【摘要】 针对不同温度下(77,159,293和500 K)氮化硅陶瓷中产生的80条裂纹中的5764个裂纹偏转和428个桥接进行了统计分析;利用数值模拟方法定量研究了氮化硅陶瓷中晶界相断裂韧性对裂纹桥接行为的影响。结果表明:在不同温度下,氮化硅陶瓷中桥接形成几率随偏转角度变化趋势相似。当裂纹偏转角度为70°~90°时,桥接形成几率最高;温度变化对桥接形成影响较小。晶界断裂韧性对氮化硅陶瓷桥接有明显影响,过高或过低均不利于桥接的形成。更多还原

【Abstract】 Crack bridging were investigated by elaborative observation of 5764 crack deflections and 428 bridges, generated at 77 K, 159 K, 293 K and 500 K, in silicon nitride（Si₃N₄） ceramics. The effect of grain boundary toughness on crack bridging behavior was investigated quantitatively using numerical simulation methods. The results show that the formation probability of bridging in silicon nitride ceramics is similar at different temperatures. When the crack deflection angle is in the range of 70°⁹0°, the formation probability of bridging is highest. Grain boundary toughness of silicon nitride ceramic bridge has obvious influence on the formation of bridging, which should not be too high or too low.更多还原