摘要
研究了自韧Si_3N_4的高温力学性能、氧化行为和抗热震性能。结果表明,晶界玻璃相对高温性能有重要影响,在室温～1350℃的范围内,自韧Si_3N_4的抗弯强度随温度的升高而降低,断裂韧性随温度的升高而增加;在1300～1350℃的温度范围内,自韧Si_3N_4的氧化符合抛物线规律,氧化过程主要由晶界处添加剂离子和杂质离子的扩散过程控制。由于热应力导致裂纹的产生和扩展,使得热震后材料的性能降低。
The high temperature mechanical properties,oxidation behavior,and thermal-shock of in-situ toughened Si3N4 are investigated. The results show that the effect of glassy phase on high tempermure properties is significant, the flexural strength of insitu toughened Si3N4 decreases and fracture toughness increases with temperature rising at RT-1350℃ ;oxidation of the materials in the temperature range of 1300-1350℃follows the typical parabolic law, oxidation procedure is mainly controlled by the diffusion of ions of additives and impurities segregated at the grain boundaries. After repeated rapid quenching, the mechanical properties of the materials reduce greatly, that is due to crack resulted in by thermal stress forming and propagating.
出处
《现代技术陶瓷》
CAS
1996年第3期19-22,共4页
Advanced Ceramics
关键词
氮化硅陶瓷
陶瓷
高温性
In-situ toughened Si3N4 Mechanical properties Oxidation Thermal shock
