Evolution of bonding interface between Ni and steel with various microstructures by ultrasonic welding

摘要

Ultrasonic welding (USW);;a solid-state bonding technique;;is potential in bonding dissimilar materials because of advantages such as short welding time;;less energy consumption;;and lower bonding temperature [ 1 ]. In the development of steel/steel and Ni/steel bonding interface during USW [2];;it is suggested that under the abrasion caused by oscillation with clamping force;;wear particles are formed and clustered to grow at contact points;;and are finally flattened to produce bonded area with plastic deformation. According to the above;;steel with different hardness resulted from different microstructures has an influence to bonding interface formation in a view of the difficulty of producing plastic deformation. However;;the understanding of the effect of steel microstructure on the bonding with other dissimilar metals is still insufficient. So;;the main objective of the present study is to investigate the effect of steel microstructure having different hardness on the bonding interface formation between steel and nickel (Ni) during USW. Ni was employed because it does not form any intermetallic compounds with steel.