EFFECT OF TOOL PIN PROFILES OVER SQUARE WAVE TOOL PATH PATTERN ON FRICTION STIR WELDING OF AA6061-CU DISSIMILAR ALLOYS

Abstract

In this present work friction stir welding of Al6061-annealed pure copper dissimilar metals with square wave pattern tool pin movementwas investigated.  The aim of this experiment is to identify the significance square wave tool movement on friction stir welding process along with three different tool pin profiles. Different tool pin profiles of square, round and hexaspiral shapes were selected and their significant outcomes were unveiled. Friction stir welding process parameters of 1500 and 2000rpm & tool pin movement step size of 1.0mm and 2.0mm & weaving rate of 100mm/min and 150mm/min were selected. The advantages of tool movement pattern and tool pin profile shape wereexamined by mechanical testing, microstructure analysis. The mechanical results were showed that process parameter of 1500 rpm, 1.0mm step size, weldingrate of 150mm/min and square tool pin profile combination gives better mechanical properties. Micro structural results unveiled achievement of better grain refinement and uniform dispersion of micro constituents by implementation of square wave tool pin movement pattern along with square tool pin profile.The EDAX report confirms that the weld nugget contains both aluminum and copper as equal percentage, which indicates fine mixing of two parent metals.