| Titanium alloy has the advantages of high strength,corrosion resistance,and oxidation resistance.It is commonly used to manufacture curved thin-walled parts of industrial types.However,the curved thin-walled parts of titanium alloy materials have poor rigidity,low processing stability,and are susceptible to milling forces during the milling process.Deformation and chattering are caused by the effect of the metal,which reduces the surface processing quality of titanium alloy thin-walled parts.The unique arc-shaped cutting edge of the ball-end milling cutter can continuously mill curved surfaces of thin-walled parts.Therefore,the process,milling parameters and processing cases of milling the titanium-alloy thin-walled parts with a ball-end milling cutter have a theory Research significance and practical application value.In this paper,the milling of Ti-6Al-4V thin-walled parts with ball-end milling cutters is taken as the research object.The milling force model of ball-end milling cutters and the elastic damping system model for milling are established.Then,the ball-end milling cutters are analyzed by finite element simulation.The process of milling Ti-6Al-4V thin-walled parts.Orthogonal milling experiments were designed to verify the theoretical and simulation models.Based on the experimental results,the milling parameters were optimized based on the genetic simulated annealing algorithm.Finally,the optimized milling parameters were used to simulate the thin-walled parts of the integrated impeller blade.The main research contents of the paper are as follows:(1)The domestic and foreign literature related to milling processing was consulted,and the main research directions of the thesis were determined by analyzing the current research status of domestic and foreign milling processing.The analysis of the milling process of Ti6Al-4V thin-walled parts by ball-end milling cutter is taken as the research content of this paper.(2)By analyzing the geometrical relationship of ball-end milling cutter milling processing,a milling force model is established,and the overall instantaneous milling force expression is derived.Then,the milling force coefficient and milling process under variable curvature of the ball-end milling cutter are studied,and the influence of milling parameters on the change of milling force is analyzed based on the simulation results of the milling force model.(3)An elastic damping system model was established based on milling dynamics,and the expression of critical cutting depth without flutter was derived.Modal experiments were performed using the frequency response function method,and the modal parameters of the ballend milling cutter and Ti-6A1-4V thin-walled parts were obtained.Based on the elastic damping system model and modal experimental results,the effects of modal parameters and milling force coefficients on the stability of milling are analyzed.(4)Through the finite element simulation of the process of milling Ti-6Al-4V thin-walled parts with ball-end milling cutter,the stress field,temperature field and milling force of Ti-6Al4V thin-walled parts during the milling process are analyzed.The process of chip formation and separation in the milling process was studied.(5)An orthogonal milling experiment was designed.The milling force measured by the milling experiment verified the correctness of the milling force model of the ball-end milling cutter and the finite element simulation model of the milling process.The milling parameters were optimized based on the genetic simulated annealing algorithm Then,the simulation of the optimized milling parameters is verified through the simulation process of the integrated impeller.In this paper,the milling force,temperature,stress field and milling parameters of a ballend milling cutter for milling thin-walled titanium alloy parts are studied.It provides a theoretical basis for improving the processing quality and processing stability of thin-walled titanium alloy parts.Guidance is provided by milling operations. |
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