Analysis Of Titanium Alloy Die Forging Process And Its Intelligent Decision

Titanium alloy is an important structural material developed in the 1950s.It has excellent comprehensive mechanical properties and is widely used in the field of aviation.Titanium alloy can play an incomparable role in reducing aircraft weight and improving overall performance.Compared with general metals,the quality of titanium alloy forgings is mainly determined by forging process.The poor microstructure of titanium alloy formed during forging deformation is difficult to be improved by heat treatment process.Therefore,it is of great practical significance to study the forging characteristics and process of titanium alloy aeronautical structure.TA15 titanium alloy is a kind of near?titanium alloy,which has high specific strength,high working temperature and excellent welding performance.It is widely used in aviation structural parts.The processing temperature window of TA15 titanium alloy is narrow,and the forming process is demanding.In order to make correct response to various process parameters,a proper flow stress constitutive model must be established.In order to study the hot deformation behavior of TA15 titanium alloy at high temperature,the axisymmetric isothermal compression test of TA15 titanium alloy was carried out with Gleeble-3800 thermal simulator in the range of deformation temperature 800?1000?and strain 0.01?10 s^-1.Based on the test data,the influence of deformation temperature and strain rate on flow stress curve is analyzed.The rheologic stress constitutive equation of TA15 titanium alloy based on Arrhenius model was established by analyzing the data of hot compression test and curve fitting,and the established constitutive equation was verified and discussed.According to the theory of deformation thermal effect,the temperature rise of TA15 Titanium Alloy under different deformation temperature,different strain rate and different strain conditions is calculated.It is found that the lower the deformation temperature is,the higher the strain rate is,the more significant the deformation thermal effect is under high temperature compression deformation,the greater the temperature rise is,and the temperature rise can exceed 60?under certain conditions.Based on the dynamic material model(DMM)theory,the strain rate sensitivity index,energy dissipation rate and plastic flow instability parameter of TA15 titanium alloy were calculated by using the hot compression test data,and the hot working diagram was established to comprehensively analyze the high temperature deformation ability of the alloy.In this paper,the material model and geometric model of a practical arm die forging are established in Deform finite element simulation software,and the forging process is simulated according to the original process.The influence of various process parameters(forging temperature,forging speed and blank size)on the main physical field in the forming process is analyzed.The existing problems are pointed out the optimization scheme is put forward,and the simulation of the optimization process is carried out,which is compared with the original process.In order to solve the existing problems in the process of die forging in the past,based on the above research,taking the process parameters of actual production and part of simulation test as the data basis,using BP neural network,a die which can make decision on the process parameters of titanium alloy typical die forging is built,and its reliability is verified.Through these researches,the intelligent production of titanium alloy die forging has been realized to some extent,which has certain guiding significance for the future titanium alloy die forging production.