Effect of grain refinement and modification on the dry sliding wear behaviour of eutectic Al-Si alloys

The present study deals with an investigation of dry sliding wear behaviour of grain refined and or modified eutectic (Al-12Si) Al-Si alloy by using a Pin-On-Disc machine. The indigenously developed Al-1Ti-3B and Al-10Sr master alloys were used as grain refiner and modifier for the grain refinement of α-Al dendrites and modification of eutectic Si, respectively. Various parameters have been studied such as alloy composition, sliding speed, sliding distance and normal pressure. The cast alloys, master alloys and worn surfaces were characterized by SEM/EDX microanalysis. Results suggest that, the wear resistance of eutectic Al-Si alloys increases with the addition of grain refiner (Al-1Ti-3B) and or modifier (Al-10Sr). Further, the worn surface studies show that adhesive wear was observed in Al-12Si alloy in the absence of grain refiner and modifier. However, an abrasive and oxidative wear was observed when the grain refiner and modifier are added to the same alloy. Commercially available LM-6 (12.5%Si) alloy was used for comparison.