Investigation On Thermal-mechanical Coupling Behavior Of The Milling Process With Microtextured Ball-end Milling Cutter

In the field of metal machining,processing the micro texture into the rake face of the cutting tool plays a certain role in anti-friction wear,which has become hot topic for reducing the tool wear when machining the difficult-to-cut materials in recent years,such as titanium alloy.Most scholars study on the stress field or temperature field of milling the difficult-to-cut materials with the micro texture ball end milling cutter,and the two physical fields are interactive.Therefore,in this paper,the distribution of the force,the temperature and the thermal-mechanical coupling field of micro texture ball end milling cutter would be studied deeply combining with theoretical calculation and milling experiments.First,the laser preparation test of micro texture was carried out,the theoretical analysis and calculation of the contact area between the cutting tool and the chip was deduced in the process of milling titanium alloy with the ball end milling cutter.The processing area of the micro texture would be got,and then preparation of the micro texture would be carried out.The milling test platform and the orthogonal test would be designed by the three factors(the milling speed,the milling depth and the feed per tooth)under the condition that the milling width is a constant.At the same time,cutting force and cutting temperature changing with time would be measured in the cutting process,which provides the data base for the force density function and heating density function.Secondly,with the milling test data,the empirical formulas of milling force,the contact area between the cutting tool and the chip and the force density function would be solved.The force density function would be regarded as boundary condition of load.Equivalent stress and displacement of the micro texture ball end milling were analyzed by the simulation.The instantaneous stress and strain of micro texture ball end milling cutter were got at any time,which provides the basis for the study of thermal-mechanical coupling behavior of the micro texture ball end milling cutter.Thirdly,the heat flux function of micro texture ball end milling cutter would be solved by dimensional analysis,and based on this,the heat density function of micro texture ball end milling cutter is solved.Through the simulation of temperature field,the heating condition of milling titanium alloy with the micro texture ball end milling cutter was analyzed,which provides the basis for the study of thermal-mechanical coupling behavior of micro texture ball end milling cutter.Finally,based on finite element simulation of thermal stress of the micro texture ball end milling cutter,thermal-mechanical coupling would be simulated.Equivalent stress and displacement nephograms were got under the action of thermal stress and mechanical stress.During the time from starting to cut in to cut out,the changing laws of equivalent stress and displacement nephograms under the action of thermal-mechanical coupling field.The stress concentration and damaged area of the micro texture cutting tool would be further analyzed in the actual cutting process.In this paper,the stress concentration and breakage area of the micro texture ball end milling would be determined when machining titanium alloy,which provides a reference for the optimization of micro texture cutting tool structure,reducing tool wear and improving the surface quality of workpiece.