Effect of Zinc Coatings on Joint Properties and Interfacial Reactions in Aluminum to Steel Ultrasonic Spot Welding

Interfacial Characterization of Dissimilar Joints Between Al/Mg/Al-Trilayered Clad Sheet to High-Strength Low-Alloy Steel

“…Patel et al 20 showed that the maximum lap shear strength of 3.7 kN was achieved in the USW Al5754 to HSLA steel joint with Zn coating. Haddadi et al 26 also reported a maximum lap shear strength of 3.1 kN in the USW joint of Al6111-to-hot-dipped Zn-coated steel and 2.7 kN for the USW joint of Al6111-to-galvanized annealed steel. Because the Al/Mg/Al-clad sheet to HSLA joint with Zn coating separated from the Al/ Mg-clad interface due to the presence of brittle IMC, the bonding strength would be expected to be equivalent to that of Al/Mg-clad interface, which was about 0.5 kN, as reported in our earlier study.…”

“…3d and e). Haddadi et al 26 also reported that diffusion-induced Zn can penetrate along the high-angle grain boundaries. The maximum ingress depth of Zn element into Al-clad layer was $90 lm observed at a welding energy of 1000 J, which was significantly larger than that for a normal solid-state diffusion process, especially in view of the current very short welding time of 0.1-0.5 s and relatively low welding energy levels.…”

“…Several studies showed that the addition of Zn interlayer can improve the strength of Al-to-steel joints. 20,26 The use of Zn-coated steel would also avoid the direct contact of Al to steel. This study thus involves the joining of Al/Mg/Alclad sheets to Zn-coated HSLA steel sheets.…”

Microstructure and mechanical properties of CP-Ti/X65 bimetallic sheets fabricated by explosive welding and hot rolling

“…3b and e it was found that the Fe diffusion layer in TA1 was located in the section of Area II near position B; this diffusion layer near position B had a width of approximately 5-10 µm, and Fe had a mass percentage of greater than 8% in the diffusion zone. Considering that Fe is a β-phase stable element, it is believed, based on the analysis, that the section of Area II near position B might be composed of the supersaturated solid solution formed from the high-temperature β-phase microstructures that were preserved until the temperature returned to room temperature [35,[57][58][59][60]. The residual morphology of the ASB can be observed in the section of Area III near position B, as shown in Fig.…”

“…Analysis shows that the stabilizing effect of Fe on the β phase allowed the high-temperature β-phase microstructures in the section of Area II near the X65 side to be preserved until the temperature returned to room temperature to form a supersaturated β-solid solution [35,57]. The section of Area II near the ASB side had a relatively low Fe content, which was not sufficiently high to allow the high-temperature β-phase microstructures to be entirely preserved until the temperature returned to room temperature, and thus, the morphologies of α+β microstructures eventually formed [35,[57][58][59][60]. In other words, the bright β-Ti was embedded in the shaded α-Ti matrix.…”