Effect of Pouring Temperature in Al-16Si-1%Al2O3 Hypereutectic Alloys

In Al-Si hypereutectic alloys, the mechanical properties are affected by grain size, volume fraction and distribution of both primary as well as eutectic silicon. The instantaneous refinement and modification of primary and secondary Si particles in hypereutectic Al-Si alloys are very difficult through conventional processes. This paper investigates the effect of pouring temperature on Si particles during solidification in hypereutectic Al-16Si-1%Al2O3 alloys at particular rotation speed. It has been reported that the interfacial bonding between the dispersed phase and liquid matrix was good in the synthesized composites achieved in order to provide improved mechanical properties. The wear behaviour and hardness of the cast product of hypereutectic Al-16Si alloy significantly varies at different pouring temperatures. The dry sliding wear test has been performed on a group of specimens with varying parameters (at different temperature with different load and sliding velocities) in a pin on disc wear testing machine. However in XRD analysis of the samples depicted the formation of brittle phases like SiO2, Al2O3 and Al-rich intermetallic compounds. The hardness value of the materials increases with increasing pouring temperature where as it was again decreases with increasing higher pouring temperature.