Prediction of bead geometry parameters in MIG welded aluminium alloy 8011 plates

Abstract

In today's fabrication industry, the MIG (metal inert gas) welding procedure is widely employed because of its versatility, adaptability to automation and good quality welds in a majority of engineering materials. Weld bead geometry of a weld determines its strength, mechanical properties and its performance during service life. It is therefore imperative to optimise these parameters for a reliable weld. An attempt is therefore being made in the present work to find a mathematical connection between the important bead Input parameters including wire feed rate, voltage, welding speed, nozzle to plate distance, and torch angle, and depth of penetration (DOP), weld width (W), height of reinforcement (HOR). The design matrix for the tests was created using the statistical approach of central composite rotatable design (CCRD). The analysis of variance (ANOVA) approach was utilized to evaluate the adequacy of the obtained equation, and response surface methodology (RSM) was employed for graphical interpretation of the findings. Weld bead geometry deeply influences the mechanical strength and quality of the welded joint; therefore it must be of the required dimensions. It has been found that bead geometry depends upon the value of input parameters. To get the desired values of the bead parameters, an optimal combination of input parameters was found.