Thermal fatigue behaviour of SiCp/Al composite synthesized by metal infiltration

The thermal fatigue behaviour of SiCp/Al composite synthesized by infiltration of molten aluminium alloy into a preform of 65 vol.% SiCp was studied for the crack propagation and fracture surface characteristics. Specimens containing a V-shaped notch were found to commence crack initiation at the notch tip after about 15 cycles of thermal shock, produced by quenching in water from 300 deg C. Through the study of the fracture surface, it was found that the thermal fatigue crack initiation and propagation of this kind of composite was facilitated by mainly fracturing the large reinforcing particles in the composite by thermal shock. It has been shown that by reducing the size of the reinforcing particles would increase the resistance of this kind of composite against thermal fatigue.