Investigation of Mechanical & Thermal Properties of Pulsed Current Micro Plasma Arc Welded Aluminum (Al-6061) Alloy

In the present work pulsed current Micro Plasma Arc Welding (MPAW) process is used to join 0.5mm thick sheets of Aluminium (Al-6061) alloy by selecting proper welding parameters namely peak current, base current, pulse rate and pulse width are the most influencing parameters affecting the quality of the weld joint. Trial experiments are carried out using the selected welding parameters to fix the number of levels of each welding parameter. For four factors and five levels, Taguchi L25 orthogonal design matrix is adopted to find the number of experiments to be performed. The mechanical properties such as grain size, hardness and tensile strength are measured as per ASTM standards. Empirical mathematical model is developed for the above weld quality characteristics using MINITAB 20 statistical software considering significant coefficients. Linear equation is adopted in designing the models. The adequacy of the models is tested by Analysis of Variance (ANOVA) at 95% confidence level. The coefficient of determination for the developed models is found to be 0.92. Confirmation experiments are performed to validate the developed models. Lastly, the temperature distribution in the welding sample has been simulated by using ANSYS software. The thermal profiles in different welding zones have been studied in detail and linked to the mechanical properties of the joint.