摘要
为提高AlON陶瓷材料的抗氧化性能 ,制备了AlON -SiAl7O2 N7复相材料。在 1 75 0℃、0 .5MPa的N2 气氛中 ,保温 2h烧成不同Al2 O3/AlN/Si3N4配比的原料得到不同AlON/SiAl7O2 N7比的复相材料。因为在烧结SiAl7O2 N7的过程中 ,蒸发-凝聚的同时伴随着SiO气体的挥发 ,因此很难得到致密的AlON -SiAl7O2 N7复相材料。研究了AlON -SiAl7O2 N7复相材料在 1 30 0℃、空气中的抗氧化性能 ,同时作为比较 ,研究了相同条件下单相的AlON材料的抗氧化性能。结果表明 ,AlON -SiAl7O2 N7复相材料显示了较之单相的AlON陶瓷材料更好的抗氧化性能 ,这是因为氧化过程中所形成的含玻璃相的表面氧化层抑制了氧的向内扩散所致。
AlON- SiAl 7O 2N 7 composites were prepared in order to improve the oxidation characteristics of AlON ceramics.Composites with different ratios of AlON/SiAl 7O 2N 7 were obtained by heating mixtures with different Al 2O 3/AlN/Si 3N 4 ratios at 1750 ℃ in 0.5 MPa N 2 for 2 h. Since sintering of SiAl 7O 2N 7 progresses by an evaporation condensation mechanism accompanied by evolution of SiO gas, densification of AlON- SiAl 7O 2N 7 composites is hard to achieve. The oxidation behavior of the obtained composites was investigated in air at 1300 ℃. Compared with a monolithic AlON material, the AlON- SiAl 7O 2N 7 composites showed higher oxidation resistance because the formed surface layer with glass phase inhibited inward diffusion of oxygen.
出处
《耐火材料》
CAS
北大核心
2003年第4期194-199,共6页
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