【摘要】 用扫描电镜、透射电镜及努氏压痕法研究了添加SiC晶须、纳米颗粒及晶须和纳米颗粒的三种Si3N4基复相陶瓷在外力作用下的断裂行为。这三种材料断裂的主要方式是沿晶断裂 ,偶尔可见穿晶断裂。在裂纹发展的路径上当裂纹尖端遇到了晶须、集聚的纳米颗粒及类晶须时 ,会产生扭转、偏转、断裂、拔出和终止 ,从而使裂纹能量消耗 ,抑制和阻碍了裂纹的扩展和传播 ,起到了增韧补强的作用。更多还原

【Abstract】 Fracture behavior of SiC(W)/Si 3N 4,SiC(n)/Si 3N 4,SiC(n,w)/Si 3N 4 composite ceramics under loading was studied using SEM,TEM and Knoop indentation method.The result indicates that the fracture character of three composites is mainly intergranular fracture,once in a while shows transgranular fracture on crack path,when the crack encountered whiskers,nano grains and quasiwhiskers,turning,deflection,twist,pulling out and stop of the crack occurred,resulting in depletion of crack propagating energy,so that the development and propagation of the crack were restrained and hindered and hence the strength and the fracture toughness of the nano composites were increased.更多还原