Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.

Patents

  1. Advanced Patent Search
Publication numberUS3150938 A
Publication typeGrant
Publication dateSep 29, 1964
Filing dateJun 9, 1960
Priority dateJun 9, 1960
Publication numberUS 3150938 A, US 3150938A, US-A-3150938, US3150938 A, US3150938A
InventorsJohn F Pelton, Jr John M Koffskey
Original AssigneeUnion Carbide Corp
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Coating composition, method of application, and product thereof
US 3150938 A
Abstract  available in
Images(1)
Previous page
Next page
Claims  available in
Description  (OCR text may contain errors)

' J. F. PELTON ETAL 3,350,938 comma COMPOSITION METHOD OF APPLICATION AND PRODUCT THEREOF Filed June 9. 1960 Sept. 29 1964 INVENTORS JOHN, F .PELTON JOHN M.KOFFSKEY,JR.

M PM A TTORNE) United States Patent "ice v 3,150,938 COATING COMPOSITION, METHOD OF APPLI- CATION, AND PRODUCT THEREQF John F. Pelton and John M. Kotiskey, 51a, Indianapolis,

Ind., assignors to Union Carbide Corporation, a corporation of New York Y Filed June 9, 1960, Ser. No. 34,871 Claims. (Cl. 29-494) This invention relates to a specific coating composition,

to a method for applying same, and to the coated article so obtained. More particularly, it relates to such a composition capable of producing a coating having excellent high temperature wear and oxidation resistance. 1 There is a need in industry for coating materials that can withstand severe wear conditions at high temperatures. In particular, the aircraft industry requires coatings to protect wear surfaces in turbo-jet engines. The turbine blades, for example, undergo some distortion due to temperature expansion and contraction as well as to high velocity conditions. This distortion creates severe wear conditions on the contact surfaces between turbine blade spacers. Prior wear resistant coating materials, such as tungsten carbide with cobalt binder, have been unable to give adequate protection in this area. The prior coatings could not stand up under the high temperature wear and oxidizing conditions. An aluminum oxide coating, for example, is able to withstand the high temperature oxidizing conditions but its Wear resistance is not quite high enough, especially when mating with itself. It also is too brittle and does not have sufiicient bond strength.

It is accordingly the object of the present invention to provide a powder composition suitable for application by flame-plating techniques which result in coatings having good resistance at high temperatures to wear and oxidation.

The sole figure in the drawing is a photomicrograph at 500 diameter magnification showing the base material with the wear and oxidization resistant coating bonded thereto.

The objects of this invention are accomplished in general by a coating composition which comprises between about 70 and 90 weight percent chromium carbide (Cr C and lower carbides) and between about 30 and weight percent of a nickel-chromium alloy (80 percent nickel-20 percent chromium). This material can be applied as a coating to various base materials by means of the detonation plating process disclosed in United States Patent No. 2,714,563 or by other high temperature high velocity coating processes, such as the arc torch or jet burner disclosed in application Serial No. 706,099 and now abandoned, filed December 30, 1957, by Gage et al., and in Patent No. 2,861,900, filed May 2, 1955, by G. H. Smith et al. The actual composition of the resulting coating will be somewhat dilferent from the above starting composition due to changes brought about by heating during the coating process. For example, the coatings of this material applied by the detonation process, when using a starting composition of about 85 Weight percent chromium carbide and about weight percent of a nickelchromium alloy (80 percent Nipercent Cr) and an oxygen/carbon atomic ratio of 1.2 and nitrogen dilution of 46 volume percent have a general composition of about 10 weight percent Cr C 15 weight percent nickelchromium alloy, and the remainder 'a mixture of chromium carbides, chromium oxides, and chromium metal.

The advantages of these new coating compositions in resisting wear are shown in the following table which contpares relative wear of several coating combinations under high temperature high load conditions. These tests were run to determine the resistance to gross wear caused by galling and scoring. Test conditions were: 500 p.s.i.g. pressure on samples; relative rubbing speed between the 3,150,938 Patented fiept. 29, 1964 TABLE I 7 Comparative Wear for Combinations of Coatings in Mating Relation Loss in Temper- Coating ature at Thickness Test Piece l0- i1nehes/ Mating Materials 7. 2 CrsCz-(Ni-Cr) 7. 6 OraCz-(Ni-Or).. 1, 300 8.2 203 5. 3

3 WC-CraCz-Nll, 300 36 It can be seen from the above table that prior coating combinations of aluminum oxide, tungsten carbide-cobalt, and tungsten carbide-chromium carbide-nickel have excessive total wear at high temperatures and high load. The novel coating of the present invention has comparatively low total wear when mating with aluminum oxide and especially when mating with itself. This last property is quite important since it is most desirable to coat similar mating surfaces with the same material to simplify fabrication and replacement procedures.

This novel coatinghas also withstood severe oxidizing conditions up to at least 1800 F. without failure. Prior wear resistant coatings, such as tungsten carbide-cobalt fail due to oxidation above 1000 F.

The coating starting material is usually prepared by blending chromium carbide and nickel-chromium alloy powders of desired size suitable for coating (about 325 mesh and finer). A chromium and nickel powder mixture could be sustituted for the nickel-chromium alloy. The particular method of powder preparation used would depend primarily upon economic factors, such as availability of particular raw materials.

The following examples describe the application of this novel coating composition to a baseplate by the detonation plating process.

EXAMPLE I.APPLICATION OF AN 85 PERCENT CHRO- MIUM CARBIDE 15 PERCENT NICKEL-CHROMIUM ALLOY COATING Acetylene at 1.5 c.f.m., oxygen at 1.8 c.f.m., and nitrogen at 2.2 c.f.m. were introduced to a detonation gun to form a detonable mixture having an oxygen/ carbon atomic ratio of 1.2. Finely divided coating powder having a composition of 85 weight percent chromium carbide and 15 weight percent nickel-chromium alloy (80 percent nickel-20 percent chromium) suspended in a nitrogen carrier gas stream of 0.6 c.f.m. was introduced at a rate of 30-32 gram/min. to the barrel of the detonation gun. The detonable mixture thus surrounding the coating particles contained about 46 volume percent nitrogen. The detonation mixture was ignited at a rate of about four times per second and the coating powder was impinged on a metal baseplate to form a dense adherent coating composed of irregular shaped microscopic leaves interlocking and overlapping with each other. The coating has an average hardness of 800-850 VPN as measured with a 300 gram load and a modulus of rupture of 75,000 p.s.i.

EXAMPLE II.APPLICATION OF A PERCENT CHRO- MIUM CARBIDE 25 PERCENT NICKEL-CHROMIUM ALLOY COATING Acetylene at 1.13 c.f.m., oxygen at 1.35 c.f.m. and nitrogen at 3.02 c.f.m. were introduced to a detonation gun to form a detonatabie mixture having an oxygen/carbon atomic ratio of 1.2. Finely divided coating powder having a composition of 75 weight percent chromium carbide and 25 weight percent nickel-chromium alloy (80 percent nickel-20 percent chromium) suspended in a nitrogen carrier gas stream of 0.6 c.f.m. was introduced at a rate of 32 grams per minute to the barrel of the detonation gun. The detonatable mixture thus surrounding the coating particles contained about 60 volume percent nitrogen. The detonatable mixture was ignited at a rate of about four times per second, and the coating powder was impinged on a metal baseplate to form a dense adherent coating about 0.0050.096 inch thick composed of irregular shaped microscopic leaves interlocking and overlapping with each other. The coating had an average hardness of 775-825 VPN as measured with a 300 gram load. The coating has a modulus of rupture of about 82,000 psi. The final coating product has a general composition of about 30 weight percent Cr C 30 weight percent nickel-chromium alloy, and the remainder a mixture of chromium carbides, chromium oxides and chromium metal.

It is noted that the above Example II employed a nitrogen content of about 60 volume percent in the detonation gun barrel. This is the preferred operating condition for applying the high binder content composition on turbine blades since the resulting lower flame temperature aids in retaining an increased amount of binder in the coating product. The high binder content composition of the latter example results in a more impact resistant coating and also in a higher modulus of rupture and would be used for applications where those qualities were of paramount importance.

The above examples illustrate the use of the instant novel coating compositions with a detonation gun; however, it should be reiterated that the said compositions can be used with equal success with other flame-plating processes such as the arc torch and the jet burner. The specific coating composition ratios by weight of chromium carbide, chromium, and nickel disclosed represent a definite advance in the art of coatings which have high temperature wear and oxidation resistance.

It is to be understood that the novel coating composition may contain between about 70-90 weight percent chromium carbide and between about 3() weight percent of a nickel-chromium alloy (80 percent nickel-20 percent chromium) without affecting the utility of the coating as disclosed. However, the ratios set forth in xi. the above examples represent the preferred embodiments.

This application is a continuation-in-part application of our application Serial No. 738,299, filed May 28, 1958, and now abandoned.

What is claimed is:

1. A coating composition which comprises between about and 90 percent by weight of powdered chromium carbide, between about 8 and 24 percent by weight of powdered nickel and the remainder being powdered chromium.

2. A coating composition which comprises about 85 percent by weight of powdered chromium carbide, 12 percent by weight of powdered nickel and the remainder being powdered chromium.

3. A coating composition which comprises about percent by weight of powdered chromium carbide, 20 percent by weight of powdered nickel and 5 percent by weight of powdered chromium.

4. A method of applying a high temperature wear and oxidation resistant coating which comprises introducing a finely divided powder comprising about 75 percent by weight of powdered chromium carbide, about 20 percent by weight of powdered nickel and about 5 percent by weight of powdered chromium into a detonation gun, surrounding such composition with a detonable fuelc-xidant mixture having an oxygen/ carbon atomic ratio of about 1.2 and containing about 60 volume percent nitrogen; igniting such detonable mixture to form a detonation, and impinging the coating composition onto a body to be coated by means of the high temperature high velocity gas stream and shock wave attendant with such detonation.

5. An article of manufacture made according to claim 4 wherein the coating in such body has a lamellar structure of interlocking and overlapping microscopic leaves bonded to each other and to said body.

References Cited in the file of this patent UNITED STATES PATENTS 2,067,166 Balke Jan. 12, 1937 2,128,146 Hinnuber Aug. 23, 1938 2,581,252 Goetzel et al. Jan. 1, 1952 2,714,563 Poorman et al. Aug. 2, 1955 2,753,621 Wellborn July 10, 1956 FOREIGN PATENTS 318,524 Switzerland Feb. 28, 1957

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2067166 *Mar 6, 1933Jan 12, 1937Ramet CorpTantalum carbide alloy
US2128146 *Jul 7, 1936Aug 23, 1938Gen ElectricSintered hard metal alloys
US2581252 *Dec 31, 1947Jan 1, 1952Sintercast Corp AmericaPowder metallurgy articles
US2714563 *Mar 7, 1952Aug 2, 1955Union Carbide & Carbon CorpMethod and apparatus utilizing detonation waves for spraying and other purposes
US2753621 *Feb 11, 1953Jul 10, 1956Firth Sterling IncSintered carbide compositions and method of making the same
CH318524A * Title not available
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3230097 *May 31, 1962Jan 18, 1966Gen ElectricCoating composition
US3473943 *Dec 18, 1967Oct 21, 1969Asahi Chemical IndExplosive coating of metallic substrates with powder
US3881910 *Aug 15, 1973May 6, 1975Union Carbide CorpChromium-chromium carbide powder
US3941903 *Nov 17, 1972Mar 2, 1976Union Carbide CorporationWear-resistant bearing material and a process for making it
US4075376 *Apr 1, 1976Feb 21, 1978Eutectic CorporationBoiler tube coating and method for applying the same
US4163071 *Jul 5, 1977Jul 31, 1979Union Carbide CorpMethod for forming hard wear-resistant coatings
US4275090 *Oct 15, 1979Jun 23, 1981United Technologies CorporationProcess for carbon bearing MCrAlY coating
US4275124 *Oct 15, 1979Jun 23, 1981United Technologies CorporationCarbon bearing MCrAlY coating
US4334927 *Dec 8, 1980Jun 15, 1982Hyde Glenn FPiston ring coatings
US4471008 *Aug 2, 1982Sep 11, 1984Mtu Motoren-Und-Turbinen Union Munchen GmbhMetal intermediate layer and method of making it
US4606948 *May 20, 1985Aug 19, 1986Sherritt Gordon Mines LimitedProcess for the production of nickel-chromium/chromium carbide coatings on substrates
US4826734 *Mar 3, 1988May 2, 1989Union Carbide CorporationTungsten carbide-cobalt coatings for various articles
US4902539 *Feb 4, 1988Feb 20, 1990Union Carbide CorporationFuel-oxidant mixture for detonation gun flame-plating
US4999255 *Nov 27, 1989Mar 12, 1991Union Carbide Coatings Service Technology CorporationTungsten chromium carbide-nickel coatings for various articles
US5006371 *Mar 8, 1990Apr 9, 1991Air Products And Chemicals, Inc.Low temperature chemical vapor deposition method for forming tungsten and tungsten carbide
US5024901 *May 3, 1989Jun 18, 1991Air Products And Chemicals, Inc.Method for depositing highly erosive and abrasive wear resistant composite coating system on a substrate
US5075129 *Nov 30, 1990Dec 24, 1991Union Carbide Coatings Service Technology CorporationMethod of producing tungsten chromium carbide-nickel coatings having particles containing three times by weight more chromium than tungsten
US5137422 *Oct 18, 1990Aug 11, 1992Union Carbide Coatings Service Technology CorporationProcess for producing chromium carbide-nickel base age hardenable alloy coatings and coated articles so produced
US5223332 *May 31, 1990Jun 29, 1993Praxair S.T. Technology, Inc.Duplex coatings for various substrates
US5419976 *Dec 8, 1993May 30, 1995Dulin; Bruce E.Thermal spray powder of tungsten carbide and chromium carbide
US5839880 *Jul 18, 1995Nov 24, 1998Hitachi, Ltd.Bearing unit, drainage pump and hydraulic turbine each incorporating the bearing unit, and method of manufacturing the bearing unit
US5906896 *Jul 21, 1992May 25, 1999Praxair S.T. Technology, Inc.Rotary seal member coated with a chromium carbide-age hardenable nickel base alloy
US20090208662 *Apr 30, 2009Aug 20, 2009United Technologies CorporationMethods for Repairing a Workpiece
DE1671130B1 *Jan 8, 1966May 25, 1972Union Carbide CorpVerfahren zur herstellung von ueberzuegen
DE2603640A1 *Jan 30, 1976Aug 5, 1976Union Carbide CorpZweischichtueberzug
WO1983001917A1 *Nov 22, 1982Jun 9, 1983Gte Prod CorpNickel-chromium carbide powder and sintering method
Classifications
U.S. Classification428/564, 106/1.27, 427/180, 148/22, 428/937, 75/229, 75/240, 427/451, 428/686, 428/940, 75/252, 427/427, 427/249.17, 428/938, 427/600, 427/422
International ClassificationC23C4/06, C22C29/00
Cooperative ClassificationY10S428/94, C23C4/06, Y10S428/938, Y10S428/937, C22C29/00
European ClassificationC22C29/00, C23C4/06