EFFECT OF POST HEAT TREATMENT AFTER SQUEEZE CASTING ON THE MICRO-STRAIN INDUCED BY THERMAL STRESS IN THE SHORT FIBER REINFORCED PISTON ALLOY

摘要

Metal matrix composites offer increased specific strength and stiffness and low thermal expansion coefficient over monolithic materials. However, due to the mismatch in thermal expansion coefficients between matrix and reinforcement, any fluctuation in environmental temperature could introduce large thermal stress that is possible to cause the local plastic deformation in the matrix near the reinforcement, leading to instability in component dimension and possible degradation in mechanical properties during service. This paper investigates the effect of post heat treatment after squeezing casting on the micro-strain induced by thermal cycling in the short fiber reinforced piston alloy.