الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 102 |  |  |
| | | from | 102 | | |
Abstract
For investigate effect of eccentric shoulder on this method ,samples were6mm thickens welded with tow tool first was eccentric shoulder0.2 mm and the second without eccentricity both with tilt angle 3 ◦and zero angle ,and rotation speed was remind at 600 r.p.m ,welding speed(travers speed) were 150,200,250mm/min and shoulder plunge depth 0.2 mm.
The testing witch done were tensile strength, hardens, microstructure with optical microscope.
The grain size in the WNZ is refined to approximately 1.63μm, representing the smallest size achieved. Nonetheless, upon utilizing the aligned shoulder in conjunction with identical welding parameters, the grains within the weld nugget zone (WNZ) exhibit coarsening of approximately 2.79 μm. In contrast, the utilization of eccentric shoulder at a 3º tilt angle yields grains of approximately 2.78 μm, whereas the use of aligned shoulder at the same tilt angle results in grains of approximately 2.23 μm in size. The FSW joints that are produced by eccentric shoulder and a tilt angle of 0 exhibit the most superior mechanical characteristics. Specifically, the ultimate tensile and elongation values of these joints are 216.5 MPa and 7.71%, respectively, which align with the hardness curves. Based on these results, we suggest the optimal tool design for FSW parameters: The utilization of an eccentric shoulder tool design can prove to be highly effective in cases where tool tilt angle cannot be applied for the Friction Stir Welding (FSW) process. Alternatively, the implementation of tool tilt angle in the Friction Stir Welding (FSW) process may prove to be efficacious through the utilization of an aligned shoulder tool design.