Investigation of Collision Welding by High-Speed Imaging

Abstract

Collision welding bases on the oblique collision of two joining partners at high relative velocities. Until today, the mechanisms of collision welding are not yet fully understood due to the variety of phenomena occurring during the collision. One of these phenomena is the cloud of particles whose influence on bond formation has been neglected concerning its stored thermal energy. For the investigation of this influence, a collision welding model test rig was used which allowed the precise adjustment of the process parameters. The process observation was implemented by an image intensifier camera to visualize the ongoing collision and the occurring process phenomena. In this manuscript the developed methodology and the results of high-speed process observation are presented. The findings confirmed previous research regarding the shape formation of the cloud of particles and the influence on bond formation. It was found that the temperature of the cloud of particles depends strongly on the collision angle. Furthermore, an accumulation of the cloud of particles during the collision process was recorded which might influence the steadiness of the welding process.