Effect of Welding Process Parameters on Mechanical Property of FSW Lap Joint between Aluminum Alloy and Steel

Abstract

This paper investigated the effect of a tilt angle and a pin diameter of the tool on the tensile shear load of lap joints between A5083 aluminum alloy and SS400 steel produced by Friction Stir Welding. The main results obtained are as follows:The joint shear strength could not be increased with the increase of a tool tilt angle due to the formation of intermetallic compound at the joint interface. The increase of a tool tilt angle caused the concentration of aluminum in the intermetallic compound increased, resulting in the decrease of the joint strength. The increase of a pin diameter of a tool also could not increase the shear strength of the joint due to a void defect and a thicker intermetallic compound formed at the interface. The size of the void increased as the pin diameter increased. The effect of a prehole, which was opened at the pin inserting position of an aluminum plate before welding, was investigated to obtain the higher shear strength of the joints. It was concluded that the joint interface temperature was slightly decreased and the thickness of the intermetallic compound at the interface decreased with the increase of pre-hole diameter. The optimal pre-hole indicated the shear strength of about 77% that of the aluminum base material. The interface microstructure examination showed no intermetallic compound was formed at the joint interface.

Microstructure and fracture behavior of friction stir lap welding of dissimilar metals

“…Fig.4 is the first example and a mixed stir zone (MSZ) commonly observed (e.g. Chen & Nakata (2009), Kimapong & Watanabe (2005b)) is shown between the top Al plate and the bottom steel plate. The area of MSZ largely corresponds to the area of the pin penetrated in to steel (in a 2D cross section) and this zone is a mixture of Fe-Al intermetallic thin pieces embedded in the recrystallized α-Fe grains.…”

Microstructure and Tensile Strength of Butt Joint between AA6063 Aluminum Alloy and AISI304 Stainless Steel by Friction Stir Welding

“…Kimapong and Watanabe [6] welded the butt joint between A5083 aluminum alloy and SS400 steel and reported the tensile strength of the butt joint that was about 86% of the base aluminum tensile strength. These researchers also welded the lap joint of between A5083 aluminum alloy and SS400 steel by various FSW parameters and reported that the main effect that decreased the joint strength was the IMC thickness of the joint interface [7,8]. This IMC formation was also observed at the weld metal of Al6061 aluminum alloy and AISI1018 carbon steel and could be classified as Fe 4 Al 13 and Fe 2 Al 5 IMC but no relation between these IMCs phases and the joint strength was reported [9].…”

A Correlation between the Ultimate Shear Stress and the Thickness Affected by Intermetallic Compounds in Friction Stir Welding of Dissimilar Aluminum Alloy–Stainless Steel Joints

“…However, for an optimal thickness, intermetallics provide good bonding characteristics as long as the layer remains compact. Previous studies therefore aim to determine the existence of an optimal intermetallic layer thickness as far as the mechanical properties are concerned [17].…”