Effect of Phase Formation on Mechanical Properties of the Joint AA6061 to AA2024 by TLP

In this research, diffusion bonding was employed to joint AA2024 and AA6061 alloys. To select the alloy material of the interlayer, the atomic diffusion of tin, zinc, and gallium elements was modeled at a concentration of 90.1 wt % in pure aluminum. According to the modeling results, tin was selected as the main element of the interlayer alloy. Diffusion bonding was carried out in a tube furnace at a heating rate of 5°C/min under vacuum (7.5 × 10^–3 Torr) and the temperature of 453°C for 210 min for Sn–5.3Ag–4.6Bi interlayer. This experiment was performed considering one interlayer with different thicknesses (20, 50, and 70 µm). Joints were assessed by SEM, and elemental mapping. Ag₃Al, Mg₄₅Al₄₀Ag₁₅ inter-metallic compounds, Sn-rich in solid solutions, and Sn + Cu₆Sn₅ phase were formed at the joint site of the interlayer. The maximum tensile strength of the samples with a joint thickness of 20 µm was 52 MPa after 210 min. By the increase of the Sn–5.3Ag–4.6Bi interlayer thickness (20–70 µm), the average unit tensile stress showed a decline. The effect of the interlayer thickness (20, 50, 70 µm) was investigated on the hardness, strength, and particle size as well as the joint phases.