| 摘要 |
Refractory ceramics and composite materials consisting of nitrides, carbides, mixed carbides and oxides, oxycarbides, mixed nitrides and oxides, and oxynitrides of Group IVB metals Hf, Zr, and Ti, Group IIA metals Be, Mg, Ca, Sr, and Ba, and Group IIIB metals Sc, Y, and lanthanides La through Lu are used to form refractory articles, or as coatings for refractory articles. These materials and articles have high resistance to molten metals, molten salts, erosion, and high temperature corrosive environments, and can be engineered to have desirable thermal and electrical properties. The refractory materials encompass nitrides, carbides, reacted ternary and quaternary oxides, mixed carbides and oxides, oxycarbides, mixed nitrides and oxides, and oxynitrides and have the general chemical formula Mx1M'x2M''x3NyCwOz where M is Hf, Zr, or Ti, M' is Be, Mg, Ca, Sr, or Ba, M'' is Sc, Y, and lanthanides La through Lu, N is nitrogen, C is carbon, O is oxygen. In particular, nitrides having at least 54 atomic percent metal, ternary oxides having no more than 66.6 atomic percent oxygen, and oxynitrides having at least 33.4 atomic percent metal are preferred. Substoichiometric GroupIVB-GroupIIA and Group IVB-GroupIIIB ternary oxides are also preferred.
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