A method for determination of the effective diffusion coefficient and sputtering rate during plasma diffusion treatment

A method for determination of the effective diffusion coefficient and sputtering rate in plasma diffusion treatment of materials is presented. The method is based on a previously proposed plasma nitriding diffusion model, where the nitrided layer thickness as a Function of time is the main input data for determination of the nitrogen diffusion coefficient. The method is compared with the results of determination of diffusion coefficients in plasma nitrided austenitic stainless steels as received by the internal nitriding model, which is analogous to the internal oxidation model. it is demonstrated that the method predicts the correct temperature dependence of the nitrogen diffusion coefficient contrary to the internal nitriding model. The calculated sputtering rate is in good agreement with that estimated in the frame of Thornton's ion plating model. (C) 1998 Elsevier Science S.A.