Effect of tin on the structure, mechanical and tribological properties of sintered Al-12Si alloy

The structure, mechanical and tribological properties of composites produced by sintering of mixtures of Al-12Si alloy and tin powders were investigated. The sintering of the briquettes was carried out in a vacuum at 570 °С after their preliminary exposure at 550 °С for one hour. It was established that liquid-phase sintering on the specified regime makes it possible to obtain the (Al-12Si)-xSn composites with continuous aluminum matrix in a wide range of tin content. The final porosity of the samples remained practically unchanged with increasing sintering time, but the ductility of the composites was improved. In order to eliminate the residual porosity the (Al-12Si)-xSn composites were subjected to hot densification at temperatures above and below the melting point of tin. It was found that the temperature of hot densification has little effect on the strength of the composites. The value of the strength is determined by the rule of the ideal mixture. Whereas the wear resistance under dry friction of the densificated composites improves with increasing tin content. This effect is especially noticeable at high loads.