Microstructure and fracture behavior of friction stir lap welding of dissimilar AA 6060-T5/ Pure copper

Abstract

This study aims to understand the uncertainty about the optimum or best pin position (Dp) for friction stir lap welding (FSLW) of Al-Cu. Tensile shear testing is used to determine the Mechanical strength of FSL welds under static loading. Fracture strength (σLap) corresponding to the maximum load in a test over the sample width is used as the strength value. Interface microstructures differ depending on whether the tool pin penetrates the lapping interface. It has been found that σLap values of the defect free weld samples vary quite significantly and in general are significantly higher than those reported in the literature. When the pin penetration is close to zero no intermetallic layers were formed, hence the value of σLap was zero. When the pin penetration is 0.4mm, the commonly observed a thin Al-Cu interface layer forms and this layer does not grow beyond 3µm. It is shown that the thin interfacial layer can withstand a high tensileshear load and thus the adjacent Al material shears to fracture. When the pin penetrates more than 0.4mm, the commonly observed mix stir zone (MSZ) forms and values of σLap are lower than that of 0.4mm pin penetration welds but remain quite high.

The Microstructure and Mechanical Properties of Multipass Friction Stir‐Welded Al/Cu Lap Joints and Interface Transfer during Butt Joining of Thick Plates

“…Tensile shear testing of overlap welds has been the major method used for evaluating strength of FSW overlap welds in literature. [28] Figure 2a shows the sampling configuration of the tensile shear samples on the joint, in which the sample was cut parallel to the welding direction, and two notches were carefully cut out on the welded Figure 1. The schematic diagram of the Al/Cu FSW shown as: a) the lap FSW and the interface transfer during the butt joint of the thick plate and b) the stir tools.…”

“…Tensile shear testing of overlap welds has been the major method used for evaluating strength of FSW overlap welds in literature. [ 28 ] Figure a shows the sampling configuration of the tensile shear samples on the joint, in which the sample was cut parallel to the welding direction, and two notches were carefully cut out on the welded aluminum and copper to ensure that entire shear load was applied on the joining interface. For the butt joints, tensile specimens according to ASTM‐E8M were cut from welded plate perpendicular to the weld line that the joint was in the middle of the specimens, as shown in Figure 2b.…”

Investigation of the effect of welding and rotational speed on strain and temperature during friction stir welding of AA5083 and AA7075 using the CEL approach

“…Dissimilar joining strives to increase the effectiveness and performance of the connected components by fusing the metal properties [14]. Due to the importance of quality and good mechanical properties in the welded products made by the friction stirring concept, several researchers have studied the effect of welding parameters on common mechanical properties, including tensile strength, microstructure, and hardness values in similar and dissimilar joints [15][16][17][18]. Some other researchers have studied the cracking resistance, fracture toughness, and load-carrying capacity of FSW joints in the presence of a macro crack in the joining region [19].…”

Investigation of Friction Stir-Welded B4C Particles-Reinforced Copper Joint: Mechanical, Fatigue, and Metallurgical Properties

“…e dissimilar joints produced from FSW are used for aerospace applications [5][6][7]. Defect-free welded joints were produced in Cu and steels by FSW using different tool shoulder diameters.…”