Mechanical properties of rotary friction and gas tungsten arc welded aa6061 weldments subjected to equal channel angular pressing Mechanische Eigenschaften der reib- und wolframinertgasgeschweißten Aluminiumlegierung (AA6061) unter gleichmäßiger Winkelpressung

Abstract

Metal joining can perhaps be said as one of the most indispensable manufacturing processes, with applications across a variety of engineering streams ranging from automobile to day-to-day construction activities. The conventional techniques primarily rely on melting the two joining surfaces and solidifying them to create a fresh cast joint. Though the plates being welded are wrought the joints inevitably are cast and hence result in heterogenous mechanical properties between the base metal. In alloy systems with eutectic phase, the high heat input involved in melting the joining surfaces often degrades the strength of the material in the vicinity of the weldment resulting in the formation of a heat-affected zone. In the welding of heat-treatable aluminium alloys, heat-affected zone degradation is often the weakest point of the welded sample The mechanical properties of a weldment can be improved by extensive plastic deformation. Studies show that such strengthening of AA6061 alloys is a combined influence of the grain refinement of the primary matrix as well as the redistribution of the secondary eutectic phase. Weldments fabricated by gas tungsten arc welding and rotary friction welding were subjected to severe plastic deformation, and the effects were studied. Improved mechanical properties thereby providing an alternative solution to post-weld heat treatment were observed.