Patent ID: 7632454

Claim:
A method of forming a dense, shaped article formed of a refractory material, comprising; providing a refractory material powder having a melting point of at least about 2900° C., the refractory material powder consisting of a refractory material selected from the group consisting of carbides of tantalum, niobium or hafnium, nitrides of tantalum, niobium or hafnium, and alloys or powder mixtures thereof; placing the refractory material powder in a mold configured to form the powder into a desired shape; treating the mold containing the powder at a temperature and pressure sufficient to form a self-supporting and shape-sustaining molded powder that conforms to the shape of the mold, wherein said treating step comprises applying an isostatic or uni-axial pressure; machining the shape-sustaining molded powder to further shape the molded powder; and sintering the shape-sustaining molded powder in an inert atmosphere at a pressure ranging from vacuum to about 10 atm and at a temperature and for a time sufficient to produce a dense shaped article having a density greater than about 90%, a total porosity of no more than about 10%, and a total open porosity of no more than about 1%.