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:
Mar. 18, 1997
Filed:
Nov. 13, 1995
Robert T Nilsson, Coleman, MI (US);
Richard T Fox, Midland, MI (US);
Stephen D Dunmead, Midland, MI (US);
The Dow Chemical Company, Midland, MI (US);
Abstract
A method of forming a low level carbon high-density tungsten carbide-containing material includes sintering a preform which contains tungsten carbide powder and has a composition such that the resulting sintered material has at most 6.05 weight percent tungsten-bound carbon based on the total weight of tungsten and tungsten-bound carbon. This low level of carbon may be achieved by, prior to the sintering step, oxidizing the tungsten carbide powder sufficiently to achieve the desired substoichiometric carbon level in the sintered product or by adding a carbon-lowering material selected from the group consisting of tungsten, ditungsten carbide, and tungsten oxide. Optionally, other materials can be present in the preform such as carbon-getter metals and compounds thereof. The carbon-getter metals are those metals of which the carbides thereof are more thermodynamically stable than monotungsten carbide.