Effect of Heat Input on the Structure and Properties of Aluminium Weldment TIG Welded with 4043 Filler Rod

A systematic investigation was made on TIG welding of aluminium alloy to improve the structure-property relationship of weldment by controlling heat input. Aluminium plates of 1xxx series were welded with filler metal 4043 and with different current settings 145 A, 175 A and 195 A. The welded samples were examined under optical and scanning electron microscopes and mechanical tests were performed to determine hardness, tensile and impact strengths. An eutectic was found to form. At the highest current setting that is at the highest heat input the eutectic mixture was coarsest and largest in size and tend to form a continuous network. On the other hand at low heat inputs the eutectic mixture did not get sufficient time to grow or to form any continuous network. The change in microstructure with heat input is also supported by the hardness, tensile and impact strength values of these plates.