SiC颗粒增强铝基复合材料的热循环行为研究

Thermal Cycling Behavior of Aluminum Matrix Composites

摘要:

基于材料微观组织建立了视场胞元模型，并采用商用有限元软件ABAQUS对胞元模型进行温度循环的数值模拟，着重分析热循环中基体和增强颗粒的等效应力分布规律，及主应力σ11和σ22的分布规律。结果表明：在热循环的升温阶段，基体的主热应力整体表现为压应力，增强颗粒表现为拉应力；在降温阶段，基体表现为拉应力，增强颗粒表现为压应力；在模拟中，对3次循环中的主热应力σ22做了统计，发现不论是基体还是增强颗粒，从第2次循环开始，热应力就开始趋于稳定。通过改变单元胞中颗粒的体积分数进一步分析体积分数变化对颗粒增强金属基复合材料热循环的影响，结果发现体积分数减小之后，基体和增强颗粒应力分布变得均匀，并且各次循环中的热应力相差不大，比较稳定。最后对热循环中的应变滞后回线进行了分析，表明高体积分数下的复合材料具有高的热稳定性

Abstract:

A finite element modeling based on the actual microstructure is established to analyse the thermal cycling behavior of metal Al matrix composites (MMC). The distribution of Von Mises effective stress and principle stress is presented, and the results show that during the heating, the thermal stress is negative in matrix, but positive in particles; during the cooling, the thermal stress is positive in matrix, but negative in particles. Simultaneously, the principle stress s22 after three thermal cycles is calculated to be steady after the two cycles. The effect of volume fraction on the thermal cycles is analysed in the cell model, finding that the distribution of von Mises stress is more uniform than the previous model. Through comparison, it is shown that the composites with high volume particle fraction possess a higher dimensional stability