Analytical prediction of temperature in laser-assisted milling with laser preheating and machining effects

Abstract

An analytical predictive model for temperature in laser-assisted milling considering both laser preheating temperature and machining induced temperature rise is proposed. The preheating temperature at top surface is predicted first by considering the heat generation from laser and convection. The heat generation rate is described by Gaussian equation. Within the material, heat conduction is considered with isothermal boundary conditions at side and bottom surfaces. The machining temperature is considered by transferring the milling configuration to orthogonal cutting at each instance. The shearing heat source and secondary rubbing heat source are included for machining temperature prediction. The heat source is calculated from the cutting or plowing forces, and a mirror heat source method is applied to predict temperature rise through integration. The proposed model is validated through experimental measurements on silicon nitride ceramics and Ti-6Al-4V alloy. The proposed predictive model matches the experimental measurements with less than 7.1% difference at laser spot and 5.2% difference in front of the cutting zone with computation time less than 15 s. The model is valuable for providing a fast, credible, and physics-based method for the prediction of temperature in laser-assisted milling of various materials. The overall temperature distribution is accurately calculated by predicting laser preheating temperature and machining induced temperature rise.