Case Study On Friction Stir Welding

I. INTRODUCTION rom last some years, world focus on developing efficient and environment friendly metal joining processes. So, for joining two materials focus on Friction Stir Welding (FSW) is increased now. FSW developed by W. Thomas at TWI in 1991.FSW is advance welding technology and has emerged as a solid state joining process which used to join that material which is difficult to join by fusion welding processes. This technique is use in aerospace, shipbuilding, automobile industries. The basic concept behind the FSW process is that, after matting the two weld edges, non-consumable rotating tools is plunge between them and gives feed to it along the weld seam. The metal is extruded from the base plate around the tool before being forged

They characterized in terms of thickness, hardness, adhesion and tribological behavior for uncoated pin tools. The Increase of wears observed in second stage.
Baskaran A, K.Shanmugam K and Balasubramanian V [4] studied the effect of hard faced tools. HSS, MWC, PWC tools hard faced with powder composition of 60% WC & 40% NiCrBSi. HSS tool produced surface defects but MWC tool welded copper alloy without surface defect but threaded pin profile was worn out completely. Kundzanayi Chiteka[5] denoted in the proves of FSW tool material selection that High Carbon High Chromium (HCHCr) Tool Steel has high wear resistance when AA5083-H111A1 Alloys was welded.
Dr A.K.Shaik Dawood and M.Karthikeyan [6] used Aluminum alloy AA6351as base material and tools of pin profile Circle, Thread and Square with D/d ratio of 3.HSS is chosen as tool material because of its high strength and high hot hardness, easy to process, easy availability and low cost. The welding performed at 1350rpm and welding speed 75mm/min and found that tool pin profile square tool wears the

Rubtsov, E.A. Kolubaev [21] annealed aluminum alloy sheet 5 mm thickness sheets have been welded using a FSW machine. Structurally it consists of aluminum / magnesium solid solution and inclusions basically being Mg2Si and Al6Mn. The FSW tool had shoulder's diameter 19 mm and pin's diameter 6 mm. Weld path lengths was 2000 mat 560rpm, plunge force 2600 kg, feed rate 500mm/min. SEM instrument has been used for detecting the chemical composition of the FSW tool and tribological layers. Tool wear is of different cross sections after welding
B.Thopmson and S.S. Babu [22] studied tool degradation characteristics in the Friction Stir Welding of hard metals. They studied pre- and post microstructures of three tungsten based tools. The tool composition and obtained result are as follows: - Material A (99% W, 1% La2O3) degraded by severe plastic deformation, Material B (75% W, % Re) degraded by twinning and Material C (70% W, 20% Re, 10% HfC) degraded by intergranular failure.
IV.