Effect of Sodium Modifier on the Microstructure and Wear Rate of Al-14 Wt%Si Alloy


In this study, a demonstration of the effect of Na addition to themicrostructure and wear rate of hypereutectic Al-14 wt% Si alloy was carried out. It isfound that the addition of Na has an important effect on shifting the eutecticcomposition of Al-Si alloys from approximately 12 wt% to 14 wt% Si; shifting theunmodified alloy from hypereutectic to eutectic alloys for the modified alloys. Themodified alloys have a eutectic composition with fine needle at lower Na content(0.05 wt%). Increasing the percentage of Na to 0.12 wt% resulted in producing alamellar Si structure compared with acicular structure for unmodified alloy. The wearrate of modified alloys is lower than the hypereutectic alloy. Wear rates observedwere in the range of 10-9 to 10-11 which is fully identified in the mild wear rate regime.