Metal Inert Gas (MIG) Welding Process Optimization for 6063-T6 Extruded Material Using OTC/Diahen Equipment

Joining methods for spaceframe architectures using extruded structural elements are getting popular. At present, the development of lightweight vehicles, in particular aluminum intensive vehicles, requires substantial development of manufacturing processes for the joining and assembling. Joining methods, such as electric arc resistance, and laser beam fusion welding together with nonfusion ultrasonic welding rise as possible alternatives for high volume joining of aluminum. In this study, metal inert gas (MIG) welding was used to join heat treatable extruded 6063 T6 aluminum alloys. The purpose of this study was to find optimum MIG welding parameters for joining 6063-T6 extruded aluminum. Also, the MIG welding equipment used in this study is OTC TP 350 DF weld power supply and DR-4000 robotic system. The welding process factors considered were power input (voltage, current, and torch speed), pulse frequency, gas flow rate, torch angle and arc intensity. A partial factorial design of experiment (DOE) was conducted to understand the main and interaction effects on joint load to failure and weld geometry. Post weld analysis indicated power input is the most statistically significant factor and the main contributer to joint load to failure. Weld throat was mainly affected by power input, pulse frequency and the interaction between power input and pulse frequency. Based on lap shear test and weld geometry data analysis, optimum weld schedules were determined.