Microstructure and Wear Rate of Yttria Reinforced Aluminum – Silicon Matrix Composites

Abstract

In this research, composite materials of hypereutectic aluminum – silicon as a matrix reinforced with different volume fractions (2%, 4%, 6%, 8%) of Yttria particles with grain size between (50 - 75 μm) are prepared. The composites are prepared by vortex technique in which the particles were added to the melt then mixing it by mechanical stirrer then the mixture is poured in a metallic cylindrical molds. After that, the microstructure, Vickers hardness and wear rate were conducted. The results showed the existence of the reinforcement particles indifferent amounts in the microstructure and an increase in the hardness for the prepared composites when compared with the unreinforced alloy. The results also showed a better particles distribution and higher hardness with increasing yttria volume fraction. The wear rate of the composites is reduced when compared with the unreinforced alloy due to the hardness increase. More reduction in wear rate was noticed with increasing the Yttria volume fraction, and the better added percent was (8%Y2O3).