Experimental Investigations into Immersed Friction Stir Welding of AA2014 T6

Abstract

The recent advancement in various technological fields demands the development and newlineuse of new materials and manufacturing processes. The aluminium alloy is light weight and newlinehigh strength which finds wide spread use in the automobile and aerospace industry. The newlinewelding of heat treatable aluminium alloys has always represented a great challenge for newlinedesigners and technologists since heat provided by welding process is responsible for the newlinedecay of mechanical properties. This decay is due to phase transformations and induced newlinesoftening in the alloy. This can be overcome by employing friction stir welding (FSW) newlineprocess. The advantages of FSW method have encouraged research in welding of aluminum newlinealloys using FSW. Air FSW has been widely used for the joining of the aluminium alloy but newlinein air FSW, the HAZ is wider compared to immersed FSW. Considerable improvement in newlinemechanical properties of FSW joint of various aluminium alloys has been achieved by FSW newlinein immersed condition. In immersed FSW, the workpiece is completely immersed in the water newlineenvironment during welding. newlineThis work has attempted to fill some of the gaps in the contemporary research in newlineimproving the FSW performance of AA2014-T6. Due to a large number of factors and their newlineinteractions influencing the immersed FSW process, the process control becomes complex. newlineThe present work correlates the inter-relationship of various immersed FSW parameters, newlinenamely, welding speed, rotational speed and shoulder diameter on the tensile strength. newlineResponse surface methodology (RSM) has been used to develop the second order model that newlinecan be used to predict the tensile strength in terms of the significant parameters under newlineconsideration. The significance of immersed FSW parameters on the selected response has newlinebeen evaluated using analysis of variance. The developed statistical model further utilized to newlinefind out the optimum parameters for maximum tensile strength using a Genetic Algorithm newline(GA). newlineImmersed FSW has multi performance characteristics, namely tensile stre