The effect of yttrium on the microstructure and wear and mechanical properties of Al-20%Sn

Abstract

The current study aimed to examine the effects of different amounts of yttrium on refining the microstructure and improving the wear and mechanical properties of Al-20%Sn alloy. Microstructural analysis indicated that the addition of yttrium led to the formation of an intermetallic compound, Sn5Y2, within the tin phase, disrupting the continuity of this phase at the grain boundaries. Regarding the mechanical tests, it was found that the addition of yttrium increased the hardness and Young's modulus of the alloy. With 1 wt% yttrium addition, the hardness increased by more than 80 %, and Young's modulus doubled. The addition of yttrium up to 0.5 wt% increased the coefficient of friction and erosive wear weight loss, while higher yttrium contents caused a decrease in these values. The friction coefficient in the alloy with 1 wt% yttrium was even lower than that of the initial alloy.