Thermal field distribution in fly-cutting of KDP crystal and its influence on chip morphology

This paper researches the thermal field distribution of a Potassium Dihydrogen Phosphate (KDP) crystal in fly-cutting process, and explores the influence of cutting temperature on the fly-cutting process of KDP crystal. Firstly, the thermal-mechanical coupled Finite Element Method (FEM) was conducted to simulate the fly-cutting process of KDP crystal and to obtain the temperature fields under different cutting depths. Then, a fly-cutting machine and a nanoindentation instrument were used to cut the KDP crystal at different speeds. It was found that the microscopic morphologies of the chip formed under different cutting speeds are greatly different, and this may result from the different temperature rises at different cutting speeds. Finally, the chip formed under lower cutting speed was heated at different temperatures and the morphology of the heated chip was observed. The simulation results demonstrate that the temperature in the cutting zone rises to as much as 110℃ when the cutting depth increases to 200 nm. Moreover, the experiment results indicate that the chip morphology will change at 100℃. It concludes by simulation and experiments that the maximum temperature exceeds 100℃ in fly-cutting of KDP crystal. So, it suggests that the effect of cutting temperature on the mechanical property and removal process in fly-cutting of KDP crystal should be considered.