Revealing the correlation of microstructure configuration and mechanical properties of Al–Si–Mg alloy reinforced by C-doped TiB₂ and SiC

A new Al–Si–Mg alloy was prepared and refined by C-doped TiB₂ (C-TiB₂) and strengthened by SiC, and the effects of microstructure configuration on the mechanical properties of the alloys were investigated in this study. The results show that the eutectic Si and reinforcing particles distribute in a network configuration in the cast Al–Si–Mg alloy with globular grains. In addition, the distribution of the eutectic Si and reinforcing particles is streamlined along the extrusion direction after hot extrusion. The streamlined distribution of eutectic Si and reinforcing particles is beneficial to the ductility of the alloy, the elongation of which is almost twice that of the Al–Si–Mg alloy with a network configuration that possesses higher strength. The reinforcing phase with a network configuration can better withstand the stress and prevent the deformation of the matrix, thus improving the strength of the alloy. By contrast, the reinforcing phase with a streamlined configuration provides conditions for the plastic deformation of the matrix and hinders the contact of microcracks in the matrix, which increases the elongation of the alloy.