原位TiB2颗粒增强铝基复合材料及其力学性能

对原位反应合成TiB2／A356铝基复合材料微观组织和力学拉伸性能进行了研究。结果表明，原位反应生成的颗粒增强相在复合材料基体中分布均匀，基体与颗粒间的界面洁净。复合材料强度随着颗粒含量的增加显著提高，与基体合金相比，TiB2质量分数为8％的TiB2／A356复合材料强度和弹性模量的提高幅度约为28％，TiB2质量分数为16％的TiB2／A356复合材料强度和弹性模量的提高幅度约为35％。复合材料的断裂主要是由于基体与颗粒界面脱粘，在拉伸应力作用下由此萌生微裂纹并扩展，导致界面处的基体撕裂，从而降低复合材料塑性。

Mechanical Properties and Fracture Morphology of In-situ TiB2 Particle Reinforced Aluminum Matrix Composites

Microstructure and mechanical properties of the in-situ synthesized A356/TiB_2 composites have been investigated. It was revealed that in-situ reinforced particle can be uniformly distributed into the matrix without interfacial reaction, and the strength of the composites is increased with increasing in reinforced particle content. Compared with that of the matrix alloy, the tensile strength and elastic modulus of the composites with 6% and 8% volume fraction are improved by about 28% and 35%, respectively. The fragile fracture occurs in reinforcement clusters and debonding of the interface between particle and matrix are responsible for the initiating and propagating micro-crack, resulting in fracture of matrix in the vicinity of interfaces and decrease of ductility of the composites.