Numerical and experimental research on micro-damage of SiCp/A356 composites

Macroscopically mechanical behaviors were closely related with the micro-damage mechanism of SiC particle reinforced aluminum matrix composites. With the temperature increasing, the mechanical properties of the composites decreased significantly, the reason of which was the micro-damage mechanism of the composites was different at different temperature. The unit cell model for the SiCp/A356 composites was established which consists of a spherical SiC particle and aluminum matrix. On the basis of the model, the simulation study on the micro-damage mechanism of the composites was carried out. The micro-damage mechanism of the composites from the finite element simulations was consistent with the results from the experimental investigations. It can be concluded that the crack initiation mechanism of the composites at room temperature was mainly tear of the matrix and fracture of SiC particles mainly; while the mechanism of the composites at high temperature was SiC particle debonding from the matrix and tear of the matrix.