Study On Processing Properties Of Ti-6Al-4V Titanium Alloy

Titanium alloy is widely used in the aerospace,military ships and other industries because of its good mechanical properties and chemical properties,and it is also commonly used in medicine and the automotive industry.However,surface quality of titanium alloy has a large effect on fatigue life and corrosion resistance according to use to the scene situation,the titanium alloy failure phenomenon also happens frequently due to the processing quality.In addition,high plasticity,high hardness and serious work hardening of titanium alloy make its surface quality difficult to improve in the cutting process.This thesis work Ti-6A1-4V titanium alloy as the research object with the finite element analysis under different cutting parameters and experimental research,draws on the premise of meeting the requirements of surface quality parameters combination with the highest machining efficiency.Moreover,conduct WEDM experiment with Ti-6A1-4V titanium alloy,analyzes the electrical parameters which affect the surface quality of titanium alloy.The thesis,after investigation on a large quantity of domestic and international literatures about metal cutting,analyses key technology about FEA simulation of metal cutting. On this basis,make use of a two-dimensional orthogonal metal cutting model of K class carbide tool turning Ti-6A1-4V titanium alloy with the special finite element analysis software AdvantEdge.And the rule of cutting force,cutting temperature,chip shape and machining-induced residual stresses with the change of cutting parameter and cutting tool geometry parameter are analysed.In order to research the changing rules of surface quality of titanium alloy with the change of cutting parameters,turning experiments of Ti-6A1-4V titanium alloy are conducted. After the experiments,surface roughness and cutting temperature are obtained and the rule of cutting parameter and cutting tool geometry parameter are analysed,and compare the law of experiment to the law of simulation. Contemporary,conduct WEDM experiment with Ti-6A1-4V titanium alloy bar,analyzes the surface quality of the workpieceunder different electrical parameters,and compare the results to the results of turning experiments.Prediction model of surface roughness is fitted by using response surface method on the basis of surface roughness under Box-Behnken experimental conditions.With the constraint conditions of prediction model, with objective function of metal removal rate, with boundary condition of value range of three factors of cutting, carrying on optimal combination of cutting parameters under homologous constraint value by using multi-island genetic algorithm optimizing,optimal cutting factors for quality of the machined surface are obtained.