Growth behavior of nitride layers formed on chromium electrodeposit in plasma-nitriding

摘要

The structural and compositional analysis on nitrides formed on an electroplated hard Cr layer during plasma-nitriding was conducted, and its growth kinetics was examined as a function of the plasma-nitriding temperature and time in order to establish a computer simulation model prediction for the growth behavior of the Cr-nitride layer. The Cr-nitrides formed during the plasma-nitriding at 550-720℃ are composed of outer CrN and inner Cr_2N layers. A nitrogen diffusion model in the multi-layer, based on fixed grid Finite Difference Method was applied to simulate the growth kinetics of Cr-nitride layers. By measuring the thickness of Cr-nitride layers as a function of the plasma-nitriding temperature and time, the activation energy ( Q) and the nitrogen diffusion constant (D_0) were determined for growth of CrN and Cr_2N. The reasonable good agreement was found in the growth kinetics of Cr-nitride layers between the simulation output and the experimental result.