The Effect of Microstructure and Mechanical Properties of Aluminium Aa6061 before and after Heat Treatment Using TIG

Abstract

This work studies the effect of a post-weld heat treatment (PWHT) on the mechanical and microstructure properties of an AA6061 sample welded using Tungsten Inert Gas (TIG) method. TIG method is comparatively flexible and has good economy. The welded samples were divided into as-welded and PWHTs samples. The PWHTs samples were solution heat treatment, water quenching and artificial aging. Both welded samples were cut according to the ASTM E8M-04 standard to obtain the tensile strength and the elongation of the joints. The failure pattern of the tensile tested specimens was analysed using scanning electron microscopy (SEM). A Vickers microhardness testing machine was used to measure the hardness across the joints. From the results, the PWHTs were able to enhance the mechanical properties and microstructure characteristics of the AA6061 joints welded by the TIG method.