Preparation and Properties of Magnesium-Aluminum Matrix Composites Reinforced with Silicon Carbon Particles

摘要

Mg-5wt.%Al alloy based composites reinforced with 0wt.%, 1wt.%, 2wt.% silicon carbon (SiC) particles (average particle size about 3.5μm) were prepared under flux protection conditions. The microstructures, textures, components and hardness of the above composites were investigated through optical microscope, scanning electron microscope, X-ray diffraction and sclerometer. The results indicate that SiC particles are distributed along grain boundaries, limiting grain growth and conducing to the refinement of the matrix. The hardness of composites increases with the increase of SiC particles addition amount. The presences of Mg_2Si and the binary carbide Al_4C_3 were observed in the composites. The Al_4C_3 phase has a crystal structure closer to that of Mg than to that of SiC, which can be act as a potential nucleant for Mg-5wt.%Al alloy.