Claims
- 1. A method of coating a ceramic onto a substrate, comprising:
selecting said substrate having a top surface; supplying said ceramic having a bottom surface; coating said ceramic onto a selected area on said top surface of said substrate; furnishing at the contact area between said ceramic and said substrate a bonding substance containing a carbide-forming metal which chemically reacts with said ceramic, above a first temperature of below 1500° C., to form a metal carbide capable of bonding to both said ceremic and said substrate, said carbide-forming metal being selected from the group consisting of Au, B, Ir, La, Li, Mn, Mo, Os, Re, Rh, Ru, Si, Th, U, V, W, and mixtures or alloys thereof; and without pressurizing said ceramic and said substrate heating said coated ceramic in contact with said substrate above said first temperature to cause said chemical reaction to occur thereby forming a first bonding layer microscopically substantially perfectly bonding said ceramic to said selected surface of said substrate; said first bonding bonding layer being void-free and microcrak-free and from 100 Angstroms to 0.375 mm thick, and comprising essentially of said metal carbide.
- 2. A method as in claim 1 including the additional steps of:
(A) mixing said carbide forming metal, a braze which alloys with said metal, and a temporary binder to provide a coating material; (B) applying said coating material and a layer of said ceramic to said substrate; and (C) heating the product of step (B) above said first temperature to initially form a carbide coating on said ceramic and thereafter to braze said carbide coated ceramic to said substrate.
- 3. A method as in claim 2 wherein said braze comprises a metal selected from the group consisting of Ag, Al, Au, Bi, Cd, Co, Cr, Cu, Fe, Ga, In, Mg, Mn, Ni, Pb, Sb, Sn, Pt, Pd, Ti, Zn, compounds of these metals, and mixtures or combinations thereof; and
said ceramic is selected from the group consisting of alumina, boron carbide, boron nitride, diamond, boron carbide, silicon carbide, silicon nitride, titanium boride, titanium carbide, zirconia, zirconium carbide.
- 4. A method as in claim 2 wherein said furnishing step comprises furnishing said bonding substance containing said carbide-forming metal which forms said metal carbide capable of directly bonding, without braze, compliant, or other intermediate layer, to both said ceramic and said substrate.
- 5. A method as in claim 2 wherein said mixing step comprises controlling the sizes and gravitational segregation of said mixed powders in the temporary binder to achieve a substantially uniform composition of said element carbide coating at a specified distance from the surface of said substrate.
- 6. A method of claim 2 wherein:
said ceramic is diamond; said substrate is selected from the group consisting of Ag, AlN, Au, C, BeO, Fe, graphite, Mo, Ni, Pt, Si, SiC, diamond, silicon nitride, Al, Co, Cr, Cu, Ir, Mn, Os, Rd, Rh, V, W, steel, alumina, boron carbide, boron nitride, silicon oxide, tungsten carbide, ceramic superconductors, thermally conductive composite, and a combination thereof; and said furnishing and heating steps comprise providing said first bonding layer to consist mostly of a single braze metal selected from the group consisting of copper, silver, aluminum, and gold.
- 7. A method as in claim 1 wherein the carbide-forming metal is selected from the group consisting of Si, Mo, W, and Fe.
- 8. A method as in claim 1 wherein sid carbide-forming metal and said substrate are of the same metal element selected from the group consisting of Mo, Si, Fe, and W.
- 9. A method as in claim 1 wherein said substrate and said carbide-forming metal are of the same single metal element selected from the group consisting of Mo, Si, Fe, and W.
- 10. A method as in claim 1 wherein said carbide-forming metal consists essentially of a single metal selected from the group consisting of Au, B, Fe, Ir, La, Li, Mn, Mo, Os, Re, Rh, Ru, Si, Th, U, V, and W.
- 11. A method as in claim 1 wherein said heating step comprises heating said ceramic and said substrate together in a gaseous environment comprising essentially of a gas selected from the group consisting of hydrogen, nitrogen, hydrocarbon gas, and mixtures thereof.
- 12. A method as in claim 1 wherein said furnishing and heating steps comprise providing on said diamond body said first bonding layer having a thickness of no more than 1,000 Angstroms and containing no microcarcks.
- 13. A method as in claim 1 wherein said heating step comprises heating to form said metal carbide on said ceramic and to melt at least part of said metal carbide thereby forming a melted and re-solidified, first bottom bonding layer for bonding said ceramic onto said substrate.
- 14. A method as in claim 13 wherein said ceramic contains in the surface region thereof surface defects; and
wherein maid furnishing step comprises preparing a wettable metal carbide when it melts above said first temperature; at least partially melting said wettable metal carbide; allowing said molten, wettable metal carbide to penetrate into said ceramic surface region particularly into said surface defects contained therein thereby sealing at least one of said ceramic surface defects; and solidifying said molten metal carbide to provide a solid strengthener in said ceramic.
- 15. A method of coating ceramic onto a substrate, comprising:
supplying said ceramic; selecting said substrate to consist essentially of a single metal element selected from the group consisting of Au, B, Fe, Ge, Hf, Ir, La, Li, Mn, Mo, Os, Pd, Re, Rh, Ru, Si, Th, Ur V, and W; without external pressure on said ceramic, said single metal element being capable of chemically reacting, above a first temperature, with said ceramic to produce between said ceramic and said substrate, a void-free and microcrack-free interfacial bonding material of up to 0.375 mm thick and comprising essentially of said eutectic, said bonding material being capable of directly bonding, microscopically substantially perfectly, to both said ceramic powders and said substrate; and causing, at a second temperature sufficiently higher than said first temperature but without the external pressure, said chemical reaction between said ceramic and said single metal element substrate to take place in order to produce said eutectic interfacial bonding material layer to allow said ceramic to be coated and bonded onto said substrate for withstanding temperatures above 630° C.
- 16. A method as in claim 15 wherein said selecting step comprises selecting said single metal element which is capable of forming, at said second temperature of less than 1350° C., a carbide with said ceramic, said eutectic comprising essentially of the thus formed carbide.
- 17. A method as in claim 15 wherein said supplying step comprises supplying said ceramic having a bottom surface;
said selecting step comprises selecting the substrate to have a top surface; said causing step comprises coating said top surface of said substrate with said ceramic; and said heating step comprises heating together said ceramic-coated substrate to produce said interfacial bonding material layer directly bonding and coating said ceramic onto said said top surface of said substrate.
- 18. A method as in claim 15 whereinsaid said heating step comprises heating said ceramic-coated substrate in a gaseous reducing environment comprising a hydrocarbon gas.
- 19. A method as in claim 15 wherein said heating step comprises heating said ceramic-coated substrate in a gaseous environment comprising a gas selected from the group consisting of hydrogen, nitrogen, hydrocarbon gas, and mixtures thereof.
- 20. A method as in claim 15 wherein said gaseous environment is selected from the group consisting of at least one hydrogen-containing gas, at least one carbon-containing gas, and a mixture thereof.
- 21. A method as in claim 15 wherein said single metal element is selected from the group consisting of Mo, Si, Fe, and W.
- 22. A method as in claim 15 wherein said ceramic is selected from the group consisting of AlN, C, diamond, BeO, graphite, Si, SiC, silicon nitride, boron carbide, boron nitride, alumina, zirconia, titanium boride, titanium carbide, zirconium carbide, tungsten carbide, thermally conductive composite, and a combination thereof.
- 23. A method of making a ceramic coated product comprising a ceramic coated and bonded onto a substrate, comprising:
selecting said substrate having a top surface; supplying said ceramic having a bottom surface; positioning said ceramic to have at least a part of said bottom surface in contact with said top surface of said substrate; furnishing at the contact area between said ceramic and said substrate a bonding substance containing a material which chemically reacts above a first temperature with said ceramic to form a chemical composition capable of forming microscopically substantially perfectly coated layer of said ceramic on said substrate; heating said ceramic in contact with said substrate above said first temperature to cause said chemical reaction to occur thereby forming a bonding layer of said chemical composition which microscopically substantially perfectly bonds said top surface of said substrate to said bottom surface of said ceramic; and controlling the thickness of said bonding layer to an accuracy of less than 100 Angstroms.
- 24. A method as in claim 23 wherein said controlling step comprises controlling the thickness of said bonding layer to an accuracy of less than 10 Angstroms.
- 25. A method as in claim 23 including the additional step of:
providing in said bonding layer a stress-suppressing substance which divides said bonding layer into a plurality of bonding regions to thereby minimize the transmission of mismatch stress between said ceramic and said substrate from one of said bonding regions to another.
- 26. A method as in claim 23 wherein said ceramic coated product is capable of withstanding loads for practical uses above 630° C.; and
wherein said bonding layer is either macroscopically or microscopically void-free and crack-free.
- 27. A method as in claim 23 wherein:
said heating step comprises heating, without pressurizing said ceramic, in a gaseous environment selected from the group consisting essentially of at least one hydrogen-containing gas, at least one carbon-containing gas, and a mixture thereof; said ceramic is diamond or silicon carbide; both said substrate and said bonding substance consist essentially of a single metal selected from the group consisting of Fe, Si, Mo, and W; and said first temperature is less than 1,350° C.
- 28. A method as in claim 23 wherein said heating step is a single-step heating process; and
wherein said substrate is a material selected from the group consisting of a metal and a ceramic.
- 29. A method as in claim 23 wherein said ceramic is selected from the group consisting of diamond, carbon, graphite, silicon carbide, silicon nitride, ceramic superconductor, and composite containing one of more of these ceramics; and
wherein said substrate is selected from the group consisting of Ag, Al, Au, C, Co, Cr, Cu, Fe, Ir, Mn, Mo, Ni, Os, Rd, Rh, Si, V, W, steel, graphite, diamond, alumina, aluminum nitride, boron carbide, boron nitride, silicon carbide, silicon nitride, silicon oxide, tungsten carbide, [insulators,] and ceramic superconductor.
- 30. A method as in claim 23 wherein said ceramic is diamond or silicon carbide;
said substrate is selected from the group consisting of Fe, Mo, Si, W, silicon carbide, and ceramic superconductor; and said bonding layer is controlled to within 100 Angstroms in thickness.
REFERENCE TO RELATED APPLICATIONS
[0001] This is a continuation-in-part (CIP) of my pending U.S. application Ser. No. 08/301,582, filed Sep. 7, 1994; which is a CIP of U.S. application Ser. No. 08/123,877, filed Sep. 20, 1993. The 123,877 application is a CIP of pending applications Ser. Nos. 07/804,287; 07/804,285; and 07/244,421; respectively filed Dec. 9, 1991, Dec. 9, 1991, and Sep. 16, 1988, the later two now U.S. Pat. Nos. 5,248,079 and 5,230,924, respectively. The 804,285 application is CIP of my pending application Ser. No. 07/499,707, filed Mar. 27, 1990, now U.S. Pat. No. 5,161,728. Both the 499,707 and 244,421 applications are CIP's of my U.S. pending application Ser. No. 07/277,672, filed Dec. 14, 1988, now abandoned U.S. Pat. No. 5,000,986. The 499,707 and application is a CIP of Ser. No. 07/277,666, filed Nov. 29, 1988, now U.S. Pat. No. 4,890,783. I hereby incorporate by reference all of the above-cited references.
Continuation in Parts (7)
|
Number |
Date |
Country |
Parent |
08301582 |
Sep 1994 |
US |
Child |
08482199 |
Jun 1995 |
US |
Parent |
08123877 |
Sep 1993 |
US |
Child |
08301582 |
Sep 1994 |
US |
Parent |
07804287 |
Dec 1991 |
US |
Child |
08123877 |
Sep 1993 |
US |
Parent |
07804285 |
Dec 1991 |
US |
Child |
08123877 |
Sep 1993 |
US |
Parent |
07244421 |
Sep 1988 |
US |
Child |
08123877 |
Sep 1993 |
US |
Parent |
07277672 |
Dec 1988 |
US |
Child |
07499707 |
Mar 1990 |
US |
Parent |
07277666 |
Nov 1988 |
US |
Child |
07499707 |
Mar 1990 |
US |