Claims
- 1. A cutting tool insert consisting essentially of a ceramic composition comprising
- a polycrystalline alumina matrix,
- 10 to 50 volume percent single crystal titanium carbide whiskers distributed within said alumina matrix, and
- a residue of sintering aids up to 3 volume percent.
- 2. The cutting tool insert according to claim 1 wherein the alumina matrix is comprised of at least 99 weight percent Al.sub.2 O.sub.3 and the residue of sintering aids comprises ZrO.sub.2, CaO, MgO, or Y.sub.2 O.sub.3.
- 3. The cutting tool insert according to claim 2 wherein the alumina matrix comprises a high purity alumina matrix having an average grain size from about 0.5 to 3 microns and the whiskers have a length ranging up to 150 microns.
- 4. The cutting tool insert according to claim 1 wherein the ceramic composition comprises:
- 65 to 85 volume percent high purity, alumina,
- 15 to 35 volume percent titanium carbide whiskers, and
- a residue of sintering aids up to 1.5 volume percent.
- 5. The cutting tool insert according to claim 1 wherein the ceramic composition comprises:
- 75 to 85 volume percent high purity alumina,
- 25 to 35 volume percent titanium carbide whiskers, and
- a residue of sintering aids up to 1.5 volume percent.
- 6. The cutting tool insert according to claim 1 wherein the whiskers are randomly oriented.
- 7. The cutting tool insert according to claim 1 wherein the whiskers are oriented in planes perpendicular to one axis.
- 8. A method of machining steels, cast iron or superalloys comprising the steps of:
- (a) using a cutting tool insert consisting essentially of of sintered ceramic composition comprising a polycrystalline alumina matrix having titanium carbide whiskers distributed therein and
- (b) maintaining the machining feed rate between 0.005 and 0.030 inch per revolution and the machining speed between 500 and 4000 surface feet per minute.
- 9. The method according to claim 8 further comprising a depth of cut ranging up to 0.2 inch.
- 10. The method according to claim 8 wherein said composition of said cutting tool insert comprises:
- 50 to 90 volume percent high purity alumina,
- 10 to 50 volume percent single crystal titanium carbide whiskers, and
- a residue of sintering aids up to 3 volume percent.
- 11. The method according to claim 10 wherein the high purity alumina of the composition of the cutting tool insert is comprised of at least 99 weight percent Al.sub.2 O.sub.3 and the residue of sintering aids comprises ZrO.sub.2, CaO, MgO, or Y.sub.2 O.sub.3.
- 12. The method according to claim 10 wherein the average grain size of the high purity alumina matrix of the composition of the cutting tool insert is 0.5 to 3 microns and the diameter of the titanium carbide whiskers ranges from 0.25 to 3 microns and the length of the whiskers ranges up to 150 microns.
- 13. The method according to claim 8 wherein said composition of said cutting tool insert comprises:
- 65 to 85 volume percent high purity alumina,
- 15 to 35 volume percent titanium carbide whiskers, and
- a residue of sintering aids up to 1.5 volume percent.
- 14. The method according to claim 8 wherein said composition of said cutting tool insert comprises:
- 75 to 85 volume percent high purity alumina and
- 25 to 35 volume percent titanium carbide whiskers.
- 15. The method according to claim 10 wherein the whiskers in the composition of the cutting tool insert are randomly oriented.
- 16. The method according to claim 10 wherein the whiskers in the composition of the cutting tool insert are oriented in planes perpendicular to one axis.
- 17. A cutting tool insert consisting of compositionally: an alumina matrix, 10 to 50 volume percent single crystal titanium carbide whiskers distributed within said alumina matrix, and a residue of sintering aids up to 3 volume percent.
- 18. The cutting tool insert according to claim 1 wherein the alumina matrix is at least 99 weight percent Al.sub.2 O.sub.3 and the residue of sintering aids is up to 1 volume percent ZrO.sub.2.
- 19. The method according to claim 8 wherein the polycrystalline alumina matrix has an average grain size between 0.5 to 3 microns and the titanium carbide whiskers have a length ranging up to 150 microns.
- 20. The cutting tool insert according to claim 1 consisting of compositionally: the alumina matrix, 15 to 35 volume percent of the titanium carbide whiskers, and the residue of sintering aids is up to 1.5 volume percent.
- 21. The cutting tool insert according to claim 1 consisting of compositionally: the alumina matrix, 25 to 35 volume percent the titanium carbide whiskers, and the residue of sintering aids up to 1.5 volume percent.
- 22. The method according to claim 8 wherein the whiskers are randomly oriented.
- 23. The method according to claim 8 wherein the whiskers are oriented in planes perpendicular to one axis.
Parent Case Info
This is a continuation of U.S. application Ser. No. 07/505,951, filed Apr. 6, 1990, and issued as U.S. Pat. No. 5,397,370, on Mar. 14, 1995; which is a continuation of U.S. application Ser. No. 07/270,998, filed Nov. 14, 1988, and issued as U.S. Pat. No. 4,925,458, on May 15, 1990; which is a divisional of U.S. application Ser. No. 07/056,091, filed May 28, 1987, and issued as U.S. Pat. No. 4,852,999, on Aug. 1, 1989.
US Referenced Citations (12)
Foreign Referenced Citations (6)
Number |
Date |
Country |
0202504 |
Nov 1986 |
EPX |
0252046 |
Jan 1988 |
EPX |
0255709 |
Feb 1988 |
EPX |
0283454 |
Sep 1988 |
EPX |
3445766 |
Jun 1986 |
DEX |
954285 |
Apr 1964 |
GBX |
Non-Patent Literature Citations (4)
Entry |
"Encyclopedia of Materials Science and Engineering," vol. 7 T-2, MIT Press, (1986) pp. 5344-5346. |
Faber and Evans, "Crack Deflection Processes-I. Theory," Acta Metall., vol. 31, No. 4, pp. 565-576, (1983). |
A. Kato et al., "Growth Rate of Titanium Carbide Whiskers in Chemical Vapor Deposition," J. Cryst. Growth, 37, (1977), pp. 293-300. |
N. Tamari et al., "Catalytic Effects of Various Metals and Refractory Oxides on the Growth of TiC Whiskers by Chemical Vapor Depostion," J. Cryst. Growth, 46, (1979), pp. 221-237. |
Divisions (1)
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Number |
Date |
Country |
Parent |
56091 |
May 1987 |
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Continuations (2)
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Number |
Date |
Country |
Parent |
505951 |
Apr 1990 |
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Parent |
270998 |
Nov 1988 |
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