Finite element analysis of the influence of interphase on the thermal residual stress level and distribution of SiCp/6061Al composites

The influence of interphase on the level and distribution of thermal residual stress (TRS) in SiCp/6061Al composites was studied by using a three-dimensional (3D) interface-phase model. The thermal expansion coefficient and elastic modulus of interphase components were the main factors affecting the TRS level in SiCp/6061Al composites. The formed SiC-MgO-6061Al interphase has highly concentrated TRS, and the formed SiC-Si-6061Al interphase had the lowest TRS level. With the increase of interphase thickness, for most interphase components, the TRS in SiCp/6061Al composites showed a trend of first decreased and then increased. When the interphase thickness was 1.2 mu m, it had the lowest TRS level. When the SiC particle aspect ratio was large, the TRS was mainly concentrated in the sharp corner region jointly formed by the reinforcement and interphase. As the SiC particle aspect ratio decreased, the sharp corners of interphase become passivated, the level of TRS in the reinforcement and interphase of SiCp/6061Al composites also gradually decreased. The research results were based on the 3D interface-phase model and generally consistent with the actual experimental analysis.