Fatigue surface analysis of AL A356 alloy reinforced hematite metal matrix composites

This study intends to investigate how copper chill affects the fatigue behaviour of composites made of aluminium alloy A356 and hematite. It was cast by altering the weight fraction particles of hematite (0 to 12%wt in increments of 3%wt) by sand casting method with and without copper chills at its end to get isotropic and homogenous significant characteristics under liquid metallurgical way. The test specimens were prepared in accordance with ASTM specifications. Ducom-type fatigue testing equipment (rotating bending-low cycle fatigue) is used in experiments to examine fatigue behaviour. The micrographic images were taken with a scanning electron microscope (SEM) and interpreted uniform reinforcement of hematite particles, and X-ray diffraction (XRD) patterns were used to reveal microscopic details. The existence of the hematite particles and their phases was revealed by the X-ray diffraction analysis. The results show that the composites cast with copper chills have significantly greater fatigue strength than the casting obtained without copper chills. It was also observed that at 9%wt, copper chilled composite shows improve in fatigue strength about 10.2% as compared without chilled composites.