Effect of Rare Earth Element Nd on the Microstructures and Properties of Hypoeutectic Al-Si Alloy

Different contents of Nd were added into the hypoeutectic Al-Si alloy ZL101 in the form of master alloy for modification. The microstructure, mechanical properties, tensile fracture morphology and phase composition of alloys before and after being modified were investigated. The results indicate that ZL101 alloy was modified by the addition of Nd; the hardness, tensile strength and elongation of the modified alloy were increased first and then decreased, the optimum mechanical properties with hardness of 72 HBS, tensile strength of 190 MPa and elongation of 2.9% were achieved when 0.3wt% Nd was added into the alloy; and dimples were observed in the tensile fracture morphology; Nd compound phase, Al8Si8MgNd2, formed when the content of Nd was 0.4wt%.