Friction Stir Processing of AA 7039 Alloy

Abstract

Friction stir processing (FSP) is an effective solid state surface modification technique used to improve the surface properties of metals like aluminium, and titanium controlled structural refinement. In present work, friction stir processing of 5 mm thick plate of Al-Zn-Mg alloy (AA 7039) was carried out using a conical pin and overlap of 50%. Modified surfaces were characterized in respect of macrostructure, microstructure, hardness and tensile properties. It was observed that friction stir processing refined the microstructure of AA 7039 alloy and increased the ductility (%elongation). However, tensile strength and hardness were found to be adversely affected. Hardness has been found to be increased with number of passes during friction stir processing.