mean herein non-transformation hardenable metals having a hardness less than Rc 25. The surface of such articles must also possess and have physical properties not provided by the core material itself. ~uch 1:0 enhanced physical properties may include high hardness, high strength, elevated temperature wear resistance, and corrosion resistance.
Some form of new surface treating technology must be generated to achieve such properties in a precisely selected surface zone without affecting the non-allotropic metal core;
it cannot be achieved reasonably economically by applying presently known surface treating technology. Known treating technology comprises: (a) saturating the surface zone, as bv carburizing or nitriding, (b) transforming the surface zone ;
solidification phase to one which is harder, (c) attaching a coating, or ~d) alloying or heat treating the entire article.
Nitriding and car~urizing are employed with success for iron-base substrates, but are not successful with non-ferrous materials.
Transformation hardening is ~uite successful with iron-base substrates, but it is not successful with aluminum and many other non-allotropic materials. Attached coatings are expensive and may lack permanence. ~reating the entire article is wasteful of energy, is low in productivity and fails to achieve differential characteristics in the core and surface zone.
For example, with an aluminum article and the like, the prior ~ - 2 -~B
3~33 1 art has principally employed precipitation hardening through-
2 out the entire article. This method is unsatisfactory for a
3 variety of reasons including high cost, distortion, and low
4 productivity. Little or no work has been performed with respect to surface region treatments of aluminum and no work has been 6 performed with respect to utilizing a highly concentrated 7 energy beam as one of the factors in such surface treatment 8 technology.
9 EIigh intensity energy heat sources have been employed for purposes of welding, cutting and drilling, and in certain 11 limited modes for the purpose of surface hardening of ferrous-12 based materials. The high energy beam can be employed to melt 13 a very shallow surface region of an iron based article with 14 the result that the melted material can be transformed to a harder phase upon removal of the energy beam, allowing the 1~ article to perfor~ as a self-quenching medium. However, the 17 technique of using a high energy beam for surface hardening 18 ferrous-based material is totally different than its use when 19 applied to non-ferrous and particularly non-allotropic materials.
Little or no thought has been given to the concept of 21 controlling the introduction of alloying ingredients to con-22 trolled depths and proportions within a non-allotropic metal 23 base, such as aluminum,by the use of a high energy beam. The 24 lack of investigation may be attributed to the prevailing thought that the usefulness of such a beam, when applied to 26 aluminum, would be limited because (a) melting typically does 27 not lead to a hardened transformed phase within such material, 2~ (b) past experience with furnace heat treatment indicated 29 limited hardness levels to which many non-allotropic metals could be hardened, (c) the lack of commercial need to -~
1 investigate how to deep harden localized zones with little 2 distortion, and (d) the availability of alternate hardening 3 techniques for co~mercial needs which usually were shallow 4 non-severe wear surfaces, one technique being plasma spraying S which did not distort the substrate and was very flexible in 6 use. Thus, utility of a highly concentrated energy beam 7 had not been envisioned in applications involving aluminum 8 and the like.
9 Particularly with respect to aluminum, one or more of the following disadvantages may occur with present technology:
11 ~a) the article may be highly distorted as a result of the 12 hardening treatment, (b) the surface contour of the part to be 13 treated may be irregular and therefore is not susceptible to 14 uniform treatment or the article may have different sections and the different sections respond differently to the 16 hardening treatment causing non-uniformity, (c) the cost of 17 hardening an aluminum article may be relatively high due to 18 the requirement for expensive equipment or manpower, (d) the 19 method of heat treatment is unable to achieve a shallow uniform case depth with accuracy, (e) the method of treatment is 21 unable to achieve selective precision patterns of case 22 hardening over a given surface, (f) the prior art method is 23 unable to economically harden a small area of a large sized 24 article,~g) the prior art method is unable to harden small areas which are difficult to reach within a complex part, 26 (h) the prior art method is unable to be used without potential 27 damage of adjacent parts, (i) quenching becomes difficult 28 at best with certain of the prior art methods, and (j) the 29 prior art methods do not lend themselves to extremely high volume and fast rates of production. Accordingly, there is a 31 need for a method of surface treating aluminum articles, and the - . .
1093~133 like, which overcomes the above problems and in additiop improves the surface treating technology for non-allotropic materials to facilitate achieving all desirable physical properties with adequate control.
In accordance with the present invention, there is provided a method of treating a selected exposed region of a non-allotropic metal article for enhancing the physical properties of the region, comprising: (a) selecting the non-allotropic metal for the article having a thermal conductivity of at least 0.25 Cal./cm2/cm/sec~/C; (b) directing a high energy beam at an exposed region of the article to heat the article at a first zone and to melt the article at a second zone within the first zone to a predetermined depth, the beam providing an energy level at the interface with the article of at least 10,000 watts/
cm2; ~c) controlling the area of the beam interface, beam energy level, and rate of displacement of the beam along the article to restrict the first zone to a predetermined volume and ensure a predetermined fast heat-up rate of the first zone; and (d) proportioning the mass of the article to the volume of the first zone to provide a fast self-quenching cooling rate of the first zone upon removal of the influence of the beam therefrom whereby a fine grain structure and fine particles are promoted in at least the second zone.
The present invention overcomes the problems of the prior art by permitting treatment of a precisely selected exposed generally small zone of a non-allotropic metal article to achieve physical properties in that zone here-tofore unattainable. This treatment is achieved withoutdetrimentally affecting the remainder of the article.
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~0~3433 The invention is described further, by way of illustra-tion, with reference to the accompanying drawings, in which:
` Figure 1 is a schematic sectional illustration of one early step in practicing a preferred method mode of the :
present invention; the method mode involves alloying a case onto a metal substrate;
Figure 2 is a schematic sectional illustration of a subsequent step for the method mode of Figure 1, particularly involving the melting of both an alloy layer and a subjacent zone of the base metal;
Figure 3 is a schematic sectional illustration of the resulting product from practicing the steps of Figures 1 and 2, the product having been subjected to a single pass of the melting apparatus;
Figure 4 is a sectional view taken substantially along line 4-4 of Figure 3 illustrating the depth and con-tinuity of the single pass;
Figure 5 is a sectional view similar to Figure 3 but showing the result of a multiple overlapping pass of said 2~ melting apparatus;
Figure 6 is a scnematic sectional view, similar to that of Figure 2, showing an alternative mode of carrying out the first and second steps simultaneously; ~ .,.
~Figure 7 is a schematic sectional view of another process mode of this invention directed to heat treatment with no surface alloying;
Figure 8 is an enlarged schematic view of a portion of the workpiece operated upon by the method of Figure 7 showing the flow of energy input and energy dissipation;
Figures 9-11 scnematically depict different laser generating apparatus useful with this invention;
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iO93433 Figure 12 is a schematic view of a laser concen-trating apparatus for directing the beam at an article to be heated;
Figure 13 is a schematic illustration of one type of plasma powder coating apparatus that may be employed in connection with the method of Figures 1-3; and Figure 14 is a schemati~c perspective view of one type of electron beam apparatus that may be employed in practicing the invention.
The general concept of this invention is to obtain enhanced physical properties in a treated zone along the outer region of an article constit,uted of a non-allotropic metal (of sufficiently high thermal conductivity) without detri-mentally affecting the remainder of the article. The treated zone is typically arranged to be extremely small in comparison to the mass of the article for cost-saving benefits. The method comprises essentially heating and cooling. Heating consists of concentrating a high energy beam and directing such beam toward a delimited zone of the surface of the article at predetermined scan rate and energy level measured at the article interface so as to melt the metal in said zone at a sufficiently fast rate thereby isolating the remainder of the article from the heat up effect. Cooling consists of removing the high energy beam from said zone while proportioning the mass of qaid article with respect to the beam affected zone to provide a self-quenching cooling rate which insures a fine grained structure and a supersaturated solid solution. The supersaturated solution can be promoted by either diffusing independent alloying ingredients into said zone for a ., s .
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1093a~33 1 controlled dilution of the metal or by selecting an alloyed 2 base metal having a minimum level of inherent alloying 3 ingredients for supersaturation.
4 The most notable advantage achieved by practicing such method is the capability of deploying a relativelv 6 economical light substrate material, such as aluminum, and 7 the capability of restricting physical property enhancement 8 by isolating use of expensive materials to small selected 9 surface zones, therçby producing an excellent cost/performance ratio.
11 Surfa~e AlloYing 12 One of the important method modes of employing the 13 general concept provides an alloyed surface zone on the article.
14 Surface alloying is achieved by rapidly melting the selected outer zone of the article as well as an alloying agent 16 deposited previously or simultaneously into said zone. The 17 alloying agent is turbulized into the melted base metal by 18 thermal activity resulting from the action of the beam.
19 Upon quick removal of the high energy beam, a self-quenching operation ensues creating a fine grained solid solution alloy 21 with distribution of intermetallic compounds. The creation of 22 such homogeneous surface alloy region is new because at least 23 so~e investigators thought that such high thermal conductivity 24 non-allotropic metals would lose strength as a result of high energy beam exposure. And yet some others may have thought 26 that the beam affected zone would not be limited adequately to 27 permit self-quenching. It was found that the beam affected 28 zone can be most accurately limited, isolated and controlled 29 without sacrifice of needed heat up rate and self-quench rate.
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: :` 1093433 1 Turning more specifically to a detailed preferred 2 mode of carrying out surface alloying, reference is made to 3 Figures 1-6, 4 (1) An initial preparatory step of the process is to select a base material which responds to rapid heating by 6 a high energy beam, is easily melted, and will satisfactorily 7 thermally conduct heat during cooling for self-quenching.
8 Although a wide variety of metal materials can be employed, 9 the mode herein is preferably carried out with a base metal consisting essentially of an aluminum alloy. The base material 11 should have a thermal conductivity of at least .25 Cal./cm7/cm/
12 sec./C. Other non-allotropic metals as defined herein and 13 which have a sufficient thermal conductivity comprise:
14 magnesium, copper, zinc and titanium.
(2) The preferred base metal is surface alloyed by 16 the selection and use of alloy ingredients which have an 17 affinity for forming solid so}ution and intermetallic compounds 18 with the base metal. For aluminum or an aluminum alloy, the 19 ingredient can be selected from the group consisting of:
copper, nickel, tungsten, molybdenum, zirconium, vanadium, 21 magnesium, zinc, chromium cobalt, manganese and titanium.
22 Two or more of such ingredients may be added together. Copper 23 is one of the most effective alloying ingredients for 24 hardening aluminum alloys. Nickel facilitates resisting softening of the aluminum at elevated temperatures in the alloyed 26 condition. Silicon, although not forming an intermetallic 27 compound, is useful in an aluminum alloy to produce a low 28 silicon core with wear resistant high silicon surface having 29 independent wear particles. Graphite, although not forming an intermetallic compound, is useful as a high temperature solid ` ~0~343~
1 lubricant in the alloyed surface area. Alloy ingredients 2 for magnesium may include zinc, rare earth, zirconium, 3 manganese and aluminum. Alloy ingredients for copper may 4 include; lead, zinc, aluminum, tin, iron, nickel, silicon, manganese, beryllium, zirconium and chromium.
6 (3) The next step is to attach, deposit or subject 7 alloy ingredients to the beam adjacent the selected zone of 8 the base metal. One way this is accomplished is by depositing 9 an alloy layer 10 on the base metal 11 by a suitable mechanism 12 ~see Figure 10), which here includes plasma stream spraying 11 of powdered alloy metal. A preferable mode is to employ a 12 wire comprised of the alloying ingredients and feed such wire 13 into the beam (see Figure 6). vet another way is mix resin with 14 the powdered ingredients and deposit such mixture in tne path of the beam. Painting may also be employed, as long as the 16 ingredients are attached in a manner to be influenced by the 17 beam. The alloying ingredients, to be sprayed by the plasma 18 technique, can be an admixture of metal powders or can be l9 applied in independent layers. The admixed powders typically will be subjected to a very high temperature and subjected to 21 a jet velocity, however both conditions not being critical to 22 this invention.
23 The depth of the alloy layer should be controlled to 24 achieve a predetermined alloy concentration of the melted zone of the base metal. The alloying ingredients (whether added 26 or inherent in the base metal alloy) should enrich the base 27 metal melted zone to at least form a saturated solid solution 28 upon remelt. r.enerally, surface alloying will be directed pre-29 dominantly at enhancing one of three of physical characteristics (wear, fatigue life, or corrosion resistance) depending on the ,~
1(~93433 1 application and use of the treated article. To provide optimum 2 wear resistance in the treated zone of the article, the alloy 3 ingredients should be added to the melted base metal in 4 said zone in a weight ratio of 1:1 to 1:20. This may be roughly estimated by applying an alloy coating thickness which 6 is equal to or as little as 1/~ the (depth) thickness of the 7 melted base metal. This ran~e of ratios insures the generation 8 of intermetallic compounds in the melted zone upon solidifi-9 cation, which compounds constitute the primary mechanism of this invention to harden non-allotropic ~ase metals via a high 11 energy beam remelt.
12 To provide optimum fatigue life in the selected 13 surface treated zone, the ratio should range from 1:10 to 1:20 14 to provide a lean alloy dilution content and insure the avoidance of intermetallic compounds while promoting hardening 16 by precipitation or age hardening.
17 To provide an improvement in corrosion resistance 18 in the selected surface treated zone, the ratio should be no 19 less than 2:1. It may be preferable to use substantially pure aluminum for the alloying ingredient when the base metal 21 is an aluminum alloy, such as 390 or 355. ~urer aluminum has 22 a greater resistance to corrosion than said aluminum alloys.
23 A typical apparatus for carrying out the plasma 24 deposition is shown in Figure 10. The arrangement employs a plasma gun 15 containing a gas arc chamber 16 having an exit 26 throat which has a straight bore section 17 and a diverging 27 section 18. The gas supply 31 is introduced at the left han,~
28 portion of the gas chamber 16 and an arc is created acrOss the 29 chamber by virtue of an arc power supply 19. The metallic and refractory powders are introduced to the gun from a powder . .. . . . - : .
1 feeder 20 and carried to a preheating tube 21 which is 2 powered by a powder preheat supply 22; the powder is then 3 conveyed to a precise location in the exit throat by way of 4 a passage 23 which is slightly angled (at 24 with reference to a centerline 25 o~ the passage) and enters the exit 6 throat precisely at the juncture of the straight bore section 7 and the diverging section. The stream 13 from the plasma 8 gun is directed at the target article 26 to be coated. The 9 article to be coated is carried by movable support 27 so as to allow for the deposition of the powders across a wide 11 selected area or pattern. The workpiece or article 26 is 12 maintained at a specific electrical potential by way of a 13 transferred arc power supply 28 so as to receive plasma spray 14 particles. The entire workpiece, as well as plasma jet, is enclosed in a chamber 29 evacuated by a vacuum pump 30.
16 (4) As shown in Figure 2, the next step is to melt 17 by generating, directing and moving a high energy beam. A
18 high energy beam is defined herein to mean a column of radiant 19 energy (regardless of source) having an average power density in excess of 10,000 W/cm2 at the interface with the metal to 21 be treated. This step involves generation of a high energy 22 beam 32 of sufficient power, directing the beam at a selected 23 exposed zone 33 of the article and moving the high energy beam 24 32 along a predetermined path and at a specific rate so as to not only melt the selected zone of contact between the beam and 26 alloy layer 10 but also to melt a predetermined portion 34 of 27 the subjacent portion of the base metal 11. The beam will affect 28 two zones, first one which is heat influenced without melting 29 and a second zone within the first which is melted. Laser rays initially are slightly retarded by reflectivity from entering 11~93~33 1 a bare aluminum surface; this retardation is lessened by 2 (a) formation of a melted cavity when heat breaks down the 3 surface thereby permitting concentration of the rays and 4 (b) by the application of a powder alloy coating. Laser rays enter the article at the interface with high energy, but 6 with a defocused beam at least some of that intensity is lost ~y 7 reflectivity, diffusivity and refraction within the article.
8 However, this favors control of a shallow beam influenced 9 zone.
The heat-up rate of the base metal must be relatively 11 rapid so that ta) turbulence is created within the molten spot 12 pool and (b) removal of the high energy beam facilitates 13 rapid quenching. The absorptive characteristic of the base 14 metal must be controlled to assist entering of the beam rays into the base metal and thereby promote a fast heat-up rate.
16 This necessitates use of a laser beam or an electron beam.
17 It has been found by experimental procedure that ~o achieve 18 melting of the deposited alloy layer 10 (consisting of 19 silicon, copper, nickel and carbon) having a thickness of .006" (35) and to melt the subjacent base metal 11 to a depth 21 of .~25" (36), the energy imparted to the article at its 22 surface 37 must be about 70,000 watts/cm2 with a beam spot 23 diameter at the interface of .08". This can be obtained by 24 use of a laser beam generated by an apparatus 38 (disclosed in any of Figures 10-13). The definition of a proper high 26 energy laser beam for carrying out surface alloying is critical.
27 The apparatus for generating the beam must have a power rating 28 of at least 1-6 KW to achieve rapid heating and melting with 29 a commercial scan rate of .005 in.2/sec. At power levels lower than 1 KW, the beam speed can operably be as low as ; ' ' ~' ', ' ,.;~
1 .01"/minute, but this speed is commercially impractical. The 2 beam 32 should be focused to a point 40 located a distance 41 3 away from the plane of the outer surface 37 of the article 4 (either above or below); thus, the beam is defocused with respect to the interface with the outer surface of the article 6 and has a diameter 39 at said interface which may vary 7 practically between .01-.5" in diameter.
8 It is important to control interplay of the power g level of the high energy beam, the scan speed or relative vement of the beam across the surface 37 of the article, 11 and the spot size of the beam at the interface. Moreover, 12 n controlling" used hereinafter means correlating the beam 13 interface area, scan speed, and beam energy level to achieve 14 a desired melt rate and cooling rate for the beam affected zone. The energy level at the interface should be at least 16 10,000 watts/cm2; the spot size at the interface can vary 17 from .0008 in.2 to .0~ in.2 or more. The linear speed should 18 be in the range of l~-100"/minute. Proper control of these 19 parameters results in successful temperature distribution in the base metal and successful laser surface alloying.
21 The resulting alloyed case depth 42 from a single 22 pass is basically proportional to the energy application level 23 used at a given scan rate. The exact values of the power 24 level as related to the scan rate for particular surface alloying material or application will depend upon the alloy 26 coating, the base metal, and the alloyed case depth desired.
27 l'he resulting depth 42 of the alloyed case or beam affected zone 28 is shown in Figure 3. The zone for a single pass is represented 29 in cross-section by a semi-spnerical filled groove 43 having a solid solution of alloyed metal containing intermetallic "
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~093433 l compounds. You will note the top surface 44 of the resulting 2 alloyed zone is higher than the original surface of the 3 article.
4 Figure 4 illustrates the contour of the single pass S along its length. ~ complete surface of the article may be 6 provided with an alloyed case by (1) establishing multiple 7 passes of a defocused beam and (2) overlapping the zone of 8 influence of each pass so that the beam affected zone 45 will 9 appear as a number of overlapping ribs 46-47 as shown in Figure 5. The spacing and degree of overlapping of the ribs ll can be varied to establish a minimum zone depth 48. It is 12 quite possible that the passes may be separated by a wide 13 dimension so th~t only a pattern of alloyed ribbons or lands 14 may appear on the article, such lands of alloy may provide the necessary wear resistance for the entire surface. In 16 addition, the beam affected zone may be subject to a focused 17 beam (focused at the interface) and pulsated to keep the 18 energy level commensurate with melting.
l9 The preferred apparatus for generating a laser beam is shown in Figure lO and comprises a closed CO2 gas flow circuit 21 61, the gas being moved rapidly by a blower 62 and heat removal 22 by an exchanger 63. The laser discharge takes place axially 23 along the flow path between electrodes 64 and 65. The laser 24 beam discharge is trained in said axial flow direction by totally transmitting mirror 66 and emitted from the laser 26 generator housing through partially transmitting mirror 67.
27 In Figure ll, there is shown an apparatus for 28 generating a laser beam from gas with a flow 68 transverse to 29 the electrical discharge between electrodes 69 and 70. ~irror 71 is partially transmitting.
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10~3433 1 In Figure 12, there is shown an apparatus for 2 generating a laser by an electron beam 72; sustainer electrodes 3 73 and 74 are spaced apart in a high vacuum; the electron 4 emitter 75 sends electrons through membrane 76 to the S electrodes. ~irrors 77 and 78 cooperate to collect the lasers 6 and transmit them through partially transmitting mirror 78.
7 In Figure 13, an apparatus is shown for conveyin~ the 8 laser beam 79 from the laser generating apparatus 80 to the 9 article 81 to be treated. The beam is turned by a mirror 82 and gathered by a lens 83 having an assist gas inducted 11 therein at 84. The beam orifice 85 controls the beam sPot size 12 at the article interface.
13 Laser surface alloying is particularly useful in those 14 applications of the prior art where: (a) the surface of an article requires a special alloy composition for wear, corrosion 16 or heat resistance, (b) an irregular pattern on the surface 17 requires a special alloy composition, (c) the required alloy 18 content cannot be produced economically in the cast or wrought 19 condition, (d) different compositions are necessary at different locations of the surface of an article, (e) a metallurgical 21 bond between the special surface layer and the base material 22 is desirable, (f) the heat affected zone in the base material 23 should be minimized, (g) the surface alloying must be accomplished 24 with a minimum heat input to reduce distortion and damage of an adjacent component by excessive heat, and (h) the hardened 26 case should possess a high hardness even at an elevated 27 temperature.
28 ~et still another apparatus useful in generating a 29 high energy beam for this invention is shown in Figure 15. The apparatus is an electron gun which transmits a beam of electrons 1~3343;~
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1 86 derived from a heated filament or an indirectly-heated 2 cathode 87. The control electrode 88 regulates beam current 3 and voltage of anode 89, and thereby the velocity of electrons 4 in the beam. The product of anode voltage and beam current is beam power. The focus coil ~0 controls beam spot size 6 independently so that beam spot size can be adjusted as 7 desired for various values of voltage and standoff. Deflection 8 coils 91 move the beam away from its neutral axis position to 9 direct the beam onto any point on the article 92. Four coils are usually required to deflect the beam in both X and Y
11 directions in the plane of the article. The article and gun 12 share essentially the same vacuum chamber 93.
13 (5) Lastly tne influence of the beam must be removed 14 from a properly melted zone of the article at a sufficiently rapid rate, the mass of the article must be proportioned to the 16 volume of the molten melted zone and the article metal must 17 have been selected with an adequate thermal conductivitY to 18 achieve rapid self-quenching and thereby the formation of small 19 particles of intermetallic compounds, when desired, or a saturated solid solution, when desired. In almost all cases 21 where the article is a casting and the beam affected zone is 22 1/8" or les~, the mass will be properly proportioned.
23 Heat Treating 24 The main purpose of surface heat treatment according to this invention is to improve the surface wear characteristic 26 or fatigue life of non-allotropic metal articles with minimum 27 distortion. This is accomplished by manipulation of a defocused 28 beam or oscillation of a focused beam, both without the use of 29 independent alloying agents, to rapidly remelt the selected zone -, , .
', ~ . . . ! , 1 of the article and self-quench. The mechanism of hardening 2 is grain and particle refinement; this may also result in 3 increased solid solution hardening by rapid quenching which 4 facilitates to obtain super saturated solid solution.
As shown in Figure 7, heat treatment is carried out 6 by deploying a hign energy beam 52 having a power level of at 7 least 10,000 watts/cm2 to remelt a typical non-allotropic 8 base metal; the energy is concentrated in a beam so that upon 9 contact with tne untreated surface of the article, sufficient ; 10 energy will heat the interface zone 54 to melting and the 11 base metal to much greater depths (55) typically about .25".
12 Such beam can be generated by either a laser or an electron 13 beam apparatus 53. ~y controlling the rate of movement of 14 the beam, and proportioning the mass of the article 56 with respect to the beam affected zone 54, rapid quenching will take 16 place upon removal of the high energy beam from each beam 17 affected station.
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9 EIigh intensity energy heat sources have been employed for purposes of welding, cutting and drilling, and in certain 11 limited modes for the purpose of surface hardening of ferrous-12 based materials. The high energy beam can be employed to melt 13 a very shallow surface region of an iron based article with 14 the result that the melted material can be transformed to a harder phase upon removal of the energy beam, allowing the 1~ article to perfor~ as a self-quenching medium. However, the 17 technique of using a high energy beam for surface hardening 18 ferrous-based material is totally different than its use when 19 applied to non-ferrous and particularly non-allotropic materials.
Little or no thought has been given to the concept of 21 controlling the introduction of alloying ingredients to con-22 trolled depths and proportions within a non-allotropic metal 23 base, such as aluminum,by the use of a high energy beam. The 24 lack of investigation may be attributed to the prevailing thought that the usefulness of such a beam, when applied to 26 aluminum, would be limited because (a) melting typically does 27 not lead to a hardened transformed phase within such material, 2~ (b) past experience with furnace heat treatment indicated 29 limited hardness levels to which many non-allotropic metals could be hardened, (c) the lack of commercial need to -~
1 investigate how to deep harden localized zones with little 2 distortion, and (d) the availability of alternate hardening 3 techniques for co~mercial needs which usually were shallow 4 non-severe wear surfaces, one technique being plasma spraying S which did not distort the substrate and was very flexible in 6 use. Thus, utility of a highly concentrated energy beam 7 had not been envisioned in applications involving aluminum 8 and the like.
9 Particularly with respect to aluminum, one or more of the following disadvantages may occur with present technology:
11 ~a) the article may be highly distorted as a result of the 12 hardening treatment, (b) the surface contour of the part to be 13 treated may be irregular and therefore is not susceptible to 14 uniform treatment or the article may have different sections and the different sections respond differently to the 16 hardening treatment causing non-uniformity, (c) the cost of 17 hardening an aluminum article may be relatively high due to 18 the requirement for expensive equipment or manpower, (d) the 19 method of heat treatment is unable to achieve a shallow uniform case depth with accuracy, (e) the method of treatment is 21 unable to achieve selective precision patterns of case 22 hardening over a given surface, (f) the prior art method is 23 unable to economically harden a small area of a large sized 24 article,~g) the prior art method is unable to harden small areas which are difficult to reach within a complex part, 26 (h) the prior art method is unable to be used without potential 27 damage of adjacent parts, (i) quenching becomes difficult 28 at best with certain of the prior art methods, and (j) the 29 prior art methods do not lend themselves to extremely high volume and fast rates of production. Accordingly, there is a 31 need for a method of surface treating aluminum articles, and the - . .
1093~133 like, which overcomes the above problems and in additiop improves the surface treating technology for non-allotropic materials to facilitate achieving all desirable physical properties with adequate control.
In accordance with the present invention, there is provided a method of treating a selected exposed region of a non-allotropic metal article for enhancing the physical properties of the region, comprising: (a) selecting the non-allotropic metal for the article having a thermal conductivity of at least 0.25 Cal./cm2/cm/sec~/C; (b) directing a high energy beam at an exposed region of the article to heat the article at a first zone and to melt the article at a second zone within the first zone to a predetermined depth, the beam providing an energy level at the interface with the article of at least 10,000 watts/
cm2; ~c) controlling the area of the beam interface, beam energy level, and rate of displacement of the beam along the article to restrict the first zone to a predetermined volume and ensure a predetermined fast heat-up rate of the first zone; and (d) proportioning the mass of the article to the volume of the first zone to provide a fast self-quenching cooling rate of the first zone upon removal of the influence of the beam therefrom whereby a fine grain structure and fine particles are promoted in at least the second zone.
The present invention overcomes the problems of the prior art by permitting treatment of a precisely selected exposed generally small zone of a non-allotropic metal article to achieve physical properties in that zone here-tofore unattainable. This treatment is achieved withoutdetrimentally affecting the remainder of the article.
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~0~3433 The invention is described further, by way of illustra-tion, with reference to the accompanying drawings, in which:
` Figure 1 is a schematic sectional illustration of one early step in practicing a preferred method mode of the :
present invention; the method mode involves alloying a case onto a metal substrate;
Figure 2 is a schematic sectional illustration of a subsequent step for the method mode of Figure 1, particularly involving the melting of both an alloy layer and a subjacent zone of the base metal;
Figure 3 is a schematic sectional illustration of the resulting product from practicing the steps of Figures 1 and 2, the product having been subjected to a single pass of the melting apparatus;
Figure 4 is a sectional view taken substantially along line 4-4 of Figure 3 illustrating the depth and con-tinuity of the single pass;
Figure 5 is a sectional view similar to Figure 3 but showing the result of a multiple overlapping pass of said 2~ melting apparatus;
Figure 6 is a scnematic sectional view, similar to that of Figure 2, showing an alternative mode of carrying out the first and second steps simultaneously; ~ .,.
~Figure 7 is a schematic sectional view of another process mode of this invention directed to heat treatment with no surface alloying;
Figure 8 is an enlarged schematic view of a portion of the workpiece operated upon by the method of Figure 7 showing the flow of energy input and energy dissipation;
Figures 9-11 scnematically depict different laser generating apparatus useful with this invention;
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iO93433 Figure 12 is a schematic view of a laser concen-trating apparatus for directing the beam at an article to be heated;
Figure 13 is a schematic illustration of one type of plasma powder coating apparatus that may be employed in connection with the method of Figures 1-3; and Figure 14 is a schemati~c perspective view of one type of electron beam apparatus that may be employed in practicing the invention.
The general concept of this invention is to obtain enhanced physical properties in a treated zone along the outer region of an article constit,uted of a non-allotropic metal (of sufficiently high thermal conductivity) without detri-mentally affecting the remainder of the article. The treated zone is typically arranged to be extremely small in comparison to the mass of the article for cost-saving benefits. The method comprises essentially heating and cooling. Heating consists of concentrating a high energy beam and directing such beam toward a delimited zone of the surface of the article at predetermined scan rate and energy level measured at the article interface so as to melt the metal in said zone at a sufficiently fast rate thereby isolating the remainder of the article from the heat up effect. Cooling consists of removing the high energy beam from said zone while proportioning the mass of qaid article with respect to the beam affected zone to provide a self-quenching cooling rate which insures a fine grained structure and a supersaturated solid solution. The supersaturated solution can be promoted by either diffusing independent alloying ingredients into said zone for a ., s .
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1093a~33 1 controlled dilution of the metal or by selecting an alloyed 2 base metal having a minimum level of inherent alloying 3 ingredients for supersaturation.
4 The most notable advantage achieved by practicing such method is the capability of deploying a relativelv 6 economical light substrate material, such as aluminum, and 7 the capability of restricting physical property enhancement 8 by isolating use of expensive materials to small selected 9 surface zones, therçby producing an excellent cost/performance ratio.
11 Surfa~e AlloYing 12 One of the important method modes of employing the 13 general concept provides an alloyed surface zone on the article.
14 Surface alloying is achieved by rapidly melting the selected outer zone of the article as well as an alloying agent 16 deposited previously or simultaneously into said zone. The 17 alloying agent is turbulized into the melted base metal by 18 thermal activity resulting from the action of the beam.
19 Upon quick removal of the high energy beam, a self-quenching operation ensues creating a fine grained solid solution alloy 21 with distribution of intermetallic compounds. The creation of 22 such homogeneous surface alloy region is new because at least 23 so~e investigators thought that such high thermal conductivity 24 non-allotropic metals would lose strength as a result of high energy beam exposure. And yet some others may have thought 26 that the beam affected zone would not be limited adequately to 27 permit self-quenching. It was found that the beam affected 28 zone can be most accurately limited, isolated and controlled 29 without sacrifice of needed heat up rate and self-quench rate.
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: :` 1093433 1 Turning more specifically to a detailed preferred 2 mode of carrying out surface alloying, reference is made to 3 Figures 1-6, 4 (1) An initial preparatory step of the process is to select a base material which responds to rapid heating by 6 a high energy beam, is easily melted, and will satisfactorily 7 thermally conduct heat during cooling for self-quenching.
8 Although a wide variety of metal materials can be employed, 9 the mode herein is preferably carried out with a base metal consisting essentially of an aluminum alloy. The base material 11 should have a thermal conductivity of at least .25 Cal./cm7/cm/
12 sec./C. Other non-allotropic metals as defined herein and 13 which have a sufficient thermal conductivity comprise:
14 magnesium, copper, zinc and titanium.
(2) The preferred base metal is surface alloyed by 16 the selection and use of alloy ingredients which have an 17 affinity for forming solid so}ution and intermetallic compounds 18 with the base metal. For aluminum or an aluminum alloy, the 19 ingredient can be selected from the group consisting of:
copper, nickel, tungsten, molybdenum, zirconium, vanadium, 21 magnesium, zinc, chromium cobalt, manganese and titanium.
22 Two or more of such ingredients may be added together. Copper 23 is one of the most effective alloying ingredients for 24 hardening aluminum alloys. Nickel facilitates resisting softening of the aluminum at elevated temperatures in the alloyed 26 condition. Silicon, although not forming an intermetallic 27 compound, is useful in an aluminum alloy to produce a low 28 silicon core with wear resistant high silicon surface having 29 independent wear particles. Graphite, although not forming an intermetallic compound, is useful as a high temperature solid ` ~0~343~
1 lubricant in the alloyed surface area. Alloy ingredients 2 for magnesium may include zinc, rare earth, zirconium, 3 manganese and aluminum. Alloy ingredients for copper may 4 include; lead, zinc, aluminum, tin, iron, nickel, silicon, manganese, beryllium, zirconium and chromium.
6 (3) The next step is to attach, deposit or subject 7 alloy ingredients to the beam adjacent the selected zone of 8 the base metal. One way this is accomplished is by depositing 9 an alloy layer 10 on the base metal 11 by a suitable mechanism 12 ~see Figure 10), which here includes plasma stream spraying 11 of powdered alloy metal. A preferable mode is to employ a 12 wire comprised of the alloying ingredients and feed such wire 13 into the beam (see Figure 6). vet another way is mix resin with 14 the powdered ingredients and deposit such mixture in tne path of the beam. Painting may also be employed, as long as the 16 ingredients are attached in a manner to be influenced by the 17 beam. The alloying ingredients, to be sprayed by the plasma 18 technique, can be an admixture of metal powders or can be l9 applied in independent layers. The admixed powders typically will be subjected to a very high temperature and subjected to 21 a jet velocity, however both conditions not being critical to 22 this invention.
23 The depth of the alloy layer should be controlled to 24 achieve a predetermined alloy concentration of the melted zone of the base metal. The alloying ingredients (whether added 26 or inherent in the base metal alloy) should enrich the base 27 metal melted zone to at least form a saturated solid solution 28 upon remelt. r.enerally, surface alloying will be directed pre-29 dominantly at enhancing one of three of physical characteristics (wear, fatigue life, or corrosion resistance) depending on the ,~
1(~93433 1 application and use of the treated article. To provide optimum 2 wear resistance in the treated zone of the article, the alloy 3 ingredients should be added to the melted base metal in 4 said zone in a weight ratio of 1:1 to 1:20. This may be roughly estimated by applying an alloy coating thickness which 6 is equal to or as little as 1/~ the (depth) thickness of the 7 melted base metal. This ran~e of ratios insures the generation 8 of intermetallic compounds in the melted zone upon solidifi-9 cation, which compounds constitute the primary mechanism of this invention to harden non-allotropic ~ase metals via a high 11 energy beam remelt.
12 To provide optimum fatigue life in the selected 13 surface treated zone, the ratio should range from 1:10 to 1:20 14 to provide a lean alloy dilution content and insure the avoidance of intermetallic compounds while promoting hardening 16 by precipitation or age hardening.
17 To provide an improvement in corrosion resistance 18 in the selected surface treated zone, the ratio should be no 19 less than 2:1. It may be preferable to use substantially pure aluminum for the alloying ingredient when the base metal 21 is an aluminum alloy, such as 390 or 355. ~urer aluminum has 22 a greater resistance to corrosion than said aluminum alloys.
23 A typical apparatus for carrying out the plasma 24 deposition is shown in Figure 10. The arrangement employs a plasma gun 15 containing a gas arc chamber 16 having an exit 26 throat which has a straight bore section 17 and a diverging 27 section 18. The gas supply 31 is introduced at the left han,~
28 portion of the gas chamber 16 and an arc is created acrOss the 29 chamber by virtue of an arc power supply 19. The metallic and refractory powders are introduced to the gun from a powder . .. . . . - : .
1 feeder 20 and carried to a preheating tube 21 which is 2 powered by a powder preheat supply 22; the powder is then 3 conveyed to a precise location in the exit throat by way of 4 a passage 23 which is slightly angled (at 24 with reference to a centerline 25 o~ the passage) and enters the exit 6 throat precisely at the juncture of the straight bore section 7 and the diverging section. The stream 13 from the plasma 8 gun is directed at the target article 26 to be coated. The 9 article to be coated is carried by movable support 27 so as to allow for the deposition of the powders across a wide 11 selected area or pattern. The workpiece or article 26 is 12 maintained at a specific electrical potential by way of a 13 transferred arc power supply 28 so as to receive plasma spray 14 particles. The entire workpiece, as well as plasma jet, is enclosed in a chamber 29 evacuated by a vacuum pump 30.
16 (4) As shown in Figure 2, the next step is to melt 17 by generating, directing and moving a high energy beam. A
18 high energy beam is defined herein to mean a column of radiant 19 energy (regardless of source) having an average power density in excess of 10,000 W/cm2 at the interface with the metal to 21 be treated. This step involves generation of a high energy 22 beam 32 of sufficient power, directing the beam at a selected 23 exposed zone 33 of the article and moving the high energy beam 24 32 along a predetermined path and at a specific rate so as to not only melt the selected zone of contact between the beam and 26 alloy layer 10 but also to melt a predetermined portion 34 of 27 the subjacent portion of the base metal 11. The beam will affect 28 two zones, first one which is heat influenced without melting 29 and a second zone within the first which is melted. Laser rays initially are slightly retarded by reflectivity from entering 11~93~33 1 a bare aluminum surface; this retardation is lessened by 2 (a) formation of a melted cavity when heat breaks down the 3 surface thereby permitting concentration of the rays and 4 (b) by the application of a powder alloy coating. Laser rays enter the article at the interface with high energy, but 6 with a defocused beam at least some of that intensity is lost ~y 7 reflectivity, diffusivity and refraction within the article.
8 However, this favors control of a shallow beam influenced 9 zone.
The heat-up rate of the base metal must be relatively 11 rapid so that ta) turbulence is created within the molten spot 12 pool and (b) removal of the high energy beam facilitates 13 rapid quenching. The absorptive characteristic of the base 14 metal must be controlled to assist entering of the beam rays into the base metal and thereby promote a fast heat-up rate.
16 This necessitates use of a laser beam or an electron beam.
17 It has been found by experimental procedure that ~o achieve 18 melting of the deposited alloy layer 10 (consisting of 19 silicon, copper, nickel and carbon) having a thickness of .006" (35) and to melt the subjacent base metal 11 to a depth 21 of .~25" (36), the energy imparted to the article at its 22 surface 37 must be about 70,000 watts/cm2 with a beam spot 23 diameter at the interface of .08". This can be obtained by 24 use of a laser beam generated by an apparatus 38 (disclosed in any of Figures 10-13). The definition of a proper high 26 energy laser beam for carrying out surface alloying is critical.
27 The apparatus for generating the beam must have a power rating 28 of at least 1-6 KW to achieve rapid heating and melting with 29 a commercial scan rate of .005 in.2/sec. At power levels lower than 1 KW, the beam speed can operably be as low as ; ' ' ~' ', ' ,.;~
1 .01"/minute, but this speed is commercially impractical. The 2 beam 32 should be focused to a point 40 located a distance 41 3 away from the plane of the outer surface 37 of the article 4 (either above or below); thus, the beam is defocused with respect to the interface with the outer surface of the article 6 and has a diameter 39 at said interface which may vary 7 practically between .01-.5" in diameter.
8 It is important to control interplay of the power g level of the high energy beam, the scan speed or relative vement of the beam across the surface 37 of the article, 11 and the spot size of the beam at the interface. Moreover, 12 n controlling" used hereinafter means correlating the beam 13 interface area, scan speed, and beam energy level to achieve 14 a desired melt rate and cooling rate for the beam affected zone. The energy level at the interface should be at least 16 10,000 watts/cm2; the spot size at the interface can vary 17 from .0008 in.2 to .0~ in.2 or more. The linear speed should 18 be in the range of l~-100"/minute. Proper control of these 19 parameters results in successful temperature distribution in the base metal and successful laser surface alloying.
21 The resulting alloyed case depth 42 from a single 22 pass is basically proportional to the energy application level 23 used at a given scan rate. The exact values of the power 24 level as related to the scan rate for particular surface alloying material or application will depend upon the alloy 26 coating, the base metal, and the alloyed case depth desired.
27 l'he resulting depth 42 of the alloyed case or beam affected zone 28 is shown in Figure 3. The zone for a single pass is represented 29 in cross-section by a semi-spnerical filled groove 43 having a solid solution of alloyed metal containing intermetallic "
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~093433 l compounds. You will note the top surface 44 of the resulting 2 alloyed zone is higher than the original surface of the 3 article.
4 Figure 4 illustrates the contour of the single pass S along its length. ~ complete surface of the article may be 6 provided with an alloyed case by (1) establishing multiple 7 passes of a defocused beam and (2) overlapping the zone of 8 influence of each pass so that the beam affected zone 45 will 9 appear as a number of overlapping ribs 46-47 as shown in Figure 5. The spacing and degree of overlapping of the ribs ll can be varied to establish a minimum zone depth 48. It is 12 quite possible that the passes may be separated by a wide 13 dimension so th~t only a pattern of alloyed ribbons or lands 14 may appear on the article, such lands of alloy may provide the necessary wear resistance for the entire surface. In 16 addition, the beam affected zone may be subject to a focused 17 beam (focused at the interface) and pulsated to keep the 18 energy level commensurate with melting.
l9 The preferred apparatus for generating a laser beam is shown in Figure lO and comprises a closed CO2 gas flow circuit 21 61, the gas being moved rapidly by a blower 62 and heat removal 22 by an exchanger 63. The laser discharge takes place axially 23 along the flow path between electrodes 64 and 65. The laser 24 beam discharge is trained in said axial flow direction by totally transmitting mirror 66 and emitted from the laser 26 generator housing through partially transmitting mirror 67.
27 In Figure ll, there is shown an apparatus for 28 generating a laser beam from gas with a flow 68 transverse to 29 the electrical discharge between electrodes 69 and 70. ~irror 71 is partially transmitting.
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10~3433 1 In Figure 12, there is shown an apparatus for 2 generating a laser by an electron beam 72; sustainer electrodes 3 73 and 74 are spaced apart in a high vacuum; the electron 4 emitter 75 sends electrons through membrane 76 to the S electrodes. ~irrors 77 and 78 cooperate to collect the lasers 6 and transmit them through partially transmitting mirror 78.
7 In Figure 13, an apparatus is shown for conveyin~ the 8 laser beam 79 from the laser generating apparatus 80 to the 9 article 81 to be treated. The beam is turned by a mirror 82 and gathered by a lens 83 having an assist gas inducted 11 therein at 84. The beam orifice 85 controls the beam sPot size 12 at the article interface.
13 Laser surface alloying is particularly useful in those 14 applications of the prior art where: (a) the surface of an article requires a special alloy composition for wear, corrosion 16 or heat resistance, (b) an irregular pattern on the surface 17 requires a special alloy composition, (c) the required alloy 18 content cannot be produced economically in the cast or wrought 19 condition, (d) different compositions are necessary at different locations of the surface of an article, (e) a metallurgical 21 bond between the special surface layer and the base material 22 is desirable, (f) the heat affected zone in the base material 23 should be minimized, (g) the surface alloying must be accomplished 24 with a minimum heat input to reduce distortion and damage of an adjacent component by excessive heat, and (h) the hardened 26 case should possess a high hardness even at an elevated 27 temperature.
28 ~et still another apparatus useful in generating a 29 high energy beam for this invention is shown in Figure 15. The apparatus is an electron gun which transmits a beam of electrons 1~3343;~
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1 86 derived from a heated filament or an indirectly-heated 2 cathode 87. The control electrode 88 regulates beam current 3 and voltage of anode 89, and thereby the velocity of electrons 4 in the beam. The product of anode voltage and beam current is beam power. The focus coil ~0 controls beam spot size 6 independently so that beam spot size can be adjusted as 7 desired for various values of voltage and standoff. Deflection 8 coils 91 move the beam away from its neutral axis position to 9 direct the beam onto any point on the article 92. Four coils are usually required to deflect the beam in both X and Y
11 directions in the plane of the article. The article and gun 12 share essentially the same vacuum chamber 93.
13 (5) Lastly tne influence of the beam must be removed 14 from a properly melted zone of the article at a sufficiently rapid rate, the mass of the article must be proportioned to the 16 volume of the molten melted zone and the article metal must 17 have been selected with an adequate thermal conductivitY to 18 achieve rapid self-quenching and thereby the formation of small 19 particles of intermetallic compounds, when desired, or a saturated solid solution, when desired. In almost all cases 21 where the article is a casting and the beam affected zone is 22 1/8" or les~, the mass will be properly proportioned.
23 Heat Treating 24 The main purpose of surface heat treatment according to this invention is to improve the surface wear characteristic 26 or fatigue life of non-allotropic metal articles with minimum 27 distortion. This is accomplished by manipulation of a defocused 28 beam or oscillation of a focused beam, both without the use of 29 independent alloying agents, to rapidly remelt the selected zone -, , .
', ~ . . . ! , 1 of the article and self-quench. The mechanism of hardening 2 is grain and particle refinement; this may also result in 3 increased solid solution hardening by rapid quenching which 4 facilitates to obtain super saturated solid solution.
As shown in Figure 7, heat treatment is carried out 6 by deploying a hign energy beam 52 having a power level of at 7 least 10,000 watts/cm2 to remelt a typical non-allotropic 8 base metal; the energy is concentrated in a beam so that upon 9 contact with tne untreated surface of the article, sufficient ; 10 energy will heat the interface zone 54 to melting and the 11 base metal to much greater depths (55) typically about .25".
12 Such beam can be generated by either a laser or an electron 13 beam apparatus 53. ~y controlling the rate of movement of 14 the beam, and proportioning the mass of the article 56 with respect to the beam affected zone 54, rapid quenching will take 16 place upon removal of the high energy beam from each beam 17 affected station.
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Claims (24)
1. A method of treating a selected exposed region of a non-allotropic metal article for enhancing the physical properties of said region, comprising:
(a) selecting the non-allotropic metal for said article having a thermal conductivity of at least .25 Cal.
cm2/cm/sec. /°C, (b) directing a high energy beam at an exposed region of said article to heat said article at a first zone and to melt said article at a second zone within said first zone to a predetermined depth, said beam providing an energy level at the interface with said article of at least 10,000 watts/cm2, (c) controlling the area of said beam interface, beam energy level, and rate of displacement of said beam along said article to restrict said first zone to a predetermined volume and ensure a predetermined fast heat-up rate of said first zone, and (d) proportioning the mass of said article to the volume of said first zone to provide a fast self-quenching cooling rate of said first zone upon removal of the influence of said beam therefrom whereby a fine grain structure and fine particles are promoted in at least said second zone.
2. The method as in Claim 1, which further includes, either prior to or simultaneous with directing a high energy beam at said article, introducing a molten alloying ingredient to said second zone to be mixed with the metal thereof, said alloying ingredient comprising a material having
(a) selecting the non-allotropic metal for said article having a thermal conductivity of at least .25 Cal.
cm2/cm/sec. /°C, (b) directing a high energy beam at an exposed region of said article to heat said article at a first zone and to melt said article at a second zone within said first zone to a predetermined depth, said beam providing an energy level at the interface with said article of at least 10,000 watts/cm2, (c) controlling the area of said beam interface, beam energy level, and rate of displacement of said beam along said article to restrict said first zone to a predetermined volume and ensure a predetermined fast heat-up rate of said first zone, and (d) proportioning the mass of said article to the volume of said first zone to provide a fast self-quenching cooling rate of said first zone upon removal of the influence of said beam therefrom whereby a fine grain structure and fine particles are promoted in at least said second zone.
2. The method as in Claim 1, which further includes, either prior to or simultaneous with directing a high energy beam at said article, introducing a molten alloying ingredient to said second zone to be mixed with the metal thereof, said alloying ingredient comprising a material having
Claim 2 cont.
an affinity for said non-allotropic metal to form an inter-metallic compound therewith.
an affinity for said non-allotropic metal to form an inter-metallic compound therewith.
3. The method as in Claim 2, in which said beam interface with said article and the depth of said second zone are each controlled to promote turbulence of the melted metal for thorough mixing of said melted alloying ingredient thereinto prior to solidification.
4. The method as in Claim 1, in which said beam is comprised of lasers and said metal article is comprised of aluminum or an aluminum alloy.
5. The method as in Claim 4, in which said article mass beneath said first zone has a thickness of at least 5 times the depth of said first zone.
6. The method as in Claim 1, in which said beam is comprised of electrons and said metal article is comprised of aluminum or an aluminum alloy.
7. The method as in Claim 1, in which the high energy beam is comprised of rays controlled like visible light rays, said beam having a focal point out of the plane of the surface of said exposed region whereby the beam interface area with said region is controlled to be at least .00003 square inches.
8. The method as in claim 1, in which said beam is moved across said region along a translating and oscillatory path.
9. The method as in claim 1, in which said beam is pulsated to achieve either an interrupted first zone or to affect a predetermined controlled depth of said second zone.
10. A method of alloying a selected exposed region of a non-allotropic metal article for enhancing the physical properties of said region, comprising the steps of:
(a) providing a non-allotropic metal casting to constitute said article, said metal having a thermal conductivity of at least 0.25 Cal./cm2/cm/sec./°C, (b) placing an alloying ingredient adjacent said exposed region, said alloying ingredient comprising sub-stantially a material having an affinity to form inter-metallic compounds with said non-allotropic metal, (c) directing a high energy beam at said selected exposed region of said article to heat said article at a first zone and to melt said article at a second zone within said first zone to a predetermined depth and to melt an amount of said alloying ingredient proportioned to said second zone, said beam providing an energy level at the interface with said article of at least 10,000 watts/
cm2, (d) controlling the area of interface of said beam with said region, beam energy level, and rate of displace-ment of said beam along said article to restrict said first zone to a predetermined volume for insuring a fast heat-up rate of said first zone and to create a turbulence in said melted metal and melted alloying ingredient, and (e) proportioning the mass of said article to the volume of said first zone to provide a fast self-quenching cooling rate of said first zone upon removal of the influence of said beam therefrom whereby a fine grain structure and fine particles are promoted in at least said second zone.
(a) providing a non-allotropic metal casting to constitute said article, said metal having a thermal conductivity of at least 0.25 Cal./cm2/cm/sec./°C, (b) placing an alloying ingredient adjacent said exposed region, said alloying ingredient comprising sub-stantially a material having an affinity to form inter-metallic compounds with said non-allotropic metal, (c) directing a high energy beam at said selected exposed region of said article to heat said article at a first zone and to melt said article at a second zone within said first zone to a predetermined depth and to melt an amount of said alloying ingredient proportioned to said second zone, said beam providing an energy level at the interface with said article of at least 10,000 watts/
cm2, (d) controlling the area of interface of said beam with said region, beam energy level, and rate of displace-ment of said beam along said article to restrict said first zone to a predetermined volume for insuring a fast heat-up rate of said first zone and to create a turbulence in said melted metal and melted alloying ingredient, and (e) proportioning the mass of said article to the volume of said first zone to provide a fast self-quenching cooling rate of said first zone upon removal of the influence of said beam therefrom whereby a fine grain structure and fine particles are promoted in at least said second zone.
11. The method as in claim 10, in which the amount of alloying ingredient melted and dissolved in the second zone of said article is proportioned to be within the range of 1:1 to 1:20 (alloying ingredient: non-allotropic metal in said second zone) whereby said second zone will have a solidification structure characterized by a uniform fine grain structure, a high degree of enrichment of alloying elements of the metal in said zone, and a homogeneous distribution of intermetallic compounds rendering an enhanced hardness level.
12. The method as in claim 10, in which the amount of alloying ingredient melted and dissolved in the second zone of said article is proportioned to be within the range of 1:10 to 1:20 (alloying ingredient: non-allotropic metal in zone) whereby said second zone will have a solidification structure principally providing increased fatigue life characterized by a uniform fine grain structure, absence of intermetallic compounds and a solid solution promoting age hardening.
13. The method as in claim 10, in which the amount of alloying ingredient melted and dissolved in the second zone of said article is proportioned to be at least 2:1 (alloying ingredient: non-allotropic metal in zone) whereby said second zone will be changed in base and have a solidification structure principally providing increased corrosion resistance.
14. The method as in claim 13, in which said alloying ingredient is aluminum and said non-allotropic metal is an aluminum alloy containing less than 5% of alloying ingredients.
15. The method as in claim 10, in which said beam is moved with respect to said metal casting along a plurality of translating paths, said paths being adjacent one another so as to overlap and provide for contiguous zones on said article.
16. The method as in claim 10, in which said beam is generated by an apparatus having a 0.5 kilowatt rating of at least 2.
17. The method as in claim 10, in which said beam is comprised of lasers and said non-allotropic metal is aluminum based.
18. The method as in claim 10, in which said non-allotropic metal has a reflective surface, said metal casting region being coated with an energy beam absorption material to facilitate absorption of the rays of said beam within said casting.
19. The method as in claim 18, in which said absorptive coating is arranged in a predetermined pattern for selecting treatment of the surface of said metal coating.
20. The method as in claim 10, in which the alloying ingredient is deposited as a coating on said metal casting prior to the application of said high energy beam, said deposition being carried out by plasma stream whereby the alloying ingredient is mechanically and molecularly locked to the surface of said casting along said first zone.
21. The method as in claim 10, in which the alloying ingredient is formed as a wire, said wire being fed into said high energy beam to be melted and carried into said second zone.
22. The method as in claim 10, in which the alloying ingredients are mixed with resin and brushed on said non-allotropic metal prior to directing said high energy beam at said exposed region.
23. The method as in claim 10, in which the alloying ingredients are in powder form and are fed into said high energy beam to be melted and alloyed with said non-allotropic metal.
24. The method as in claim 1, in which said beam is moved along a plurality of separated and spaced paths whereby the beam affected zones form spaced lands on the exposed surface of said article.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US05/722,965 US4157923A (en) | 1976-09-13 | 1976-09-13 | Surface alloying and heat treating processes |
| US722,965 | 1976-09-13 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1093433A true CA1093433A (en) | 1981-01-13 |
Family
ID=24904216
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA281,514A Expired CA1093433A (en) | 1976-09-13 | 1977-06-28 | Surface alloying and heat treating processes |
Country Status (8)
| Country | Link |
|---|---|
| US (1) | US4157923A (en) |
| JP (1) | JPS6037176B2 (en) |
| CA (1) | CA1093433A (en) |
| DE (1) | DE2740569B2 (en) |
| ES (1) | ES462164A1 (en) |
| FR (1) | FR2371520A1 (en) |
| GB (1) | GB1587235A (en) |
| IT (1) | IT1079283B (en) |
Families Citing this family (123)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4401726A (en) * | 1974-01-07 | 1983-08-30 | Avco Everett Research Laboratory, Inc. | Metal surface modification |
| US4322601A (en) * | 1978-08-14 | 1982-03-30 | Serlin Richard A | Surface alloying method and apparatus using high energy beam |
| BR7806091A (en) * | 1978-09-15 | 1980-03-25 | Metal Leve Sa Ind Com | PROCESS FOR THE BENEFIT OF ANTI-FRICTION ALLOY STEEL COATING ALLOYS, THE BENEFIT COMPOUND STRIPS AND PRODUCTS OBTAINED FROM SUCH STRIPS |
| GB2052566B (en) * | 1979-03-30 | 1982-12-15 | Rolls Royce | Laser aplication of hard surface alloy |
| JPS55148752A (en) * | 1979-05-11 | 1980-11-19 | Nippon Steel Corp | Formation method of coating on metal surface |
| DE2930552C2 (en) * | 1979-07-27 | 1984-02-09 | Mahle Gmbh, 7000 Stuttgart | Reinforced bars in the ring belt of an aluminum piston |
| DE2948057A1 (en) * | 1979-11-29 | 1981-06-04 | Karl Schmidt Gmbh, 7107 Neckarsulm | METHOD FOR DESIGNING THE EDGE OF A COMBUSTION TUB OF A LIGHT METAL PISTON |
| JPS589151B2 (en) * | 1980-02-13 | 1983-02-19 | ペルメレック電極株式会社 | Method of forming a corrosion-resistant coating on a metal substrate |
| JPS5948873B2 (en) * | 1980-05-14 | 1984-11-29 | ペルメレック電極株式会社 | Method for manufacturing electrode substrate or electrode provided with corrosion-resistant coating |
| US4299860A (en) * | 1980-09-08 | 1981-11-10 | The United States Of America As Represented By The Secretary Of The Navy | Surface hardening by particle injection into laser melted surface |
| US4348263A (en) * | 1980-09-12 | 1982-09-07 | Western Electric Company, Inc. | Surface melting of a substrate prior to plating |
| US4495255A (en) * | 1980-10-30 | 1985-01-22 | At&T Technologies, Inc. | Laser surface alloying |
| US4498926A (en) * | 1981-03-20 | 1985-02-12 | General Electric Company | Method for producing eutectics as thin films using a laser device as a heat source |
| US4498924A (en) * | 1981-03-20 | 1985-02-12 | General Electric Company | Method for producing eutectics as thin films using a line heater |
| US4498923A (en) * | 1981-03-20 | 1985-02-12 | General Electric Company | Method for producing eutectics as thin films using a quartz lamp as a heat source in a line heater |
| EP0079897A1 (en) * | 1981-04-28 | 1983-06-01 | Ae Plc | Piston manufacture |
| DE3126953C2 (en) * | 1981-07-08 | 1983-07-21 | Arnold, Peter, Dr., 8000 München | Process for the thermal treatment of the surface of workpieces by means of a linearly polarized laser beam |
| US4477324A (en) * | 1981-11-13 | 1984-10-16 | General Electric Company | Making metal eutectic fine wire arrays |
| WO1983002415A1 (en) * | 1982-01-20 | 1983-07-21 | Birley, Stuart, Samuel | Improvements in or relating to fusion welding methods |
| US4934254A (en) * | 1982-05-24 | 1990-06-19 | Clark Eugene V | Face seal with long-wearing sealing surface |
| US4451302A (en) * | 1982-08-27 | 1984-05-29 | Aluminum Company Of America | Aluminum nitriding by laser |
| JPS5939364U (en) * | 1982-09-07 | 1984-03-13 | 日本ピストンリング株式会社 | floating seal |
| US4451299A (en) * | 1982-09-22 | 1984-05-29 | United Technologies Corporation | High temperature coatings by surface melting |
| DE3311891A1 (en) * | 1983-03-31 | 1984-10-04 | Bayer Ag, 5090 Leverkusen | BAND-SHAPED FILMS OF METALS, METHOD AND DEVICE FOR THE PRODUCTION THEREOF AND THEIR USE |
| US4498925A (en) * | 1983-12-05 | 1985-02-12 | General Electric Company | Method for producing eutectics as thin films using an arc lamp, as a heat source in a line heater |
| US4613386A (en) * | 1984-01-26 | 1986-09-23 | The Dow Chemical Company | Method of making corrosion resistant magnesium and aluminum oxyalloys |
| JPS60187660A (en) * | 1984-02-24 | 1985-09-25 | Honda Motor Co Ltd | Partially hardened cast iron member |
| DE3415050A1 (en) * | 1984-04-21 | 1985-10-31 | Kabel- und Metallwerke Gutehoffnungshütte AG, 3000 Hannover | METHOD FOR PRODUCING A CONTINUOUS CASTING CHILL WITH A WEAR-RESISTANT LAYER |
| JPS60258481A (en) * | 1984-06-06 | 1985-12-20 | Toyota Motor Corp | Manufacture of surface coated member containing dispersed particles |
| IT1179061B (en) * | 1984-08-20 | 1987-09-16 | Fiat Auto Spa | PROCEDURE FOR CARRYING OUT A TREATMENT ON METAL PIECES WITH THE ADDITION OF A VALUE MATERIAL AND WITH THE USE OF A POWER LASER |
| DE3435460A1 (en) * | 1984-09-27 | 1986-04-10 | M.A.N. Maschinenfabrik Augsburg-Nürnberg AG, 8000 München | METHOD FOR PRODUCING WORKPIECES FROM LIGHT METAL |
| US4555275A (en) * | 1984-10-19 | 1985-11-26 | Grumman Aerospace Corporation | Hydrogen permeation protection for metals |
| GB8428410D0 (en) * | 1984-11-09 | 1984-12-19 | Ray A I A | Surgical cutting instruments |
| GB2169318A (en) * | 1985-01-04 | 1986-07-09 | Rolls Royce | Metal surface hardening by carbide formation |
| JPH0737660B2 (en) * | 1985-02-21 | 1995-04-26 | トヨタ自動車株式会社 | Improved treatment method of cylinder head for internal combustion engine made of cast aluminum alloy |
| DE3664930D1 (en) * | 1985-03-15 | 1989-09-14 | Bbc Brown Boveri & Cie | Process for enhancing the oxidation and corrosion resistance of a component made from a dispersion-hardened superalloy by means of a surface treatment |
| JPS6213521A (en) * | 1985-07-09 | 1987-01-22 | Honda Motor Co Ltd | Wear resistant member and its production |
| JPS6216894A (en) * | 1985-07-17 | 1987-01-26 | Toyota Motor Corp | Padding method for aluminum base metal |
| AU6109586A (en) * | 1985-08-13 | 1987-02-19 | Toyota Jidosha Kabushiki Kaisha | Alloy layer on al-alloy substrate using co2 laser |
| US4746540A (en) * | 1985-08-13 | 1988-05-24 | Toyota Jidosha Kabushiki Kaisha | Method for forming alloy layer upon aluminum alloy substrate by irradiating with a CO2 laser, on substrate surface, alloy powder containing substance for alloying and silicon or bismuth |
| JPS6293314A (en) * | 1985-10-21 | 1987-04-28 | Honda Motor Co Ltd | Wear resistant sliding member |
| FR2589485B1 (en) * | 1985-11-05 | 1991-12-13 | Nippon Telegraph & Telephone | MAGNESIUM OR SURFACE-TREATED MAGNESIUM ALLOY AND METHOD FOR THE SURFACE TREATMENT OF MAGNESIUM OR A MAGNESIUM ALLOY |
| FR2594852B1 (en) * | 1986-02-25 | 1988-04-29 | Cegedur | ALUMINUM PARTS AND ALLOYS HAVING AT LEAST ONE SIDE AT LEAST ONE REGION OF WEAR RESISTANT ZONES |
| DE3773258D1 (en) * | 1986-05-18 | 1991-10-31 | Daido Steel Co Ltd | WEAR-RESISTANT ITEMS MADE OF TITANIUM OR TITANIUM ALLOY. |
| EP0273547A3 (en) * | 1986-09-30 | 1988-08-31 | Kuroki Kogyosho Co., Ltd. | A method for producing amorphous metal layer |
| US4891183A (en) * | 1986-12-03 | 1990-01-02 | Chrysler Motors Corporation | Method of preparing alloy compositions |
| US4999158A (en) * | 1986-12-03 | 1991-03-12 | Chrysler Corporation | Oxidation resistant iron base alloy compositions |
| US4735771A (en) * | 1986-12-03 | 1988-04-05 | Chrysler Motors Corporation | Method of preparing oxidation resistant iron base alloy compositions |
| US4724299A (en) * | 1987-04-15 | 1988-02-09 | Quantum Laser Corporation | Laser spray nozzle and method |
| DE3715327A1 (en) * | 1987-05-08 | 1988-11-17 | Castolin Sa | Process for producing a wear-resistant coating |
| US4803334A (en) * | 1987-11-16 | 1989-02-07 | Westinghouse Electric Corp. | Method for laser beam welding metal matrix composite components |
| DE3808285A1 (en) * | 1988-03-12 | 1989-09-21 | Messer Griesheim Gmbh | Process for producing hard and wear-resistant surface layers |
| WO1989009843A1 (en) * | 1988-04-04 | 1989-10-19 | Chrysler Motors Corporation | Oxidation resistant iron base alloy compositions |
| DE3813802A1 (en) * | 1988-04-23 | 1989-11-09 | Glyco Metall Werke | LAYERING MATERIAL OR LAYERING MATERIAL WITH A FUNCTIONAL LAYER APPLIED ON A SUPPORT LAYER, IN PARTICULAR SLIDING LAYER WITH THE STRUCTURE OF A SOLID, BUT MELTABLE DISPERSION |
| SE463213B (en) * | 1988-05-06 | 1990-10-22 | Ibm Svenska Ab | DEVICE AND PROCEDURE TO ENSURE A METAL SUBSTRATE WITH A RESISTANT SURFACE |
| US4975335A (en) * | 1988-07-08 | 1990-12-04 | Fancy Steel Corporation | Fe-Mn-Al-C based alloy articles and parts and their treatments |
| CH675260A5 (en) * | 1988-07-19 | 1990-09-14 | Sulzer Ag | |
| US4905886A (en) * | 1988-07-20 | 1990-03-06 | Grumman Aerospace Corporation | Method for diffusion bonding of metals and alloys using thermal spray deposition |
| DE3922378A1 (en) * | 1989-07-07 | 1991-01-17 | Audi Ag | METHOD FOR PRODUCING WEAR-RESISTANT SURFACES ON COMPONENTS FROM AN ALUMINUM-SILICUM ALLOY |
| US5139585A (en) * | 1989-08-07 | 1992-08-18 | Honda Giken Kogyo Kabushiki Kaisha | Structural member made of titanium alloy having embedded beta phase of different densities and hard metals |
| US5001001A (en) * | 1989-09-25 | 1991-03-19 | The United States Of America As Represented By The Secretary Of Commerce | Process for the fabrication of ceramic monoliths by laser-assisted chemical vapor infiltration |
| DE3936479A1 (en) * | 1989-11-02 | 1991-05-08 | Guenter Link | Metallic and ceramic substrate coating method - using powder material applied to surface in liq. medium and melted by laser beam |
| GB2257163B (en) * | 1991-07-02 | 1995-04-05 | Res & Dev Min Def Gov In | A process for improving fatigue crack growth resistance |
| US5455079A (en) * | 1991-07-26 | 1995-10-03 | The United States Of America As Represented By The Secretary Of The Interior | Surface hardening of titanium alloys with melting depth controlled by heat sink |
| DE4205307C1 (en) * | 1992-02-21 | 1993-08-19 | Mercedes-Benz Aktiengesellschaft, 7000 Stuttgart, De | Partial surface-wear heat treatment of aluminium@ components of IC engines - by temporarily heating using high energy beam then cooling into deeper and adjoining regions |
| US5518820A (en) * | 1992-06-16 | 1996-05-21 | General Electric Company | Case-hardened titanium aluminide bearing |
| FR2698572B1 (en) * | 1992-11-27 | 1995-02-03 | Metallisation Ind Ste Nle | Method for recharging a part by means of a transferred arc plasma. |
| US5514849A (en) * | 1993-02-17 | 1996-05-07 | Electric Power Research Institute, Inc. | Rotating apparatus for repairing damaged tubes |
| US5430270A (en) * | 1993-02-17 | 1995-07-04 | Electric Power Research Institute, Inc. | Method and apparatus for repairing damaged tubes |
| US5653897A (en) * | 1993-02-17 | 1997-08-05 | Electric Power Research Institute | Rotating fiber optic coupler for high power laser welding applications |
| US5332422A (en) * | 1993-07-06 | 1994-07-26 | Ford Motor Company | Solid lubricant and hardenable steel coating system |
| US5427823A (en) * | 1993-08-31 | 1995-06-27 | American Research Corporation Of Virginia | Laser densification of glass ceramic coatings on carbon-carbon composite materials |
| US6139656A (en) * | 1995-07-10 | 2000-10-31 | Ford Global Technologies, Inc. | Electrochemical hardness modification of non-allotropic metal surfaces |
| JP2949414B2 (en) * | 1995-09-07 | 1999-09-13 | 株式会社河合楽器製作所 | Cladding material and its manufacturing method |
| US5889254A (en) * | 1995-11-22 | 1999-03-30 | General Electric Company | Method and apparatus for Nd: YAG hardsurfacing |
| IL124985A (en) * | 1996-01-15 | 2001-10-31 | Univ Tennessee Res Corp | Laser induced improvement of surfaces |
| US6350326B1 (en) | 1996-01-15 | 2002-02-26 | The University Of Tennessee Research Corporation | Method for practicing a feedback controlled laser induced surface modification |
| US5985056A (en) * | 1996-01-15 | 1999-11-16 | The University Of Tennessee Research Corporation | Method for laser induced improvement of surfaces |
| US5711826A (en) * | 1996-04-12 | 1998-01-27 | Crs Holdings, Inc. | Functionally gradient cladding for nuclear fuel rods |
| DE19632573A1 (en) * | 1996-08-13 | 1998-02-19 | Abb Patent Gmbh | Producing a contact unit for a vacuum chamber and resultant contact unit |
| US5897794A (en) * | 1997-01-30 | 1999-04-27 | The United States Of America As Represented By The Secretary Of The Navy | Method and apparatus for ablative bonding using a pulsed electron |
| US6599580B2 (en) | 1997-05-01 | 2003-07-29 | Wilson Greatbatch Ltd. | Method for improving electrical conductivity of a metal oxide layer on a substrate utilizing high energy beam mixing |
| US5947179A (en) * | 1998-07-30 | 1999-09-07 | Ford Motor Company | Sprayforming bulk deposits of allotropic metal |
| US6294225B1 (en) | 1999-05-10 | 2001-09-25 | The University Of Tennessee Research Corporation | Method for improving the wear and corrosion resistance of material transport trailer surfaces |
| US6299707B1 (en) | 1999-05-24 | 2001-10-09 | The University Of Tennessee Research Corporation | Method for increasing the wear resistance in an aluminum cylinder bore |
| US6173886B1 (en) | 1999-05-24 | 2001-01-16 | The University Of Tennessee Research Corportion | Method for joining dissimilar metals or alloys |
| US6497985B2 (en) * | 1999-06-09 | 2002-12-24 | University Of Tennessee Research Corporation | Method for marking steel and aluminum alloys |
| US6284067B1 (en) | 1999-07-02 | 2001-09-04 | The University Of Tennessee Research Corporation | Method for producing alloyed bands or strips on pistons for internal combustion engines |
| US6423162B1 (en) | 1999-07-02 | 2002-07-23 | The University Of Tennesse Research Corporation | Method for producing decorative appearing bumper surfaces |
| US6229111B1 (en) | 1999-10-13 | 2001-05-08 | The University Of Tennessee Research Corporation | Method for laser/plasma surface alloying |
| US6328026B1 (en) | 1999-10-13 | 2001-12-11 | The University Of Tennessee Research Corporation | Method for increasing wear resistance in an engine cylinder bore and improved automotive engine |
| SE9903780L (en) * | 1999-10-20 | 2001-04-21 | Duroc Ab | Process for making metal material articles and articles made by this method |
| DE19959378B4 (en) * | 1999-12-09 | 2005-03-03 | Mtu Aero Engines Gmbh | Coating process for magnesium alloy components |
| DE10043548C2 (en) * | 2000-08-14 | 2003-12-04 | Kochendoerfer & Kiep Metallver | Application of laser coating |
| DE10110756A1 (en) * | 2001-03-07 | 2002-09-19 | Bayerische Motoren Werke Ag | Heat treatment of hypereutectic Al-Si alloys |
| DE10124250C2 (en) * | 2001-05-18 | 2003-03-27 | Daimler Chrysler Ag | Method of forming a high strength and wear resistant composite layer |
| DE50308904D1 (en) * | 2002-07-30 | 2008-02-14 | Federal Mogul Nuernberg Gmbh | Method for producing a piston and piston |
| US7105205B2 (en) * | 2003-03-28 | 2006-09-12 | Research Foundation Of The State Of New York | Densification of thermal spray coatings |
| US20050092403A1 (en) * | 2003-10-29 | 2005-05-05 | Lloyd David J. | Functionally graded aluminum alloy sheet |
| DE10353474B4 (en) * | 2003-11-15 | 2007-02-22 | Daimlerchrysler Ag | Component of an internal combustion engine and method for its production |
| US7687151B2 (en) * | 2005-04-12 | 2010-03-30 | General Electric Company | Overlay for repairing spline and seal teeth of a mated component |
| US7591057B2 (en) * | 2005-04-12 | 2009-09-22 | General Electric Company | Method of repairing spline and seal teeth of a mated component |
| DE102005034905A1 (en) * | 2005-07-26 | 2007-02-01 | Federal-Mogul Nürnberg GmbH | Method for producing a piston for an internal combustion engine and pistons for an internal combustion engine |
| JP5101838B2 (en) * | 2006-05-16 | 2012-12-19 | ヤンマー株式会社 | Surface hardening method for metal members |
| NZ573913A (en) * | 2006-05-24 | 2012-03-30 | Bluescope Steel Ltd | Treating al/zn-based alloy coated products |
| DE102006046503A1 (en) * | 2006-08-18 | 2008-02-21 | Mg-Micro Galva Gmbh | Laser oxidation of magnesium, titanium or aluminum materials |
| FR2909298B1 (en) * | 2006-12-02 | 2009-07-10 | Technogenia Soc Par Actions Si | LASER RECHARGEABLE CONCAVE PIECE, METHOD AND DEVICE FOR REALIZING SAME |
| US20080304998A1 (en) * | 2007-06-05 | 2008-12-11 | Goodman Christopher R | Method of hardening titanium and titanium alloys |
| US8076605B2 (en) * | 2007-06-25 | 2011-12-13 | Electro Scientific Industries, Inc. | Systems and methods for adapting parameters to increase throughput during laser-based wafer processing |
| DE102008003871A1 (en) * | 2008-01-08 | 2009-07-09 | Volkswagen Ag | Finishing thin metal sheet and/or products made of thin metal sheets later designed as semifinished sheet metal products using laser beam technology, by locally melting surface of products with laser beam up to in given sheet-metal depth |
| US8927901B2 (en) * | 2008-03-17 | 2015-01-06 | Alcoa Inc. | Buried-arc welding of metal work pieces with through-the-arc seam tracking |
| DE102008019636A1 (en) * | 2008-04-18 | 2009-10-22 | Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. | Welded component and method for producing a weld |
| US20100279022A1 (en) * | 2009-05-04 | 2010-11-04 | Vetco Gray Inc. | System and Method For Applying A Coating To A Substrate |
| US20100297432A1 (en) * | 2009-05-22 | 2010-11-25 | Sherman Andrew J | Article and method of manufacturing related to nanocomposite overlays |
| MY179278A (en) | 2009-05-28 | 2020-11-03 | Bluescope Steel Ltd | Metal-coated steel strip |
| US8866044B2 (en) * | 2011-05-04 | 2014-10-21 | GM Global Technology Operations LLC | System and method for manufacturing magnesium body panels with improved corrosion resistance |
| US20140008339A1 (en) * | 2012-07-06 | 2014-01-09 | Lincoln Global, Inc. | Method and system for removing material from a cut-joint |
| KR101881708B1 (en) * | 2014-07-03 | 2018-07-24 | 신닛테츠스미킨 카부시키카이샤 | Laser machining device |
| DE102014222266A1 (en) * | 2014-10-31 | 2016-05-04 | Siemens Aktiengesellschaft | Remelting and subsequent build-up welding and component |
| JP6761596B2 (en) * | 2016-07-29 | 2020-09-30 | 三菱マテリアル株式会社 | Cutting tool made of composite material |
| FR3060609A1 (en) * | 2016-12-15 | 2018-06-22 | Airbus Operations Sas | SURFACE TREATMENT ON AN ALUMINUM ALLOY SUBSTRATE |
| JP7110907B2 (en) * | 2018-10-26 | 2022-08-02 | トヨタ自動車株式会社 | Lap welding method for dissimilar metal members |
| RU2749008C1 (en) * | 2020-08-31 | 2021-06-02 | Публичное Акционерное Общество "Новолипецкий металлургический комбинат" | Method for surface hardening for precipitation hardening steels |
Family Cites Families (19)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| IT559958A (en) * | 1955-07-06 | 1900-01-01 | ||
| US3802927A (en) * | 1970-09-14 | 1974-04-09 | N Gomada | Apex seal for rotary piston engine and method of producing same |
| DE2111183B2 (en) * | 1970-09-21 | 1978-03-23 | Vereinigte Edelstahlwerke Ag (Vew), Wien Niederlassung Vereinigte Edelstahlwerke Ag (Vew) Verkaufsniederlassung Buederich, 4005 Meerbusch | Process and arrangement for the two-stage surface hardening of workpieces made of hardenable iron and steel alloys |
| US3806380A (en) * | 1971-03-05 | 1974-04-23 | Hitachi Ltd | Method for hardening treatment of aluminum or aluminum-base alloy |
| GB1392812A (en) * | 1971-04-07 | 1975-04-30 | Atomic Energy Authority Uk | Methods for treating steel to modify the structure thereof |
| DE2134662A1 (en) * | 1971-07-12 | 1973-01-25 | Teves Thompson Gmbh | Strengthening metal parts - partic increasing the strength of valves in ic engines |
| US3839618A (en) * | 1972-01-03 | 1974-10-01 | Geotel Inc | Method and apparatus for effecting high-energy dynamic coating of substrates |
| US3850698A (en) * | 1972-06-23 | 1974-11-26 | Ind Materials Ltd | Altering material properties |
| DE2234206C2 (en) * | 1972-07-12 | 1973-12-20 | Mahle Gmbh, 7000 Stuttgart | Process for the production of a workpiece from light metal with finely distributed inclusions |
| JPS4942538A (en) * | 1972-08-30 | 1974-04-22 | ||
| JPS5010154A (en) * | 1973-05-24 | 1975-02-01 | ||
| US3872279A (en) * | 1973-10-24 | 1975-03-18 | Sirius Corp | Laser-radio frequency energy beam system |
| DE2362026A1 (en) * | 1973-12-13 | 1975-06-26 | Aluminium Werke Ag | Surface hardening of aluminium (alloys) - by applying a metal coating followed by a fusion treatment |
| CA1035675A (en) * | 1974-01-07 | 1978-08-01 | Avco Everett Research Laboratory | Formation of surface layer casings on articles |
| US4015100A (en) * | 1974-01-07 | 1977-03-29 | Avco Everett Research Laboratory, Inc. | Surface modification |
| US3944443A (en) * | 1974-05-01 | 1976-03-16 | Francis Lee Jones | Ultra high temperature chemical reactions with metals |
| GB1493394A (en) * | 1974-06-07 | 1977-11-30 | Nat Res Dev | Plasma heater assembly |
| US3992164A (en) * | 1974-09-16 | 1976-11-16 | Fengler Werner H | High-wear resistant composite seal |
| US3952180A (en) * | 1974-12-04 | 1976-04-20 | Avco Everett Research Laboratory, Inc. | Cladding |
-
1976
- 1976-09-13 US US05/722,965 patent/US4157923A/en not_active Expired - Lifetime
-
1977
- 1977-06-28 CA CA281,514A patent/CA1093433A/en not_active Expired
- 1977-07-11 IT IT50228/77A patent/IT1079283B/en active
- 1977-08-23 JP JP52100210A patent/JPS6037176B2/en not_active Expired
- 1977-08-26 GB GB36045/77A patent/GB1587235A/en not_active Expired
- 1977-09-06 ES ES462164A patent/ES462164A1/en not_active Expired
- 1977-09-08 DE DE2740569A patent/DE2740569B2/en not_active Ceased
- 1977-09-13 FR FR7727611A patent/FR2371520A1/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6037176B2 (en) | 1985-08-24 |
| US4157923A (en) | 1979-06-12 |
| DE2740569A1 (en) | 1978-03-16 |
| GB1587235A (en) | 1981-04-01 |
| JPS5334618A (en) | 1978-03-31 |
| ES462164A1 (en) | 1978-12-16 |
| FR2371520B1 (en) | 1980-08-01 |
| DE2740569B2 (en) | 1981-01-29 |
| IT1079283B (en) | 1985-05-08 |
| FR2371520A1 (en) | 1978-06-16 |
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