Effects of post weld heat treatment (PWHT) on mechanical properties and microstructure of EN AW-6082 T6 aluminum alloy

Abstract

The issues which appears at fusion welding of 6082 T6 aluminum alloy are connected with hot cracking (solidification and liquation crackings), porosity and over aging of a portion from heat-affected zone (HAZ). Relatively high thermal expansion and the wide range solidification temperature of the Al alloy are the main causes of susceptibility to welding cracking. Moreover, over aging phenomenon of a portion from HAZ, due to the welding thermal cycle is manifested by the decrease in hardness and mechanical strength of the welded joint. The main objective followed by this paper is to restore the microstructure and the mechanical properties of the pulsed MIG welded joints made from 5 mm thickness sheets by applying a post weld heat treatment of solution quenching followed by artificial aging.