Research On Tool Failure Mechanism In Milling Titanium Alloy

When milling titanium alloy Ti6Al4 V,the failure behavior of cemented carbide tools will reduce the stability of milling process,resulting in poor machined surface quality.In this paper,the titanium alloy material Ti6Al4 V for aviation is taken as the research object.According to the characteristics of wear failure and damage failure of cemented carbide tool in milling titanium alloy,the failure mechanism of tool in milling titanium alloy is analyzed,and the tool wear model based on analytical method is established.By studying the internal crack propagation of cemented carbide tool material under impact force,the tool cutting edge damage model is established,and the failure boundary is obtained.A tool failure boundary map suitable for titanium alloy side milling process is provided to ensure that the cutting parameters selected in the safe area within the prediction time do not fail in advance.The reliability of the tool failure boundary map is verified by the side milling titanium alloy material test of cemented carbide tools.The main research contents are as follows :In this paper,the tool wear mechanism is analyzed.Based on the analytical method,the tool wear mechanism is revealed by modeling the tool stress and temperature in the milling process.The analytical models of the crater wear and flank wear are constructed,and the change rates of the crater wear curve and the flank wear width are obtained.The analytical model is verified by experiments.The experimental data are consistent with the trend of the analytical data of the model,which proves that the model has good accuracy.The experimental results can provide a theoretical basis for the study of tool failure.Based on the tool damage mechanism,the tool damage model is established,and the crack propagation law of tool materials under different cutting impacts is analyzed.The initial and critical damage values of cemented carbide materials are recalculated by interval method,and the impact fracture limit conditions of cemented carbide tool materials are established.The range of tool safety area is obtained,which provided a basis for the optimization of milling process parameters of titanium alloy.Aiming at the problem that the tool is prone to wear failure and fracture failure during milling,a tool safety failure boundary map is proposed.The cutting parameters are selected in the safe area within the prediction time to ensure that the tool does not fail.According to the machining characteristics of Ti6Al4 V,the failure boundary map mainly considers three forms of tool failure: rake wear,flank wear and cutting edge breakage.By revealing the three failure mechanisms,the failure analysis model is established and tool failure boundary map is obtained.Compared with the test results,it has good consistency.Finally,the tool failure simulation platform in titanium alloy milling process is established by establishing GUI interface.Two main factors affecting the tool failure boundary map are input,which provided reference for the field of titanium alloy cutting.