Claims
- 1. A hard drive disk substrate comprised of an aluminum-boron-carbon composite, the composite having from about four volume percent to about thirty volume percent of free aluminum metal, the composite having a density greater than ninety eight percent of theoretical density wherein the substrate is formed by a process that melts the aluminum.
- 2. A hard drive disk substrate comprised of an aluminum-boron-carbon composite, the composite having from about four volume percent to about fifteen volume percent of free aluminum metal, the composite having a density greater than ninety eight percent of theoretical density wherein the substrate is formed by a process that melts the aluminum.
- 3. The hard drive disk substrate of claim 1 having a nickel-containing layer thereon.
- 4. The hard drive disk substrate of claim 1 having a nickel-containing layer thereon and a magnetic media layer deposited on the nickel-containing layer.
- 5. The hard drive disk substrate of claim 1, wherein the composite includes at least three ceramic phases other than B.sub.4 C as well as the phases B.sub.4 C and Al.
- 6. The hard drive disk substrate of claim 5, wherein the substrate has a layer of metal thereon and a transition zone between the substrate and the layer of metal, the transition zone comprising a composite of the B.sub.4 C and the metal.
- 7. The hard drive disk substrate of claim 1, wherein the composite comprises aluminum and a continuous ceramic network of boron carbide grains, aluminum-boron phase and aluminum-boron-carbon phase.
- 8. The hard drive disk substrate of claim 7, wherein most of the aluminum is in the intersticies of the boron carbide grains, the aluminum-boron phase and the aluminum-boron-carbon phase.
- 9. The hard drive disk substrate of claim 7 having a nickel-containing layer thereon.
- 10. The hard drive disk substrate of claim 2 having a nickel-containing layer thereon and a magnetic media layer deposited on the nickel-containing layer.
- 11. The hard drive disk substrate of claim 2, wherein the composite includes at least three ceramic phases other than B.sub.4 C as well as the phases B.sub.4 C and Al.
- 12. The hard drive disk substrate of claim 11, wherein the substrate has a layer of metal thereon and a transition zone between the substrate and the layer of metal, the transition zone comprising a composite of the B.sub.4 C and the metal.
- 13. The hard drive disk substrate of claim 2, wherein the composite comprises aluminum and a continuous ceramic network of boron carbide grains, aluminum-boron phase and aluminum-boron-carbon phase.
- 14. The hard drive disk substrate of claim 13, wherein most of the aluminum is in the intersticies of the boron carbide grains, the aluminum-boron phase and the aluminum-boron-carbon phase.
- 15. The hard drive substrate of claim 1, wherein the composite has a density of about 2.58 to about 2.7 g/cc and an elastic modulus of at least about 220 GPa.
- 16. The hard drive substrate of claim 15 wherein the composite has a fracture toughness of at least about 4 MPam.sup.1/2.
- 17. The hard drive substrate of claim 1 wherein the composite consists essentially of the reaction product of boron carbide powder and aluminum.
- 18. The hard drive substrate of claim 17 wherein the composite contains B.sub.4 C, free aluminum metal and at least three reaction products selected from the group consisting of AlB.sub.24 C.sub.4, Al .sub.3-4 BC, AlB.sub.2, AlB.sub.12, AlB,.sub.12 C.sub.2 and Al.sub.4 B .sub.1-3 C.sub.4.
- 19. The hard drive substrate of claim 2, wherein the composite has a density of about 2.58 to about 2.7 g/cc and an elastic modulus of at least about 220 GPa.
- 20. The hard drive substrate of claim 19 wherein the composite has a fracture toughness of at least about 4 MPam.sup.1/2.
- 21. The hard drive substrate of claim 2 wherein the composite consists essentially of the reaction product of boron carbide powder and aluminum.
- 22. The hard drive substrate of claim 21 wherein the composite contains B.sub.4 C, free aluminum metal and at least three reaction products selected from the group consisting of AlB.sub.24 C.sub.4, Al.sub.3-4 BC, AlB.sub.2, AlB.sub.12, AlB.sub.12 C.sub.2, and Al.sub.4 B.sub.1-3 C.sub.4.
Parent Case Info
This application is a divisional of application Ser. No. 08/496,798, filed Jun. 29, 1995, now abandoned which is a continuation-in-part application Ser. No. 08/354,185 filed on Dec. 12, 1994, now abandoned.
US Referenced Citations (26)
Foreign Referenced Citations (3)
Number |
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0322336 |
May 1993 |
EPX |
0299905 |
Jun 1993 |
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0378504 |
Aug 1994 |
EPX |
Divisions (1)
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Number |
Date |
Country |
Parent |
496798 |
Jun 1995 |
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Continuation in Parts (1)
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Number |
Date |
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Parent |
354185 |
Dec 1994 |
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