Rutgers, The State University of New Jersey

Nanodyne Incorporated

Rajendra K Sadangi

Larry E McCandlish

Bernard H Kear

Oleg Voronov

A method for fabricating a triphasic composite such as a WC/Co/diamond composite with a high volume fraction of diamond in a WC/Co matrix. The method involves sintering of a WC/Co powder compact to develop a porous preform, which displays some rigidity and strength, infiltrating the porous preform with a controlled distribution of carbon, and high pressure/high temperature treatment of the carbon-containing WC/Co preform to transform the carbon to diamond. The distribution of diamond in the composite can be functionally graded to provide a WC/Co core and a diamond-enriched surface, wherein all three phases form an interconnected structure in three dimensions. Such a tricontinuous structure combines high strength and toughness with superior wear resistance, making it attractive for applications in machine tools and drill bits.

Triphasic composite and method for making same

A low melting point alloy is used to sinter metal carbide particles. The alloy is a eutectic-like alloy formed from a binding metal such as iron, cobalt or nickel, in combination with vanadium and chromium. The alloy is preferably formed by forming two separate alloys and blending these together. The first alloy is formed by spray drying together a solution of a binding metal salt such as a cobalt salt with a solution of a chromium salt. The formed particles are then carburized to form a cobalt-chromium-carbon alloy. A separate vanadium alloy is formed in the same manner. The two are combined to establish the amount of chromium and vanadium desired, and this, in turn, is used to sinter metal carbide parts. This permits sintering of the metal carbide parts at temperatures less than 1250.degree. C. and in turn significantly inhibits grain grown without a significant decrease in toughness. It is particularly adapted to form carbide products wherein the carbide grain size is as low as 120 nanometers.

Growing community of inventors

Highland Park, NJ, United States of America

Rajendra K Sadangi