Effect of Strontium and Silicon Carbide on Mechanical Properties of Aluminum Alloy (Lm6)

Abstract

A study of the addition different weight percentages of strontium and its influence on the mechanical properties and microstructure of Aluminum LM6 modified by (0.01, 0.02, 0.5) wt% strontium (Sr) was conducted, with the purpose of evaluating the properties of particulate silicon carbide (Sic), as reinforcement as well as the effect of a high Sr content. The obtained results indicated that addition of Al-10Sr improves the UTS and hardness of Aluminum and composite. Moreover, it is observed that adding Sr to the Al-SiC composite increased the amount of α-Al. The mechanical properties of the composite can be related to the volume fraction of dendritic α-Al, which can improve the mechanical properties of Aluminum or Al-Sic composite. it is concluded that the tensile for the composite did not increase dramatically because of weak interface between particles and matrix decrease the UTS, on the other hand strong interface between particles or fibers in the matrix show high stiffness and strength but typically a low resistance to fracture. Before tensile testing, heat treatment should apply to the samples to increase the ductility and ultimately UTS. In this research, a scanning electron microscope equipped with EDS is used to define the modification effects on microstructure and as result, on mechanical properties. Keywords- AL-SiC composite; Stir casting; Sand casting; Modifier; LM6.