EXPERIMENTAL INVESTIGATION OF EFFECT ON DIFFERENT ROT A TIONAL AND WELDING SPEED FOR FRICTION STIR WELDING (FS W) TEE-LAP JOINTS AA 5083

Abstract

Friction Stir Welding (FSW) is a solid state thermo mechanical joining process and consolidates the metals without reaching its melting temperature. It has been classified as an advanced welding method and a green process. The amount of heat produced by the suitable rotational and welding speed during the process was determining the quality of the joining. The objectives of this research are to investigated and analyzed the effects of the different temperature in different welding parameters on the quality of the AA 5083 joining. This research involved in designing and fabrication of the fixture to fixed on the universal milling machine to conduct the FSW experiments in tee- lap joint configuration. The experiment had been conducted in different tool rotational and welding speed conditions. The samples had been observed to investigate and analyze the effects on the welded area. The result has revealed that the different temperature during welding process directly gives a great impact on the strength. The indecorous welding parameter produced excessive or insufficient heat during the joining process. Hence, the inappropriate heat during the FSW process produced defect and weakened the joining due to insufficient metal transfer to complete the stirring process around the pin tool. Similarly, the excessive heat during the joining process was produced a weaker joining due to the widening of the Heat Affected Zone (HAZ) and deterioration of the grain structure in the material properties around the joining area. The result showed that the sample welded by the parameter 910 RPM@ 16 mm/min, exhibited the best quality of the joining and produced the highest result of Ultimate Tensile Strength (UTS) when the sample was fractured after reaching 198.319 MPa which is equivalent to 66.1 % of the UTS of the Parent Material (PM). The FSW standard requirement where the percentage of the UTS of the FSW joining must exceed 60% of the UTS of the PM was satisfactory (Valate et al. 2016).