Correlation between tensile strength and microstructural properties of LM6 semi-solid cast alloy ball-milled with Si-rich/Al powder

ABSTRACT This experimental study deals with the effect of modifying an Si-rich LM6 cast alloy by ball milling with Si/Al powder particulates in which alloying was conducted via semi-solid liquid processing. The cast alloys were analyzed via their tensile properties with a microstructural evaluation of their fractured surfaces. The tensile results reveal the influence of ball-milled Si-rich powdery chips on the cast materials and demonstrate an improvement in tensile properties for 10% (R = 0.1) and 25% (R = 0.25) addition of reinforcement particulates. The combined effect of processing and the presence of Si-rich particulates is identified on the fractured surfaces. The results also show that higher values of tensile stress and Young’s modulus are obtained for the R = 0.1 samples but that the strain was higher for the R = 0.25 samples. A mechanism and model for the tensile fracture, and particle and interface cracking are proposed according to microstructure and EDX observations.