Microstructure and mechanical properties of SiCp/ZL105 composite prepared by electromagnetic stirring

Aluminum matrix composites reinforced with SiC particles (SiCp) were prepared by electromagnetic stirring. This article aims to study the effects of SiCp addition on microstructure and mechanical properties of SiCp/ZL105, finally leading to expended range for ZL105 alloy application. Microstructural studies were carried out by optical microscope, scanning electron microscopy, and energy dispersive spectrometer. Tensile and hardness tests were conducted in order to identify mechanical properties. It was found that addition of 1.5 wt% SiCp causes the refined microstructure (including primary α-Al and eutectic Si) and reduced secondary dendrite arm spacing of α-Al matrix (12.6 μm). Compared to the ZL105 alloy, the ultimate tensile strength, elongation, and hardness of the composite with 1.5 wt% SiCp were increased by 24.6%, 37.3%, and 27.0%, respectively. The improved mechanical properties can mainly be attributed to the refinement of primary α-Al and eutectic Si, and uniformed dispersion of SiCp. Furthermore, the effects of voltage and agitation frequency of magnetic field on microstructure of composites were discussed.