Elevated Temperature Mechanical Properties of Squeeze Cast Metal Matrix Composites for Diesel Pistons

The tensile and fatigue strengths of squeeze cast F332 aluminum alloy and its composites reinforced with 15 volume percent of discontinuous Fiberfrax^® fiber after T5 heat treatment were determined at 400°C. Rotating beam fatigue testing was performed to determine the endurance strength of these composites for 50% probability of failure at 10 million cycles.

Substantial improvements in tensile and fatigue strengths were observed for the reinforced material compared to the matrix alloy. Long term 400°C thermal aging study indicates that there is no significant difference in fatigue strength between 100 hour and 1,000 hour aged samples.