Three dimensional Monte Carlo simulation of grain growth during GTA welding of titanium

The work reported here represents significant advancement in the modeling of grain structure evolution in metallic systems. Utilizing computed temperature fields from a well tested heat transfer and fluid flow model, the evolution of grain structure was simulated for the first time using a three dimensional (3D) Monte Carlo model of grain growth in the heat affected zone of commercially pure titanium welds. The computed weld geometry and the simulated mean prior β grain size for different heat inputs agreed well with the corresponding experimental results when turbulence in the weld pool was considered. The grain sizes at various locations equidistant from the fusion line were different, indicating that the results of previous 2D calculations need to be reexamined. The computed grain size distribution agreed well with the corresponding experimental data. The agreement indicates significant promise for understanding grain growth in the entire heat-affected zone using a comprehensive phenomenological model.