Surface Modification of Cast Al-17% Si Alloys using Friction Stir Processing

The scope of this investigation is to evaluate the effect of input process parameters of friction stir processing to enhance the mechanical and tribological performance of the cast hypereutectic Al-17% Si alloy. Towards this end, the workpiece material of Al-17% Si alloy was cast to friction stir processing and the effect of process parameter such as tool transverse speed ( 26, 40, and 60) mm/min, at fixed tool rotational speed 664 rpm on the surface characteristics of the cast Al-Si alloy was studied. The results were compiled by using optical microscope, FESEM, hardness, tensile and EDX analysis. The results shows at the optimal input conditions of friction stir processing, the microstructure of cast alloy has been improved in terms of refinement of eutectic and primary Si particles, uniform distribution of Si and the reduction in porosity. In addition, the hardness and tensile properties were improved, the tensile elongation has been increased from <2 % to about 9 %. (C) 2015 The Authors. Published by Elsevier Ltd.