Effect of process parameters on microstructure and mechanical properties in AlSi9Mg connecting-rod fabricated by semi-solid squeeze casting

The effects of applied pressure, pouring temperature and die temperature on the microstructure and mechanical properties of connecting-rods fabricated by the semi-solid squeeze casting (SSSC) process were investigated. The results show that the non-dendritic primary α-Al particles distribute uniformly throughout the connecting-rods. With the increase of applied squeeze pressure, the size of α-Al particles decreases while the shape factor increases, which increase the mechanical properties of the connecting-rods. When the pouring temperature and die temperature increase, the size and shape factor of primary α-Al particles increase. However, if the die temperature is higher than 300 °C, the shape factor decreases suddenly. The best microstructure and mechanical properties of connecting-rods fabricated by SSSC were obtained at the pouring temperature of 575 °C, die temperature of approximately 250 °C, and squeeze pressure of 100 MPa.