Research On Tool Wear And Cutting Force Of Laser-assisted Micro-milling Of TC4 Titanium Alloy

TC4 alloy is widely used in aerospace industry and biomedical field because of its excellent characteristics.In micro-milling of hard-to-machine materials such as TC4 alloy,the tool wear and breakage is one of the major problems.When TC4 alloy is used for the micromachining of precision parts such as high precision micro inertial devices,the tool wear will not only cause high processing costs but also make it difficult to get high surface quality.Laser assisted micro-milling(LAMM)can improve the machinability of hard-to-machine materials such as TC4 alloy,decrease tool wear,extend cutter life,reduce cutting force.Tool wear is the combined action of multiple wear mechanisms.The introduction of laser makes the wear mechanisms more complex.In this paper,tool wear and cutting force of LAMM TC4 alloy will be investigated as the research objects.Firstly,the tool wear of uncoated cemented carbide micro-cutter in the micro-milling and LAMM TC4 is analyzed,and the main wear mechanisms are determined respectively.According to the different wear me chanisms and the characteristics of micro-milling cutting,considering the change of TC4 material performance with temperature,the mathematical model of wear rate is established.Combine the wear rate models of different wear mechanisms,The mathematical model of tool wear rate of micro-milling and LAMM is obtained.Then,using the established tool wear rate mathematical model and Fortran language,the wear rate formula is written.Combining the secondary development technology of finite element simulation software Deform-3D,three-dimensional simulations of micro-milling and LAMM are performed.The results of milling force,tool wear,milling area temperature and so on are analyzed.The influence of the spindle speed,the feed per tooth and the radius of the tool edge on the above results is studied.Finally,the micro-milling and LAMM TC4 alloy experiments with the uncoated micro-milling cutter,and the LAMM TC4 alloy experiment with coated tool are carried out.The morphology,wear pattern and element spectrum of the tool before and after the experiments are measured by scanning electron microscope.The influence of spindle speed and feed per tooth on the milling force and tool wear under laser is studied and compared with the corresponding simulation resu lts.The tool wear model can correctly reflect the influence of cutting parameters on tool wear and cutting force and roughly reflect the value of cutting force.The influence of laser and tool coating on milling force and tool wear was studied.