Measurement and finite element simulation of micro-cutting temperatures of tool tip and workpiece

New measurements are proposed to test temperatures of workpiece surface and tool tip simultaneously in micro-cutting.Micro-cutting finite element model is developed to predicted temperature field.An energy density-based ductile failure method is studied further to keep simulation accuracy (<4%) in any mesh distribution condition.Predicted temperatures of workpiece surface and tool tip agree well with experimental results.

Temperature generates in micro-scale cutting process has a great effect on cutting performance due to centralized heat generation. In this study, a set of micro-cutting experiments (8 μm/r≤f≤50 μm/r) were carried out to measure temperatures in micro-cutting process with high accuracy. A fast-response thermocouple with a property of self-renewing was installed in a cylinder workpiece to measure the temperatures of workpiece and tool tip simultaneously. In each test, temperature of the workpiece surface is obtained just before the hot junction of thermocouple is machined. When the hot junction is machined, the tested maximum temperature is recognized as the temperature of tool tip. In parallel, an energy density-based ductile failure material model is developed to simulate the micro-cutting process by finite element method. In simulation, when mesh distribution is changed, the predicted forces with same energy density Gε are closer to the forces at original mesh distribution than those predicted by same energy Gf. Consequently, the energy density-based ductile failure material model can reduce mesh dependence in different mesh distribution conditions. Under new mesh distribution, Temperatures of the workpiece surface and tool tip are identified in the predicted micro-cutting temperature field. The predicted micro-cutting temperatures of workpiece surface and tool tip are very close to the experimental results. Further, the variation of temperature and its relationship with chip curling are also discussed.