Papers by Author: Tao Chen

Abstract: For the problem of the non standard cutter shape cutting edge not smooth transition connection and flank face of cutting tool grinding precision difference, the influence of wheel deformation is analyzed to different grinding linear speed, and the grinding wheel deformation error compensation grinding method is studied in this work. The grinding of annular milling cutter with double-circular-arc is processed in five axis CNC tool grinder. Finally the machining precision of annular milling cutter with double-circular-arc is tested by the tool test center, the result show that the wheel grinding method based on compensation of grinding can realize smooth transition in different parts of cutting edge belt of annular milling cutter with double-circular-arc and flank grinding precision is ensured.

Abstract: This paper aim at frequent alternating load, caused by milling large covering parts with hardened steel give rise to cutting chatter, increase surface size error in mould processing. Based on theory of helix spiral surface, design circular milling cutter with damping groove, and employ simulation of finite element to verify the efficient performance of chip breaker. Effectively reduce milling vibration problem caused by the mutation of cutting force, cutting temperature, provide theoretical model to the subsequent tool structure parameters and manufacture technology research.

Abstract: In this paper, we use the finite element simulation method to create a three-dimensional thermal mechanical coupled model that simulate the distribution of residual stress under condition of hard turning GCr15. And twice consecutive cutting simulation are required, then analysised the influence rule of two consecutive machining on surface residual stress distribution. The simulation results were compared with the experimental values, the results show that the simulated values of continuous cutting was very closed to the experimental values and the simulation results showed a certain reliability, the maximum residual tensile stress value increased significantly as the cutting speed increased.

Abstract: The metal machining 3D finite element model was established on the basis of the thermal-elastic-plastic finite element theory. And the machined surface residual stress simulation in different cutting parameters was obtained through the finite element analysis. It is concluded that the residual stress distribution variation is spoon-shaped curve. When the feed increased, the slope of the curves is smaller, however the speed increased, the slope of the curves is higher and the stress tends to negative values quicker. Finally, the experiments are carried out. The result was basically consistent with the simulation.

Abstract: By combining cutting experiment with finite element method (FEM) simulation, the effect of cutting speed on cutting force, cutting temperature and workpiece surface residual stress has been studied in precision hard turning of hardened steel GCr15 with PCBN. The research results indicate that with rise of cutting speed, cutting force somewhat decreases and periodically changes because of metal softening effect, while cutting temperature increases and its maximum lies near tool tip on the interface of cutting chip and cutting edge, and residual stress largely decreases in a small area under workepiece surface and distributes clearly like a spoon. FEM simulation and experimental results are in good agreement.

Abstract: This paper proposes a new approach to modeling the cutting force, based on friction behavior on tool-chip interface in precision hard turning. The modeling touches on such researches as into experimental relationship between cutting force and cutting load on tool-chip friction interface, equivalent transformation of radius cutting edge, transformation between orthogonal cutting and 3D cutting, and calculating cutting force coefficient. The model has realized the transformation from orthogonal cutting to oblique cutting, then to 3D cutting, which can make calculation results of all parameters in orthogonal cutting model transplant into complex 3D cutting. The experiments indicate accuracy and effectiveness of the cutting force prediction model

Abstract: The large cylinder is difficult processed material, which be based on the analysis of the processing feature of large cylinder, the method is proposed on the basics of actual case resemblance, the optimal solution is educed by calculating the vocal and the whole similarity with the technical property. The preferred system can be provided for the processing of process.

Abstract: In this paper, FEM is used to simulate the three stages of catastrophic shear occurrence, expansion and shear band formation when serrated chips are formed under adiabatic shear behavior in high-speed machining of hardened steel GCr15 with PCBN tool. By comparing data of simulation and experiment on chip morphology characters, it is indicated that they are in good accordance. Hereby, the author has analyzed strain and temperature distribution in adiabatic shear band, and dynamic characters of cutting force . The research results show that adiabatic shear band begins from tool tip and extends to workpiece free surface, and it is characterized by large strain and high temperature. In addition, it results from adiabatic shear behavior that cutting force waves regularly in a numerical range.

Abstract: By cutting experiments, this paper investigates the effect of various chamfer widths and chamfer angles on cutting force, cutting temperature, and chip morphology when hardened steel GCr15(HRC60+2) is machined with PCBN tools. The research results indicate that with the enlargement of chamfer angle both cutting temperature and main cutting force increase gradually, and especially, radial force increases more significantly. In addition, it is shown that as chamfer width increases both cutting force and cutting temperature rise. The analytical results of chips derived from cutting experiments reveal that chamfer angle being 20º, chips are the thickest and less serrated. Furthermore, chip thickness diminishes gradually with the increment of chamfer width.

Abstract: In this paper, cutting experiment and FEM simulation are combined to investigate the effect of various chamfered edge geometries on cutting force and cutting temperature distribution when hardened steel GCr15(HRC60+2) is machined with PCBN tool. The research results indicate that radial force and main cutting force increase with the enlargement of chamfer angle, and especially, radial force rises more significantly, but radial force is less than main cutting force during the entire cutting process. Cutting temperature also gradually rises as chamfer angle increases, and moreover, it is maximized on the chip-tool interface in a place of 0.1-0.2mm distant from nose.