Prediction of grain size for blade precision forging process under thermo-mechanical coupling

Blade precision forging is a high temperature and large plastic deformation process. Interaction of deformation and heat conduction results in producing large temperature unevenness inside the billet. The unevenness has a great effect on the mechanical property and microstructure of the forged blade. However, internal quality of the blade is decided by its microstructure, it is necessary to conduct a research on the microstructure of the blade forging process. Taking a blade with a tenon as an object, its precision forging process is simulated and analyzed using a 3D coupled thermo-mechanical FEM code. And based on the prediction model of Ti-6Al-4V presented by the predecessor, a study of the evolution of grain size in the forging process is made. The distribution characteristics of grain size in typical sections are obtained under various deformation degrees. This study may provide a base for designing the blade forging process and working out its parameters.