Possible ignition of particles ejected into the gap in explosive welding of titanium

Abstract

Processes that occur in the welding gap during explosive welding are analyzed. It is shown that metal particles flying out into the gap due to the jet‐formation effect can ignite in shock‐compressed air. For most metals, the energy released thereby is small and has no significant influence on weld formation. In titanium welding on large areas, surface sections located far from the place of detonation initiation, which experience a long‐term action of a hot air flow, can dissolve a large amount of oxygen and nitrogen. If particles from these sections enter the gap, it can lead to chemical reactions with formation of TiO2 and TiN by the mechanism of internal combustion. The energy released in the gap per unit area is commensurable with and even greater than the kinetic energy of the accelerated (flyer) plate. Local bulging and rupture of metal observed in practice can be explained by ignition and combustion of gas‐saturated titanium particles in the welding gap.