Surface Modification of Stainless Steel Using an Atmospheric Pressure Plasma Arc Driven by an External Transverse- Alternating Magnetic Field

Abstract

An experimental cleaning system for surface modification was developed. It consisted of a plasma torch with a DC power supply to generate an atmospheric pressure plasma arc, two field coils with an AC power supply to generate an external transverse-alternating magnetic field, a moving system for the plasma arc cleaning stainless steel samples. The external transverse-alternating magnetic field was applied to the atmospheric pressure plasma arc to widen its cross section and uniform its energy density distribution. Effects of process parameters, such as arc currents, gas flow rates, distances from the torch nozzle to the substrate, scanning velocities, and magnetic flux densities on the cleaning quality were investigated. The experimental results demonstrate that it is feasible to improve cleaning quality of the atmospheric pressure plasma arc with the external transverse-alternating magnetic field, which can expand the cleaning area and uniform the energy density distribution upon the substrates. As well as, the experimental results show that the cleaning region and cleaning quality of plasma arc are significantly influenced by the process parameters.