Research on the deformation mechanism and failure behavior of punch bonding technology with dissimilar sheet metals

This article presents a study of the deformation mechanisms and failure behavior of punch bonding technology for dissimilar sheet metals. Using theoretical and numerical methods, the simulation of the punch bonding process is presented and the results show that to realize effective punch bonding, the sheets with higher elastic modulus and yield strength should be located at the punch side. It is also shown that when the boss height of the female die (X ₁) is too small, it is liable to induce excessive stress concentration under the punch blade, whereas when X ₁ is too large, the embedded depth of the sheets and the bonding reliability decrease significantly. Punch bonding experiments were performed and the results showed that for the configuration tested an X ₁ value of 10 mm was optimal for connection strength. The failure behavior of the punch bonding joint was joint cracking with smaller female die boss height and joint pull-off with larger female die boss height.