Effect of Precise TIG Welding Pool Temperature Control on Microstructure and Mechanical Properties of 7072 Aluminum Alloy Joints

This study investigates the effect of TIG weld pool temperature on the microstructure and mechanical properties of crack-repaired joints in 7072 aluminum alloy. To address poor temperature stability and slow response in indirect temperature control during TIG welding by adjusting the parameters, a new closed-loop molten pool temperature control method is proposed. Experimental comparisons were conducted to evaluate its effectiveness. The results show that using real-time molten pool temperature as direct feedback allows the welding current to be adjusted dynamically. This approach enables precise control of heat input. It also achieves real-time tracking and stable regulation of the molten pool temperature during welding. Temperature-controlled welding yields a more uniform joint microstructure with reduced porosity. Notably, the joint exhibits optimal comprehensive mechanical properties at 1825 °C, with a tensile strength of 328 MPa and an elongation of 9.9%. Overall, precise control of the TIG weld pool temperature effectively improves the quality and performance uniformity of aluminum alloy crack repairs.