Mr Farid Bashirzadeh, Dr. Tohid Saeid,
Volume 9, Issue 2 (8-2025)
Unlike conventional welding methods, joining titanium alloys to steels using ultrasonic welding does not result in the formation of brittle intermetallic compounds and high torsion, causing a reduction in the mechanical properties of the joint. Ultrasonic welding of the St12-CP.Ti samples was performed at constant parameters of 7 bars, 2 s and 1 kW and variable parameter of interlayer material (Cu, 70B and Zn). The investigation of samples by OM, SEM, shear-tensile and microhardness tests revealed that Zn and Cu samples had the lowest and highest bond densities, with 42.2 and 80.6 percent, respectively. The bond density and the strength of the sample with greater interlayer deformability have higher values. Due to the high plastic deformation capability of copper, the Cu sample has generated more heat and deformation at the joint interface than in the other samples. As a result, the microstructure underwent recrystallization and grain growth after enduring severe plastic deformation. Also, the highest hardness of the steel side equal to 201 HVR was for the Cu sample, followed by 70B and Zn, respectively.
