DENSE, SHAPED ARTICLES CONSTRUCTED OF A REFRACTORY MATERIAL AND METHODS OF PREPARING SUCH ARTICLES

摘要

A dense, shaped article comprising at least about 95% by weight 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, wherein the article has a melting point of at least about 2900 °C, a density of at least about 90%, a total porosity of no more than about 10%, and a total open porosity of no more than about 1.0%.