Y-α-β Sialon复相陶瓷的显微结构和蠕变行为  

Microstructure and Creep Behavior of a Y-α-β Sialon Composite

作　　者：林明通[1] 蒋丹宇[1] 汪霖[1] 阮美玲[1] 施剑林[1] 

机构地区：[1]中国科学院上海硅酸盐研究所高性能陶瓷和超微结构国家重点实验室,上海200050

出　　处：《无机材料学报》2001年第6期1113-1120,共8页Journal of Inorganic Materials

基　　金：国家自然科学基金项目(59772008)

摘　　要：研究了一种以ＹＡＧ为晶界相和理论初始α／β比率为６５／３５的Ｙ－α－β复相ｓｉａｌｏｎ在温度１２５０～１３５０℃和应力１１０～２９０ＭＰａ的四点弯曲蠕变行为，得出在１２５０、１３００、１３５０℃下的应力指数分别为１．３１、１．４９、１．６２，蠕变激活能为６７７ｋＪ.ｍｏｌ-1，显微结构观察表明几乎所有的空洞都位于多晶界，从而推断伴随着多晶界空洞形成的扩散－滑移耦联机制是蠕变的速率控制机制．Ｍｏｎｋｍａｎ－Ｇｒａｎｔ关系式得出的蠕变速率指数p值为１.６，蠕变断裂是由多三晶界空洞的成核、生长、聚结和连接引起的．Four-point bending creep behaviour of a Y-α-β sialon composite with YAG as the intergranular phase and with the theoretical α/β ratio of 65/35 was studied at temperature 1250-1350°C and stresses of 110-290 MPa in air. The stress exponents at 1250, 1300 and 1350°C were found to be 1.31, 1.49 and 1.62, respectively, and creep activation energy was 677 kJ&middotmol-1. Cavities were found mainly on multi grain junctions. Grain boundary diffusion coupled with sliding was identified to be the dominant creep deformation mechanism. The creep rate exponent, p, in Monkman-Grant relation was 1.6, and the nucleation/growth, coalescence and linkage of multi-grain-junction cavities were responsible for the creep rupture.

关 键 词：蠕变 显微结构 氧化 相变 蠕变断裂 Y-α-βSialon复相陶瓷 蠕变变形 

分 类 号：TQ174.758[化学工程—陶瓷工业] TQ174.1[化学工程—硅酸盐工业]