Model of the hardness prediction for the diffusion nitriding

• Main Authors: Horák, Vladimír., Kulish, Vladimir V., Hrubý, Vojtěch., Mrázková, Tereza.
• Other Authors: School of Mechanical and Aerospace Engineering
• Format: Conference or Workshop Item
• Language: English
• Published: 2013
• Online Access: https://hdl.handle.net/10356/85362; http://hdl.handle.net/10220/10096
• Institution: Nanyang Technological University

The plasma nitriding process produces a hard near-surface thin layer of the nitrided material. The thickness of the diffused layer, produced in the course of this process, is between 0.001 and 0.6 mm. The paper presents a diffusion model of plasma nitriding that allows one to predict the material hardness distribution within the near-surface layer as a function of time for a modified nitrogen diffusion coefficient. The temperature dependence of the diffusion coefficient are considered in the paper. Hence, the model involves the reaction rates of nitrides formation. The one-dimensional transient diffusion model is then applied to a thin nitride layer. The solution thus obtained is compared with experimental data for a decrease of hardness as a function of depth and time, until the core hardness is reached.