| 摘要 |
A refractory dispersion comprises one or more of Mo, W, Cr, Re, Fe, Co or Ni in which is dispersed silicon nitride and a pressing adjuvant selected from Mg3N2Si3N Al2O3, MgO SiO2 B2O3 and the spinels of MgO, FeO, CoO or NiO associated with Al2O3, Fe2O3 or Cr2O3 (the divalent and trivalent oxides being of different metals). The dispersions preferably contain 1 - 98 parts of silicon nitride per part of metal and 0.002 - 10 parts of pressing adjuvant per part of metal (all parts being by volume). Up to 50% by volume of the silicon nitride may be replaced by one or more of the nitrides of Hf, Ti, Zr, Al, Ta, ThU and Ce the carbides of Mo, W, Hf, Cr, Ta, Nb, Ti and Zr and the silicides and disilicides of Cr, W and Mo. The compositions are prepared by powder metallurgical techniques.
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