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用Si_3N_4,SiO_2和Al_2O_?作原料,以Y_2O_?为添加剂,研究了O’-β’所在的四个相容性区中组成,于1400—1800℃之间,O’和β’的形成动力学。O’于1400℃开始生成,1600℃达到最大形成量。高于1600℃,O’减少乃至消失。研究发现,O’的这种不稳定性,并非自身热分解的结果。Al含量的增加,液相出现和β’的形成,才是导致O’-Sialon溶解而消失的原因。 此外,认为Si_3N_4-O’(x=0.3)-Y_2Si_2O_7-YAG相容性区,是在制备具有合理的O’-β’平衡相组成的复相陶瓷时,可供实际选用的组成区。
Using Si_3N_4, SiO_2 and Al_2O_2O as raw materials and Y_2O_2O as additive, the composition of the four compatible regions containing O’-β ’was studied and the formation of O’ and β ’at 1400-1800 ℃ learn. O ’begins to form at 1400 ° C and reaches the maximum formation at 1600 ° C. Above 1600 ° C, O decreases or even disappears. The study found that this instability of O ’is not the result of self-thermal decomposition. The increase of Al content, the appearance of liquid phase and the formation of β ’are the reasons why O’-Sialon dissolves and disappears. In addition, it is considered that the Si_3N_4-O ’(x = 0.3) -Y_2Si_2O_7-YAG compatibility region is a practical compositional region for the preparation of a multi-phase ceramic having a reasonable O’-β’ equilibrium phase composition.