The effect of Sr addition on microstructure and mechanical properties of LM6 alloy is investigated. The Sr addition changes the eutectic Si flakelike morphology of base alloy to fibrous form, promotes the formation of equiaxial α-Al, and reduces the size of the flake-like β-phase. These modifications improve yield strength, ultimate tensile strength, and percentage elongation. Furthermore, the fractography reveals the ductile behaviour of the LM6-Sr alloy, whereas the base alloy failed in a brittle manner.
