SiC－AlN－Y_2O_3复相陶瓷的氧化行为

Oxidation Behavior of SiC-AlN-Y_2O_3 Multiphase Ceramic

经研究致密的ＳｉＣ－ＡｌＮ－Ｙ２Ｏ３复相陶瓷的氧化行为后发现，陶瓷材料的表面在空气中氧化的反应物随着温度的高低而变化．８００℃、２０ｈ氧化试验后，试样表面无任何变化，１１００℃氧化．２０ｈ，表面形成了极少量的ＳｉＯ２，但两者均无增重．１２５０℃与１３２０℃氧化３０ｈ后，试样的重量和表面发生较明显的变化，形成了ＳｉＯ２与α－Ａｌ２Ｏ３，１３７０℃氧化试验３０ｈ后，陶瓷表面的氧化产物ＳｉＯ２与α－Ａｌ２Ｏ３转化成莫来石（３Ａｌ２Ｏ３·２ＳｉＯ２）结构．试样表面的氧化层均匀而且致密．

The oxidation behavior of dense SiC-AlN-Y2O3 multiphase ceramic was studied. The oxidation products of the sample surface were different when the oxidizing temperature increased. After heattreatment for 20h in air, the surface products oxidized at 800℃ didn't change, and a little SiO2 can be formed at 1100℃, but all the samples didn't gain any weight. Then the sample surfaces heat-tested for 30h at 1250 or 1320℃ became obviously oxidation products of SiO2 and α-Al2O3. The products formed mullite (3Al2O3·2SiO2) structure on the oxidized multiphase ceramic surfaCe when oxidized for 30h at 1370℃ in air. At the same time, there was a layer of dense oxidation film existing on the surface.