Process Parameter Optimization of Aerospace-Grade Dissimilar Aluminium Alloy 7075 and 2014 by Friction Stir Welding

Abstract

In friction stir welding process, the selection of optimum process parameter is an important step. To make a welding with high quality in all aspects such as defect free and reduced HAZ region, it becomes necessary to choose the parameter in such a way the temperature developed due to heat generation is in optimum level. A study on the effect of process parameters on temperature distribution and HAZ region is performed for dissimilar combination of AA7075 and AA2014. A statistical model based on Box-Behnken RSM is built to study the interaction effect of parameters on temperature distribution and optimization of process parameter is obtained as is Tool Rotational Speed (TRS) – 1400 rpm, Tool Traverse Speed (TTS) – 1.21mm/s and Tool Size Ratio (TSR) – 4. An experiment of FSW is made with K-type thermocouples for optimized parameter of AA7075+AA2014 and temperature reading is then compared with simulation for validation of model. The prediction accuracy is in the range of maximum 98.69% and minimum 92.45%. It was observed that optimum depth location of thermocouples is beyond the half of thickness because of less error attained as 1.31%.