The effect of thermal cycling on the mechanical properties of sic whisker reinforced magnesium alloy-based composites

Abstract

The effect of thermal cyclings on mechanical properties at room and some elevated temperatures of SiC whisker-reinforced magnesium-matrix composites produced by squeeze casting and hot extrusion are clarified. Subsequent thermal cycling produces internal stress at the matrix/SiC whisker interfaces causing fatigue. The mechanical properties of composites are more influenced by the low thermal cycling of 298 K— 77 K than the high thermal cycling 673 K—298 K. The high thermal cycling of 673 K—298 K has only a slight affect on such mechanical properties as tensile strength and proof stress at temperatures lower than 473 K. However, at 473 K and 573 K, the thermal cyclings there almost no influence on the mechanical properties of SiC whisker reinforced AE42 alloy-matrix composites.