Characterization of bending strength and interface microstructure in Mo/Cu explosive clads

摘要

Conventional fusion welding processes cannot be employed to join dissimilar metals with significant difference in their thermo-physical properties. Typical example is cladding a Mo plate onto a Cu plate. The elemental combination has large melting-point difference,while Mo has wear resistance and Cu has high thermal conductivity. Explosive welding (EW) is one of remarkable joining techniques for such dissimilar metals. The flyer plate is accelerated by explosion and collide with the fixed plate,resulting in emitting high velocity jets at the interface. The jets remove oxide layers on surface of the both plates,leading to strong bonding with the help of high strain rate deformation due to high collision velocity. However,joining of a Mo plate onto a Cu plate is difficult due to high dynamic sonic velocity of Mo,since shock waves upon collision should exceed sonic velocity of materials for joining. The dynamic some velocity of Mo increases with increasing collision pressure. Moreover,there is a very limitedliterature on Mo/Cu explosive clads where the authors had only discussed a feasibility of obtaining a Mo/Cu EW clad. Hence,this study was aimed to find suitable EW conditions to obtain Mo/Cu EW clads;;together with characterizing their EW interface and bending strength.