Ca－α－Sialon／SiC纳米相复合材料

Ca-α-Sialon/SiC Nano-phase Composite

本文通过反应热压压制备了Ｃａ－α－Ｓｉａｌｏｎ／ＳｉＣ纳米相复合材料．显微结构研究表明，α－Ｓｉａｌｏｎ（α’）晶粒细小，成等轴状；ＳｉＣ颗粒直径在５０～１５０ｎｍｎ左右，颗粒较大的分布于α’三晶粒的交叉处，颗粒较小的可以被包裹在α－Ｓｉａｌｏｎ的晶粒内部．纳米相ＳｉＣ的加入对裂纹扩展具有较大的阻碍作用，从而强化晶界，使材料的强度和硬度都有明显提高．

Ca-α-Sialon/SiC nanthphase composites were prepared by hot-pressing. The α-Sialon(α') grains were very fine and equiaxed in microstructure, and nano-scale SiC particles (50￣150nm) dispersed mainly at the triple points of α' grains and also some within the matrix grains. The intergranular fracture was dominant in the composites. The fact that the crack propagated not along the grain boundaries between Sialon and SiC, implies the SiC particles strengthened the grain boundary and inhibited the crack propagation.