室温下单晶硅压痕微裂纹的形成与扩展

Indention microcrack formation and propagation in single crystalline silicon at room temperature

用透射电镜定位观察研究了在室温下高纯单晶硅显微压痕表面radial脆性微裂纹的纳观形变 ,阐述了塑性变形对微裂纹形核、扩展及开裂的影响。发现 :室温下单晶硅的压痕前沿经历了极复杂的非线性演化 :前沿区的位错发射与运动 (Kcleave>Kemit时 )、解理微纹形核与扩展 (σ塞 >σth 时 )。

Nano scope deformation of radial brittle micro cracks initiated by indentation was investigated in pure high single crystalline silicon by TEM positioning observation at room temperature, and the effect of plastic deformation on micro crack nucleation, extension and cleavage was interpreted. It was found that the sophisticated no liner change performed ahead of crack in single crystalline silicon at room temperature, that is, dislocation emission and motion ( K cleave > K emit ),cleavage micro crack nucleation and propagation( σ > σ th ).The cleavage induced by plasticity, discontinuous nucleation and propagation of the cleavage embryo were observed ahead of indention.