【摘要】 分析研究了纳米复合陶瓷材料的断裂模式和应力场情况，提出纳米复合陶瓷韧性增加是主晶界强化和晶粒分化共同作用的结果。晶界纳米相能和基质形成高强度主晶界，从而对沿晶裂纹起强“钉扎”作用；晶内纳米相的增初作用在于形成有利于穿晶断裂的应力场，再加上微裂纹和次界面，使晶界得以强化，而基质晶粒趋向脆化。若纳米相过多，基体得到细化，但晶内纳米颗粒的应力作用更加突出，不利于断裂韧性的提高。更多还原

【Abstract】 The fracture modes and residual stress of ceramic nano-compeites were studied. It is suggested that toughening of the nano-composites is a result which is combined by strengthening of main boundaries with brittle effect of matrix grains. The main boundaries possess much strong bonding because of intergranular nanoparticles, so it is mere effective to pin cracks. Toughening action of intragranular nanoparticles are formation of residual stress fields which is advantageous to cracks’ trans granular propagation, and formation of microcracks and sub-grain boundaries. So the grain boundaries are strengthened but the matrix grains tend to brittleness. If the quantity of nanoparticles in the composites is excessive, the toughness of the materials would be decreased because stress effect in grains would be stronger despite finer grains.更多还原