原位自生TiB2/A356复合材料拉伸行为的细观分析

摘要

采用原位自生法制备了TiB2/A356复合材料,并对该材料的拉伸性能进行了研究.结果表明,随着颗粒体积分数的增加,复合材料的弹性模量、屈服强度和抗拉强度增大,而延性稍有下降.断口观察表明,其主要断裂机制为颗粒与基体界面脱粘和颗粒团聚内部疏松引起的脆性开裂.针对此种复合材料提出一种弹性模量简化计算模型,同时对其屈服强度也进行了细观分析.%The in-situ TiB2/A356 composites were fabricated by the exothermic reaction process. And their tensile properties were investigated. Results showed that the elastic modulus, yield strength and ultimate tensile strength increase with increasing TiB2 content. But the elongation of the composites is a little bit reduced compared with the matrix. The fracture surface show that the main failure mechanisms of the composites are matrix/particle in terface failure and matrix brittle fracture due to TiB2 agglomeration. Furthermore, a simplified elastic module model of TiB2/A356 composites is proposed and the yield strength of the composites is micromechanical analyzed.