Enhancing the Microstructure and Tribological Performance of Spray Formed Al Alloy by Cryorolling

Abstract

In the present study, the microstructure and tribological performance of Al alloy has been enhanced by cryorolling. The Al-6 wt.% Si alloy has been selected as Al alloy which has been prepared by spray forming technique with 400 mm flight distance. Developed spray formed Al alloy has been subjected to cryorolling with different thickness reduction (25% and 50%) on non-reversing rolling mill using liquid nitrogen. The alteration in microstructure and tribological properties has been studied by different techniques. The microstructure results indicate that the cryorolling process refines the size of aluminium rich phase and silicon particles of spray formed Al alloy. The tribological testing results illustrate that the wear rate of Al alloy decrease by cryorolling. While the cumulative volume loss and wear rate increase with an increasing sliding distance and applied load for spray formed and cryorolled Al alloy. The coefficient of friction exhibits a fluctuating action with sliding distance while it decreases with an applied load and cryorolling. The worn surfaces have also been analyzed under scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS) and atomic force microscopy (AFM) techniques to study the operative wear mechanisms. Hardness property and microscopic analysis of Al alloy have also been correlated with tribological properties.