Investigations of a Pulsed AC Arc Spray Process

Modern electric arc wire spray systems enable to control the melting behavior of the wire tips to improve the layer quality by arc current modulation. This poster contributes the investigation of a pulsed AC process in which electrical parameters such as pulse frequency f, pulse voltage U_P, basic current I_grd, pulse time t_P, control speed V_Dyn, and the static slope of the characteristic curve in the pulse phase n_P are varied. By analyzing the respective current and the voltage profiles, the influence of the electrical parameters on the process performance and stability as well as the process limits are shown. The melting behavior of the wire tips during the AC pulse process is observed by high-speed recording. The movement of the arc root, the particle detachment and distribution and the process parameters are compared to a conventional arc spraying process. Finally, selected samples are characterized metallographically to determine the influence of the pulse parameters on the microstructure of the layers.