颗粒强化钛基复合材料的断裂特征

Fracture Characteristics of Particle-Reinforced Ti Matrix Composites

研究了TiCp强化钛基复合材料在室温静态拉伸条件下的断裂特征。结果表明,宏观断口表现为脆性断裂,高倍下为TiCp解理断裂和基体局部延性断裂相结合的混合断口。材料的失效受TiCp断开与基体塑性变形制约,由于TiCp的限制作用,基体的塑性变形很不充分。粒子中的空洞和工艺过程中的粒子损伤是主要的裂纹源。裂纹的传播则以沿晶或穿晶方式在基体中扩展,最终引起材料失效。

Fracture characteristics of TiCp reinforced Ti-matrix compositcs are studied at room temperature static tensile condition. The main macrofracture shows brittle fracture, which are mixed fracture with cleavage fracture of TiCp and partial ductile fracture of matrix under high amplification. The material failure is confined by TiCp breaking and plastic deformation of the matrix. Since the limitation of TiCp, the plastic deformation of the matrix is not sufficent. The main crack source is from the cavity within the particles and the damage of the particles during processing. These cracks propagate into matrix intergranularly or transgranularly, leading to the final material failure.