(347-0089)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 withsignificant 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 highthermal conductivity. Explosive welding (EW) is one of remarkable joiningtechniques for such dissimilar metals. The flyer plate is accelerated by explosionand collide with the fixed plate, resulting in emitting high velocity jets at theinterface. The jets remove oxide layers on surface of the both plates, leading tostrong bonding with the help of high strain rate deformation due to high collisionvelocity. However, joining of a Mo plate onto a Cu plate is difficult due to highdynamic sonic velocity of Mo, since shock waves upon collision should exceedsonic velocity of materials for joining. The dynamic sonic velocity of Moincreases with increasing collision pressure. Moreover, there is a very limitedliterature on Mo/Cu explosive clads where the authors had only discussed afeasibility of obtaining a Mo/Cu EW clad. Hence, this study was aimed to findsuitable EW conditions to obtain Mo/Cu EW clads, together with characterizingtheir bending strength and microstructural evolution around the interface.