Modelling and Simulation of Laser Assisted Milling Process of Titanium Alloy

High power thermal source such as laser beam has been applied for softening the difficult-to-machine materials when it is combined with conventional machining processes, such as milling. Analytical model and finite element method (FEM) model for the simulation of the laser assisted milling process are presented. In the analytical model, the general solution of the temperature distributed for a moving heat source in a semi-infinite body is calculated. The impact of the initial temperature to the cutting forces are taken into account, based on Johnson-Cook material constitutive law. In the FEM model, Johnson-Cook material constitutive law and Johnson-Cook material failure criteria have been implied within the material model. Sequentially thermo-mechanical coupling FEM approach is adopted. Gauss laser beam heating process is modelled as heat flux load scanning along the workpiece material surface and the temperature field with respect to time has been simulated. Then the temperature distribution about a series of discrete time steps has been taken as the initial temperature condition to the corresponding machining process simulation steps. Finally, the laser assisted titanium alloy milling simulation results of the analytical model, the FEM model, and the published experimental results have been compared. That shows the FEM model predicting cutting zone temperature, stress, and cutting forces accurately and elaborately, while the analytical model predicting cutting forces and cutting zone temperature efficiently to a certain accurate extent.