Analysis and optimization of resistance spot welding parameter of dissimilar metals mild steel and aluminum using design of experiment method

Abstract EN

This research aims to study the effect of parameters of the resistance spot welding (RSW) on the shear strength of the spot weld for different metals {AA 6061-T6 and AISI 1010} using (0.5 and 0.7 mm) thickness.

Three values for each welding parameters (welding current, electrode force, squeeze time and welding time) are to be used.

The effect of those parameters have been analyzed by Minitab program by design of experiments (DOE) in order to determine and reduce the number of specimens required to achieve the tests.

The design of experiment method which used was Taguchi method The experimental tests that had been done are shear, Microhardness and microstructure tests.

It was found that the maximum shear force in welding of dissimilar metals (AA 6061-T6 with AISI 1010) is (F = 1.14 KN for t = 0.7 mm ).

This value has been optimized to reach (F =1.24 KN) using DOE.

The minimum shear force was (F = 0.25 KN in t = 0.5 mm).

In general, increasing the welding current and sample thickness gave an increase in the shear force, but at the same time the reduction in shear force have occurred during the increasing in electrode force, squeeze time and welding time.

From Microhardness tests, the maximum value of hardness is found at the center of nugget zone (NZ) and it reduces slightly until reaching constant values away from NZ.