MTS model based force prediction for machining of Ti-6Al-4V

The high temperature and severe plastic deformation could promote workpiece material microstructure evolution in the machining process. The material mechanical properties are functions of the material microstructure attributes. Traditional material flow stress model approximates the material mechanical behavior at a continuum level by ignoring the microstructure effects. In the current study, a microstructure based mechanical threshold stress (MTS) model is proposed for the machining process application. The MTS model takes the material grain boundary and dislocation resistance into account. Within both the analytical and FEA machining process modeling framework, the MTS model is implemented for the machining forces prediction. The validation of the MTS application into machining forces prediction are conducted by comparison with experimental results. Good agreement is found between the experiment and prediction. Additionally, slight force prediction improvement is observed by comparing with the traditional Johnson-cook flow stress model.