Research on microstructure and property of in-situ of Mg_2Si_p/Al composites

The Mg2Sip/Al composites were fabricated with melt direct reaction method.The effect of Mg2Si particle content and heat treatment by solution treatment at 530℃ for 6h followed by artificial ageing at 173℃ for 5h on microstructure and performance of the composites were investigated,the phase contents and the microstructure of the composites were analyzed by XRD,SEM and EDS,and the mechanical properties were then tested.The results indicate that:in a certain range,the grain size of the matrix of the as-cast composites are getting smaller with increasing particle content;the composite with a nominal Mg2Si particle content of 4wt% after heat treatment precipitates more second phase particles than the composite with a nominal Mg2Si particle content of 5wt%,and the average size of second phase particles in both of them are about 4μm.After heat treatment,the tensile strength and the elongation of the composite with a nominal Mg2Si content particle of 4wt% reach 280MPa and 9% which are 24.44% and 63.64% higher than those before heat treatment,respectively.