Investigation of mechanical and microstructural properties of AZ31/SiC nanocomposite fabricated by squeeze stir casting

In this paper, AZ31/SiC nanocomposite was fabricated using squeeze stir casting method. 1 wt% SiC nanoparticles were added to the matrix using a novel powder injection system. The melt was stirred by two different speeds (430 and 600 RPM). The nanocomposite was solidified under the 80 MPa pressure. Some of the samples were cooled rapidly by water and some others were normally cooled by ambient air. Mechanical and microstructural properties of the fabricated nanocomposites were investigated. The results show that the controlled injection of nanoparticles using the gas can enhance the wettability and uniform distribution of nanoparticles. Moreover, increasing the stirring speed and cooling rate led to decreasing the grain size, increasing the uniformity of microstructure and improvement of mechanical properties. In the appropriate situation the yield stress, ultimate stress, elongation and micro hardness were increased by about 72%, 80%, 63% and 11%, respectively in comparison with monolithic AZ31 alloy.