Friction Stir Welding of Two Dissimilar Metal Alloy

Abstract

FSW is a solid-state joining process where the original metal characteristics remain newlineunchanged as a whole lot as viable since joining takes place in a plastic state without melting. newlineFSW tool intermixes the metals at the place of the joint, then softens them and fused using newlinemechanical strain. It is most often applied on large pieces of aluminium alloy materials that newlineare impossible and not suitable for further heat treatment to recover its characteristics. newlineThis thesis focuses on the FSW between two dissimilar metal - aluminum alloy AA6061-T6 newlineand a steel 304L. An end mill was modified to perform friction stir welding, and tool made newlinefrom PCBI material have been used for joining these two dissimilar metals . The welding newlineprocess has been carried out by varying the spindle rotation weld speed, and tool tilt angle. newlineA series of friction stir welds has been produced in order to optimize weld/process variables newlineto minimize flaws in the weld and obtain the best possible mechanical properties for AA6061- newlineT6 and a steel 304L. The room temperature mechanical properties have been tested in order newlineto assess the success of the welding process under the different experimental conditions. The newlinetensile strength has been measured to quantify the overall strength of the entire weld cross newlinesection. The heat-treatable AA6061-T6 restores the mechanical properties of the aluminum newlinealloy and improves the mechanical properties of the aluminum-steel joint. newlineAnalysis of experimental data has done by using MINITAB-17 software. The effect of newlinevarious input parameters on output responses has been analyzed using analysis of variance newline(ANOVA) to identify the process parameters that are statistically significant, and which newlineaffect the tensile strength of FSW joints. newlineThe optimized parameters for high ultimate tensile strength AA6061-T6 and 304L joint are newlinetool rotation-700rpm, tilt angle-20 and travel speed of 3mm/min. The friction stir welded newlinesimulated model has been developed for thermal analysis of workpiece and tool.