Experimental and Numerical Analysis of the Nickel Deposition and Diffusion Using Plasma in a Confined Anode-Cathode Configuration

Abstract

This work presents a theoretical and experimental study of nickel deposition on iron samples at relatively high pressure using a pulsed DC glow discharge. The deposition process was conducted in conditions similar to that used for plasma sintering, using the confined anode-cathode configuration. The cathode was made from nickel commercially pure and the samples were made from interstitial free steel and sintered pure iron. The samples were characterized by mass weight gain, scanning electron microscopy and energy-dispersive X-ray microanalysis. The deposition process was mathematically modeled and the model was numerically solved using a conservative finite-volume method. The experiments demonstrated that the deposition occurs at a constant rate, with the mass flux changing linearly with the cathode voltage in the range of parameters considered. The results obtained from the diffusion model applied to the sample presented good agreement with the experimental values. Concerning the gas phase, the proposed model helped us to clarify some phenomenological aspects of the process. However, further studies, principally in the area of electrical discharges, are needed to permit a complete comprehension of this process.