热等静压法制备SiC_p/Al复合材料的组织及性能研究

Microstructure and properties of SiC_p/Al composites prepared by hot isostatic pressing

采用热等静压法制备SiC颗粒增强铝基复合材料,研究其显微组织和力学性能,分析复合材料的断口形貌及断裂机制,测定了其热膨胀系数。结果表明：热等静压后,复合材料中的SiC颗粒会出现颗粒团聚,形成硬质的SiC骨架。对于20%SiCp/6061Al（体积分数）复合材料,其抗拉强度能达到304 MPa,而20%SiCp/2024Al（体积分数）的抗拉强度为276 MPa,两种复合材料的抗拉强度都达到或超过其他制备方法的水平。复合材料的断裂方式为基体的韧性断裂、SiC颗粒的解理断裂、SiC颗粒与基体的界面脱粘3种方式并存的混合断裂形式。对比复合材料热膨胀系数的实际测量值和Turner、Kerner模型理论值,Turner模型理论值更接近实测值。

SiC particles reinforced aluminum matrix composites were prepared by hot isostatic pressing（HIP）.Microstructures and mechanical properties of the composites were studied. The fracture morphology and mechanism were analyzed and the thermal expansion coefficient of composites was also measured. The results show that the SiC particles in the composites agglomerate and form a hard SiC skeleton after hot isostatic pressing. The tensile strength of 20% SiCp/6061 Al（volume percent）composites reaches 304 MPa,while the tensile strength of 20%SiCp/2024 Al（volume percent）composites reaches 276 MPa. The tensile strength of both composites reaches or exceeds the level of other preparation methods. The fracture mechanism of composites is the ductile fracture of the matrix,the cleavage fracture of SiC particles and the interface stripping between SiC and matrix. The thermal expansion coefficients of composites are compared with Turner and Kerner theory values. It shows that the numerical value of Turner model is closer to the experimental value.