Modelling the nitriding in titanium alloys

The work is dedicated to experimental study and computer modelling of the process of surface hardening in titanium alloys by means of nitriding. Four titanium alloys were used, namely Ti-6Al-4V, Ti-6Al-2Sn-4Zr-2Mo, Ti-8Al-1Mo-IV and Ti-10V-2Fe-3AL The nitriding was performed at 950 and 1050degreesC for different periods of time of 1, 3 or 5 hours. The nitrided layers were studied by microscopy, X-ray diffraction and hardness/microhardness measurements. The experimental results were used to develop computer models for simulation and monitoring of the nitriding process in titanium alloys. The modelling is based on the fundamental diffusion theory. The diffusion equation is solved at different initial and boundary conditions applying both analytical and numerical solutions. Good correspondences between modeling and experimental results are observed. Program packages for use of the models are developed.