FRACTOGRAPHIC ASPECTS OF AL-ALLOY / SiC_P METAL MATRIX COMPOSITE SUBJECTED TO STATIC, DYNAMIC AND CYCLIC MECHANICAL LOADING

摘要

AA356 alloy/SiC_p compocast billets were produced via Vortex-Stir Compocasting technique and machined testpieces were subjected to static flexural, Charpy impact and fatigue testing with subsequent fractographical evaluation of broken specimen halves. Experimental results showed that T6 tempering increased both flexural stiffness and ultimate strength by 20% as compared to the properties of non-aged composite. Increasing temperature was found to have a beneficial effect on the impact toughness of T6 heat-treated composite. However, flexural strength of AA356-T6 alloy was impaired by 20% due to SiC particulate blending, and fatigue life was 10 to 25% shorter due to thermal aging of the composite. Documented evidence via microfractographic analysis is provided to shed some light on controlling mechanisms of fracture.