Forward design of temperature field in laser-assisted milling of Ti6Al4V alloy through numerical simulation

Abstract

Laser-assisted machining (LAM) is an advanced technique, which can significantly reduce cutting forces and improve machining efficiency of difficult-to-cut materials by preheating the local area. A crucial step for obtaining ideal machinability is to control the temperature field by modulating process parameters. In this paper, by quantitative characterization of the output laser beam quality, an analytical model is adopted to characterize the temperature field induced by the moving laser source. Following, a temperature-controlling strategy is proposed for adapting the moving path of the laser source to obtain a uniform temperature distribution within the cutting area. Then, based on the classical oblique cutting model, an analytical force model of LAM is developed sequentially coupled with the optimized laser moving path to predict the milling forces. The proposed forces model takes into account the effects of laser heating and material softening. Thus, the controlling strategy of the temperature field was established. Furthermore, the proposed strategy is verified by the variation of cutting forces during the face-milling of Ti6Al4V. The results show that the proposed strategy can significantly reduce the milling forces by over 10%. The developed force model can provide acceptable predicted accuracy, which reflects the impacts of temperature field distribution on cutting forces. In summary, the proposed strategy can effectively regulate the preheating temperature, providing a theoretical way for the forward design of laser-heating parameters.