| 摘要 |
A refractory dispersion comprises Mo, W, Cr or Re, or an alloy of two or more thereof or an alloy of at least one thereof with a minor amount (by weight of the alloy) of a conventional alloying element (viz. Fe, Ni, Co, Ti and Zr) in which is dispersed, as an essential nitride, at least one of the nitrides of Al, Ti, Zr, Ta, Hf, Nb or V to constitute at least 5% by volume of the non-metal component. The nitride may be included at the rate of 1-99 parts by volume per part by volume of metal. In order to getter minor amounts of impurities such as C and O, there may be added minor amounts of Al, Th, La, Ti, Zr or V, usually in an amount slightly in excess of that required to combine stoichimetrically with the impurities. The essential nitride may be partially replaced by one or more of the following:-nitrides of U, B, Be, Mg, Ce or Th, carbides of Ti, Zr, Ta, Si or Nb, oxides of Mg, Zr, Al, Ti or Th or Ti or Zr mono-borides in an amount up to 95 volume % of the non-metals in the dispersion but preferably no more than 50% thereof. The dispersions are made by standard powder metallurgical techniques.
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