To contribute to a better understanding of the fracture mechanisms and stress distributions of aluminum cast alloy locally reinforced by SiC particle and Al_2O_3 whisker hybrid MMC a symmetrical four-point bending test was precisely analyzed experimentally and numerically. The four-point bending test was performed on straight beam specimens of rectangular cross section in the MTS machine, using special bending fixtures. The fracture mechanism and the fracture path ahs been investigated on the fracture surfaces. Crack initiation location and fracture surface morphologies have also been investigated. The stress distribution of SiC particle/Al_2O_3 whisker and homogeneous material joint have been calculated. Both the experimental results and the finite element simulation results show that the critical location for fracture is a region on MMC side near the interface.
