Numerical Investigations Of Tools And Cutting Parameters In End Milling Ti6Al4V

Ti6A14V is used extensively in mechanical manufacturing field such as aerospace, petroleum and automobile for its excellent mechanical property. Ti6A14V is a kind of difficult-to-machine materials due to its characteristics of poor thermal conductivity, low elastic modulus, serious work hardening and the chemical activity. The poor machinability leads to short tool life, poor machined surface quality. Improving the efficiency of machining Ti6A14V is a problem needed to solve urgently.Milling mechanism and process of Ti6A14V is simulated and experimental studied systematically based on review of milling process of titanium alloy. Cutting force, cutting temperature and specific cutting energy are calculated from simulations. The results are used as evaluation criterion of machining performance to study the influences of cutting tool geometry parameters, cutter materials, cutter coatings and cutting parameters on tool cutting performance.A three-dimensional milling model is developed, the single factor experiments are employed to analyze the influences of helical angle、teeth number and rake angle of the TiAlN/TiN/TiAIN coated tungsten carbide flat end mill on cutting force, specific cutting energy and cutting temperature. The simulation results have shown that when coated tungsten carbide tools machine Ti6A14V, teeth number is the most significant factor to influence the cutting force and specific cutting energy, then is the rake angle, the last one is the helical angle. The effects on cutting temperature are teeth number, helical angle, and rake angle. Cutting force in Y direction has the same trend with specific cutting energy, tool gets the best performance when helical angle is45°, teeth number is3, and rake angle is10.5°.A three-dimensional milling model is developed to analyze the influences of coating thickness(0.5μm、1μm、1.5μm、2μm、2.5μm、3μm、3.5μm、4μm、4.5μm、5μm、5.5μm、6μm) and coating materials(uncoated、TiAlN(4μm、Al2O3(4μm)、 Al2O3/TiN(2μum/2μm)、TiAlN/Al2O3/TiN(2μm/1μm/1μm)) of cemented carbide flat-end mills on cutting temperature of tool, cutting force and specific cutting energy. The simulation results have shown that the cutting temperature and cutting force of coated tools is lower than that of uncoated tools. The larger coating thickness, the lower cutting temperature. The specific cutting energy of coated tool increases with coating thickness. The cutting performance of Al2O3coated tool is optimal.A single factor method is employed to analyze the influences of cutting speed, feed rate, radial cutting depth and axial cutting depth on milling process. The simulation results have shown that with the increase of cutting speed, cutting forces increase first then reduce, the critical speed is120m/min; the cutting forces and cutting temperature increase with feed rate, radial cutting depth and axial cutting depth; the change of radial cutting depth and axial cutting depth is sensitive to cutting temperature.A finite element analysis of machining-induced temperature, cutting forces and stress fields in milling of Ti6Al4V with four different tools as nature diamond, PCD, PCBN and cemented carbide-K tools are investigated. Nature diamond tool isn’t suitable to machine Ti6A14V; PCD tool can be used to finishing; cemented carbide-K can be used to machine Ti6A14V in the condition of small cutting parameters; PCBN is optimal material to machine Ti6A14V and the larger cutting parameters are allowed.