Estimation of the Mechanical Properties and Temperature Distribution in Friction Stir Welding Technique of Aluminum Alloys

Friction stir welding of AA 7020-T6 aluminum alloys, 5 mm thick plate is an Al- Zn-Mg grade alloy of 7XXX series heat treatable of medium strength alloys and employed for welded engineering structural components. The effect of FSW parameters (rotational speeds and travel speeds) on joint strength and welding zone dimensions have been investigated experimentally. Four different rotational speeds are used: 450, 560, 710 and 900 r.p.m. with three travel speeds 16, 25 and 40 mm.min-1 The experimental investigation included tensile test and weld pool geometry determination. It was found the that best welding conditions for FSW was the weldments which have 247 Mpa yield strength, 340 MPa ultimate tensile strength, 7.3% elongation, 11020N bending forces for both face and root and hardness value ranging from (133-138) Hv 0.05 for the different welding regions under the optimal welding conditions at a rotational speed of 900 r.p.m. and travel speed of 25mm.min-1.