Abstrak


The Effects Of Thickness Filler On The Physical and Mechanical Properties Of The Dissimilar Metals Resistance Spot Welded Between AL 5083 and SS 400


Oleh :
Triyono - 197406251999031002 - Fak. Teknik

The Effects Of Thickness Filler On The Physical and Mechanical Properties Of The Dissimilar Metals Resistance Spot Welded Between AL 5083 AND SS 400

Abstract

The dissimilar metals joint between aluminum and steel is an alternative method to reduce the weight of vehicle for energy saving in automobiles. The dissimilar metals weld joint is more complex than similar metal weld joint because of the differences in electrical, thermal and mechanical properties of the base metals. Pressed mixture of steel and aluminum powder was used as intermediate material to hold the different properties of joined materials. The aim of this research is to investigate the mechanical and physical properties of spot weld of dissimilar materials due to varied filler thickness. Lap joints of Aluminum alloy Al 5083 with thickness of 4.0 mm and 1.3 mm thick mild steel SS 400 were made using the same resistance spot welding schedule with current, weld time and electrode force of 7 kA, 20 cycles and 6 kN respectively. The filler thicknesses of 0.3 mm, 0.5 mm, 0.7 mm and 0.9 mm were used in this study. The mechanical properties were determined with respect to the shear load bearing capacity and hardness while physical properties were examined based on the macro and microstructure. The highest shear load bearing capacity was found on joint with filler thickness of 0.9 mm. Due to non heat treatable aluminum, there was no significant change of microstructure and hardness in HAZ and weld metal of Al 5083. Ferrite and pearlite structure appeared in HAZ of mild steel while weld nugget had bainite structure.

Keywords: Resistance spot welding, dissimilar metals weld, shear load bearing capacity, aluminum, steel