Evaluation of the effect of 4 wt.% Si and 1 wt.% Mg addition on solidification, microstructure, mechanical and wear properties of Al-15Sn bearing alloy

Al-Sn bearing alloys, despite their excellent anti-friction properties, have limited use due to their low-load bearing capacity and low-fatigue resistance. In this study, it has been tried to eliminate some of these limitations by adding4 Wt. % Si and 1 Wt. % Mg elements to Al-15Sn alloy. Thermal analysis of the new alloy showed a eutectic reaction during the solidification path after a primary precipitation and a monotectic reaction. The microstructural evaluations of the new alloy showed a change from a networked Sn phase around the primary α-Al dendrites to the peritectic-type island structure. The results of mechanical tests showed with the addition of Si and Mg, elastic modulus increased about 5.8 times, the compressive yield strength increased about 7.7 times and the hardness increased about 2 times. The results of the wear test also showed an increase in the friction coefficient of about 33% and a decrease in weight loss of about 10%.

Keywords:

Bearing alloy , Al-Sn alloy , Al-15Sn-4Si-1Mg alloy , Microstructure , Thermal analysis , Wear properties