Ceramic compositions for wear resistant applications
AssigneeElectrofuel Manufacturing Co.
InventorsRakesh Bhola, Sankar Dasgupta, James K. Jacobs
Life of this patent
Estimating the term…
Abstract
A composition for hard, sintered, tough and wear resistant ceramic articles is described. The composition is comprised of alumina, titanium carbonitride and filaments of titanium diboride or titanium nitride. The ceramic articles made of this composition are isostatically hot pressed or sintered at high temperature in inert gas. The density of the ceramic articles is usually in excess of 99% theoretical density and the hardness is greater than 20 GPa. The process was applied to manufacture ceramic cutting inserts of the above composition.
Claims7
A composition for a hard, sintered ceramic article, essentially consisting of:
- 50-80% by volume alumina,
- 5-40% by volume titanium carbonitride, the nitride and carbide content in said carbonitride being defined such that the fraction C/C+N has a value between 0.1 and 1,
- 1-30% by volume polycrystalline filaments selected from the group consisting of titanium diboride, titanium nitride and alloys thereof, said filaments having diameters in excess of 4 .mu.m and lengths greater than 150 .mu.m, and a grain growth modifier in less than 0.1 wt. %, selected from the group consisting of magnesia, nickel oxide and cobalt oxide;
- said hard ceramic article having density in excess of 99% of the theoretical density defined by said composition, subsequent to sintering, and said sintered ceramic article having hardness greater than 20 GPa.
A sintered ceramic cutting insert having composition essentially consisting of:
- 50-80% by volume alumina,
- 5-40% by volume titanium carbonitride, the nitride and carbide content in the carbonitride being defined such that the fraction C/C+N has a value between 0.1 and 1,
- 1-30% by volume polycrystalline filaments selected from the group consisting of titanium diboride, titanium nitride and alloys thereof, said polycrystalline filaments having diameters in excess of 4 .mu.m and lengths greater than 150 .mu.m, and
- a grain growth modifier in less than 0.1 wt. %, selected from the group consisting of magnesia, nickel oxide and cobalt oxide;
- said ceramic cutting insert having density in excess of 99% of the theoretical density defined by said composition, subsequent to sintering, and said sintered ceramic cutting insert having hardness values greater than 20 GPa.
Dependencies are inferred from the claim text.