Mechanism of Nonequilibrium Formation of Novel Interface Structures in Explosive Welding

Novel structures are commonly observed in explosive welding products. This paper presents the nonequilibrium mechanism of the welding interface. A theoretical model was established first to deduce the motion equation of the rapid accelerated flyer plate. Numerical simulations of the welding interface were carried out with the smooth particle hydrodynamic method. Both the theoretical and numerical results were compared with experimental phenomena and showed that under the very rapid application of an impact load usually associated with high-strength plastic deformation, a significant strain rate, and temperature rise, the material volumes of the welding interface are in the viscoelastic state and prone to rotation, detrusion, and dilatation. In addition, the extreme values from the nonequilibrium development of the interface structure are a consequence of the competition between the loading and unloading stress waves during the explosive welding process.