Plasma surface interaction of nitrogen plasma on AISI 304 steel

An energetic nitrogen plasma stream of a pulsed plasma accelerator was used to study plasma matter interaction with stainless steel 304 samples. The high velocity plasma stream was allowed to interact with the samples at different plasma energy densities. The exposed samples were analysed using X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive X-ray (EDX) and Micro-hardness tests. The SEM micrograph shows the formation of fine particles, melting, cracking and evaporation of sample surface at different plasma energy densities. Tentative threshold values of these phenomena were estimated from experimental observations. The XRD result doesn't predict the formation of nitrides but confirms the occurrence of stress and relaxation in the lattice. The hardness value decreases with an increase in energy density and number of exposures. The EDX results show deposition of eroded particles and envisage possibility of creation of vacancy defects.