Dissimilar Aluminum Alloy Sheet Automatic Twin Wire Welding

The welding process of dissimilar aluminium alloy 5083 and 6061 with 5mm thickness was studied by automatic twin-wire MIG welding. The range of welding process parameters which was suitable for the process of one-side welding with back formation was obtained. The best synthesis of various process parameters is educed by using the Robust Design to optimize welding process and the statistical analysis of the Signal Noise Ratio in the experimental evidences. The results of the proven test accorded with the analysis,and it showed that the stability of the process parameters was excellent. Appearance inspection,microstructure observation, EDAX analysis and property inspection of the welding joint showed that the molding of the two sides of welding line was good. There was no defect in the welding line. The heat affected zone(HAZ) of the welding joint was narrow. And the joint strength could reach 178 MPa which was 74.2% compared with that of base metal.On the base of Robust Design, the Regression Analysis was adopted to establish the multiple linear regression mathematical models related to the width of HAZ on welding joint in side of 6061, welding current, welding voltage and groove angle. The analysis of variance showed that there is a linear dependence relationship between various parameters and the HAZ width. It proved that the multiple linear regression equation was available. The results could be applicable to the joint strength forecast and control of the aluminium alloy using automatic twin-wire welding.