摘要
研究了Ｌａ－Ｙ—Ｓｉ３Ｎ４陶瓷的高温力学性能、氧化行为和抗热震性．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，随温度升高，Ｓｉ３Ｎ４的抗弯强度降低，断裂韧性增加；在１３００～１３５０℃的温度范围内，Ｓｉ３Ｎ４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。
The high temperature mechanical properties, oxidation behavior, and thermal shock of La-Y-Si3N4 are investigated. The results show that the effevt of glassy phase on high temperature properties is significant, the flexural strength of 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 because of the forming and propagating of cracks by thermal stress.
出处
《材料研究学报》
EI
CAS
CSCD
1996年第1期81-84,共4页
Chinese Journal of Materials Research
关键词
力学性能
氧化
热震
氮化硅陶瓷
镧
钇
Si_3N_4 mechanical properties oxidation thermal shock
