| 摘要 |
A fully dense ceramic-metal body including about 40-68 v/o alpha -alumina; about 10-30 v/o of a granular, hard refractory carbide, nitride, or boride; about 20-40 v/o silicon carbide platelets or elongated grains; and about 2-10 v/o of a dispersed metal phase combining Ni and Al mostly segregated at triple points of the microstructure. The preferred metal phase contains a substantial amount of the Ni3Al ordered crystal structure. In the preferred body, the reinforcing SiC phase is partially incorporated into the alumina grain, and bridges the grain boundaries. The body including a segregated metal phase is produced by densifying a mixture of the hard phase components and the metal component, with the metal component being present in the mixture as Ni powder and Al powder. The body may be used as a cutting tool for machining nickel superalloys or cast iron at speeds up to about 1000 sfm, feed rates up to about 0.012 in/rev, and depth of cut up to about 0.10 inches.
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