The effect of pouring temperature and surface angle of vortex casting on microstructural changes and mechanical properties of 7050Al-3 wt% SiC composite

In this investigation, the effect of pouring temperature and the surface angle of vortex casting on microstructural evolution and mechanical properties of 7050Al-3 wt%SiC composite was studied. Two pouring temperatures of 700 °C and 800 °C were employed during the vortex casting. As well, two surface angles of 45° and 90° were used for the vortex casting. Cast microstructures were analyzed by Scanning Electron Microscope (SEM), Transmission Electron Microscope (TEM), and optical microscope. Mechanical properties were measured by uniaxial tensile test, Vickers hardness and Charpy impact test. Microstructural studies showed a uniform distribution of SiC particles in the 7050 Al matrix is achievable by increasing the pouring temperature from 700 °C to 800 °C and also by decreasing the surface angle from 90° to 45°. This uniform distribution of particles was coincided with the breaking of the dendrite arms in the microstructure of 7050 Al-3 wt% SiC. Mechanical properties measurements showed that the yield strength, hardness and fracture energy of the composite were increased by increasing the pouring temperature and reducing the surface angle during the vortex casting.