Gte Laboratories Incorporated

Valenite, Inc.

Sergej T Buljan

Helmut Lingertat

Steven F Wayne

A dense cermet article including about 44-93% of a granular first hard phase, about 4-44% of a granular second hard phase, and about 2-20% of a metal phase, all expressed in % by volume. The first hard phase consists essentially of alumina and from 0% to less than 5% of one or more oxides selected from magnesia, zirconia, yttria, hafnia, and silica. The second hard phase consists essentially of a hard refractory carbide, nitride, or boride, or mixture or solid solution thereof. Preferred materials for inclusion in the second hard phase are titanium carbide, hafnium carbide, tantalum carbide, tantalum nitride, tungsten carbide, titanium diboride, and boron carbide. The metal phase consists essentially of a combination of nickel and aluminum having a ratio of nickel to aluminum of from about 85:15 to about 88:12, and 0-5% of an additive selected from the group consisting of titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, cobalt, boron, and/or carbon. The preferred metal phase is substantially of the Ni.sub.3 Al ordered crystal structure.

Alumina ceramic-metal articles

A dense cermet article including about 80-95% by volume of a granular hard phase and about 5-20% by volume of a metal phase. The granular hard phase consists essentially of a ceramic material selected from the hard refractory carbides, nitrides, carbonitrides, oxycarbides, oxynitrides, carboxynitrides, and borides of titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, boron, and mixtures thereof. The metal phase consists essentially of a combination of nickel and aluminum having a weight ratio of nickel to aluminum of from about 90:10 to about 70:30 and 0-5% by weight of an additive selected from the group consisting of titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, cobalt, boron, or carbon, or combinations thereof. In the preferred metal phase, an amount of about 15-80% by volume of the metal phase component exhibits a Ni.sub.3 Al ordered crystal structure. The article may be produced by presintering the hard phase - metal phase component mixture in a vacuum or inert atmosphere at about 1475.degree.-1675.degree. C., then densifying by hot isostatic pressing at a temperature of about 1575.degree.-1675.degree. C., in an inert atmosphere, and at about 34-207 MPa pressure. Limiting the presintering temperature to 1475.degree.-1575.degree. C. and keeping the presintering temperature at least 50.degree. C. below the not pressing temperature produces an article of gradated hardness, harder at the surface than at the core.

Ceramic-metal articles and methods of manufacture

A dense cermet article including about 80-90% by volume of a granular hard phase and about 5-20% by volume of a metal phase. The hard phase is a carbide, nitride, carbonitride, oxycarbide, oxynitride, or carboxynitride of a cubic solid solution selected from W-Ti, W-Hf, W-Nb, W-Ta, Zr-Ti, Hf-Ti, Hf-Zr, V-Ti, Nb-Ti, Ta-Ti, or Mo-Ti. The metal phase consists essentially of a combination of nickel and aluminum having a ratio of nickel to aluminum of from about 90:10 to about 70:30 by weight, and 0-5% by weight of an additive selected from titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, cobalt, boron, and/or carbon. The preferred hard phase is a cubic solid solution of tungsten and titanium. In the preferred metal phase, an amount of about 15-80% by volume of the metal phase component exhibits a Ni.sub.3 Al ordered crystal structure. The article may be produced by presintering the hard phase - metal phase component mixture in a vacuum or inert atmosphere at about 1475.degree.-1675.degree. C., then densifying by hot isostatic pressing at a temperature of about 1575.degree.-1675.degree. C., in an inert atmosphere, and at about 34-207 MPa pressure. Limiting the presintering temperature to 1475.degree.-1575.degree. C. and keeping the presintering temperature at least 50.degree. C. below the hot pressing temperature produces an article of gradated hardness, harder at the surface than at the core.

Ceramic-metal articles

A method for manufacturing a dense cermet article including about 80-95% by volume of a granular hard phase and about 5-20% by volume of a metal binder phase. The hard phase is (a) the hard refractory carbides, nitrides, carbonitrides, oxycarbides, oxynitrides, carboxynitrides, borides, and mixtures thereof of the elements selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, and B, or (b) the hard refractory carbides, nitrides, carbonitrides, oxycarbides, oxynitrides, and carboxynitrides, and mixtures thereof of a cubic solid solution of Zr--Ti, Hf--Ti, Hf--Zr, V--Ti, Nb--Ti, Ta--Ti, Mo--Ti, W--Ti, W--Hf, W--Nb, or W--Ta. The binder phase is a combination of Ni and Al having a Ni:Al weight ratio of from about 85:15 to about 88:12, and 0-5% by weight of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Co, B, and/or C. The method involves presintering the hard phase/binder phase mixture in a vacuum or inert atmosphere at about 1475.degree.-1675.degree. C., then HIPing at about 1575.degree.-1675.degree. C., in an inert atmosphere, and at about 34-207 MPa pressure. Limiting the presintering temperature to 1475.degree.-1575.degree. C. and keeping the presintering temperature at least 50.degree. C. below the hot pressing temperature, produces an article of gradated hardness, harder at the surface than at the core.

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Acton, MA, United States of America

Sergej T Buljan