The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 30, 1998
Filed:
Nov. 20, 1996
Ellen M Dubensky, Midland, MI (US);
Robert T Nilsson, Midland, MI (US);
The Dow Chemical Company, Midland, MI (US);
Abstract
A cemented tungsten carbide body having a transition metal binder phase selected from the group consisting of iron, nickel and cobalt is formed, wherein the WC grains have an average WC grain size of at most about 0.5 micrometer in diameter and a maximum WC grain size of at most about 0.8 micrometer in diameter. Also, about 50 percent by volume of the WC grains in the body are angular grains and the body (1) contains an amount of the transition metal ranging from about 3 percent to about 18 percent by weight of the body, (2) is essentially free of grain growth inhibitors and (3) is essentially pore free. Said cemented tungsten carbide body is formed by mechanically mixing a source of WC with a source of transition metal, shaping the mixture into a porous body and sintering the porous body at a sintering temperature, superatmospheric pressure and time at temperature and time at superatmospheric pressure sufficient to form the cemented tungsten carbide body, wherein the sintering occurs without the formation of a liquid in the body and at least a portion of the time at superatmospheric pressure is at the sintering temperature.