Study on the micro-interface behavior of 2024Al light alloy bonded by ultrasonic assisted solid phase diffusion welding with Ag interlayer under atmosphere

This paper introduces a new welding process. Based on the traditional solid phase diffusion welding, the ultrasonic energy field is introduced, and the acoustic plastic effect caused by ultrasonic vibration propagating in the solid phase medium is used to promote the plastic deformation of the base metal, so as to form an effective joining. Combined with the model analysis, the theory proves that the introduction of ultrasonic energy field can reduce the welding pressure and shorten the welding time. The plastic deformation was confirmed by the observation of dislocation and twinning in the weld seam with Ag as intermediate layer in atmospheric environment. The maximum shear strength of the welded joint is about 84.33 MPa. It was also found that the oxide Ag2O can help compounds with different crystal structures form bonds.