Effects of friction welding conditions on tensile strength of friction welded joint between 5052 Al alloy and pure copper

Abstract

This paper described the tensile strength of friction welded joint between Al-Mg alloy (JIS A5052) and pure copper (OFC). In particular, the joining phenomena during the friction process and the effects of friction welding condition such as friction pressure, friction time and forge pressure on the joint strength have been investigated, and the metallurgical characteristics of joints have been also observed and analyzed. The adjacent region of the weld interface at the A5052 side was upset during the friction process, although that of the OFC side was hardly upset. When the joint was made with a friction pressure of 30 MPa, all joints fractured at the weld interface because those joints had the not-joined region at this portion. To reduce the not-joined region, the joint was made with increasing forge pressure. All joints did not have a joint efficiency of 100% (same tensile strength as the A5052 base metal) and the fracture on the A5052 base metal without crack at the weld interface, although the joint efficiency increased with increasing forge pressure. It was showed that the joint had the mechanically mixed layer as the lamellar structures of A5052 and OFC on the adjacent region of the weld interface at the A5052 side, and that layer influenced to the fractured point of the joint. The mechanically mixed layer decreased with decreasing friction time and with decreasing friction pressure after the initial peak. Then, the joint, which had the same tensile strength as the A5052 base metal, the fracture on the A5052 base metal with no crack at the weld interface, and less mechanically mixed layer with no the intermetallic compound (IMC) interlayer on the weld interface, could be successfully achieved. In conclusion, it was suggested that the joint should be made with a low friction pressures such as 20 MPa to prevent generating of the mechanically mixed layer, an opportune friction time such as 6.0 s without generating the IMC interlayer, and a high forge pressure such as 240 MPa in order to achieve completely joining of the weld interface and the fracture on the A5052 base metal.

Research Progress of Aluminum Alloy Welding/Plastic Deformation Composite Forming Technology in Achieving High-Strength Joints

“…An enormous amount of IMCs appeared in the half-radius zone and the periphery zone, but much fewer IMCs appeared in the central zone [90]. To control the thickness of IMCs, in addition to optimizing the welding process [91], it can be achieved by adding a suitable interlayer to the substrate [92]. and the periphery zone, but much fewer IMCs appeared in the central zone [90].…”

“…and the periphery zone, but much fewer IMCs appeared in the central zone [90]. To co trol the thickness of IMCs, in addition to optimizing the welding process [91], it can achieved by adding a suitable interlayer to the substrate [92]. The grain and second-phase particle evolution of aluminum alloys during frictio welding is also heterogeneous and affects the final properties of the joint.…”

Effect of Rotation Speed on Microstructure and Mechanical Properties of Continuous Drive Friction Welded Dissimilar Joints of 6061-T6 Al and Copper

“…Many process parameters, including rotation speed, friction time, friction pressure, forging time, and forging pressure, will affect the flashes and interface morphology, which determines the mechanical properties of the joint. Kimura et al [23,24] studied the effect of friction pressure, friction time, and forging pressure on the UTS of A5052 Al/pure Cu joints using the CDFW. They found that higher strength-efficient joints can be obtained when using a lower friction pressure, a higher forging pressure, and a proper friction time.…”