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Y-α-β Sialon复相陶瓷的显微结构和蠕变行为

林明通; 蒋丹宇; 汪霖; 阮美玲; 施剑林   

  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
  • 收稿日期:2000-12-12 修回日期:2001-01-10 出版日期:2001-11-20 网络出版日期:2001-11-20

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

LIN Ming-Tong; JIANG Dan-Yu; WANG Lin; RUAN Mei-Ling; SHI Jian-Lin   

  1. State Key Lab of High Performance Ceramics and Superfine Microstructure; Shanghai Institute of Ce- ramics; Chinese Academy of Sciences; Shanghai 200050; China
  • Received:2000-12-12 Revised:2001-01-10 Published:2001-11-20 Online:2001-11-20

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.

关键词: 复相sialon, 蠕变, 显微结构, 氧化, 相变

Abstract: 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 1250~1350℃ and stresses of 110~290MPa in air. The stress exponents at 1250, 1300 and 1350℃ were found to be 1.31, 1.49 and
1.62, respectively, and creep activation energy was 677kJ·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.

Key words: sialon composite, creep, microstructure, oxidation, phase transformation

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