中文摘要：

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-c-β复相sialon在温度1250～1350°C和应力110～290MPa的四点弯曲蠕变行为,得出在1250、1300、1350°C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.

英文摘要：

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·mol-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.