Effect of friction stir welding parameters on mechanical properties of aluminum alloy to austenitic stainless steel lap joint

Friction stir welding is a solid state welding processes due to the low temperature in the welding zone, prevent formation of defect that can occur during fusion welding. In this paper, the effects of three important parameters of rotational speed, welding speed and tool tilt angle on mechanical properties lap joint of aluminum alloy to austenitic stainless steel have been studied. The results showed that higher increasing the rotational speed or decreasing the welding speed can be cause the creation of defects such as created flash around the weld zone, cavity and sheet thinning defect which will strongly affect on the mechanical properties of the joint, So that maximum fracture load was obtained 7750N in the rotational and welding speed,1000rpm and 80mm/min, respectively which the rotational speed to 2000rpm led to reduce the fracture load of joint to 3350N. It also became clear that strength of the joint increases and then decreases with increasing tool tilt angle. Therefore, that with increases tool tilt angle from 1.5 to 2.5 degree, fracture strength reduce from 7750N to 4180N. Which due to increase of the heat input, create flash around the weld zone reducing the volume of material under the tool shoulder, and finally the formation of defects in the joint.