Research On Key Technology Of Cross Wedge Rolling Of Titanium Alloy Shaft Parts

The lightweight of equipment plays a vital role in the development of aerospace and automobile industries.Titanium alloy has excellent comprehensive performance and high specific strength,and is one of the best materials for achieving lightweight.However,the traditional processing methods of the shaft parts have some limitations,so the key technology research of the cross-wedge rolling near-net forming of the titanium alloy shaft parts was carried out.The advantages of cross-wedge rolling forming shaft parts are used to produce titanium alloy shaft parts,which solves the problems of difficult forming,complicated procedures and insufficient precision when processing titanium alloy shaft parts by traditional processing methods(machining,forging and casting,etc.),and the production efficiency,material utilization rate and quality are further improved.The macroscopic quality influence factors and the microstructure evolution of TC4 titanium alloy shaft wedge rolling process was systematically studied by using DEFORM-3D macro-micro numerical simulation,cross-wedge rolling experiment and metallographic experiment.(1)In macroscopic aspect: Based on the preliminary determination of the process parameters of the crossrolling process of titanium alloy wedges,numerical simulation was carried out.The influence of process parameters and billet size on the end quality of TC4 titanium alloy cross-wedge rolling shafts and the order of influencing factors were studied;Based on the orthogonal experimental design method,the influence of process parameters on necking was investigated.The optimal parameter combination was obtained,and the linear regression equation of each parameter and necking was obtained by the statistical data software SPSS;The influence of process parameters on the crosswedge rolling force energy parameters of TC4 titanium alloy was investigated,and the order of the influence of the parameters on the rolling moment were studied.(2)In microscopic aspect: The influence of process parameters on dynamic recrystallization volume fraction in the α+β phase region and grain size in the β phase region are investigated respectively through the dynamic recrystallization simulation;The data of dislocation density model was set into the microstructure module in DEFORM-3D by using the CA model,and the variation of grain size during rolling was visually studied.(3)The reliability of the simulation results of macroscopic quality and force energy parameters are verified by the cross-wedge rolling experiments;The credibility of the microscopic simulation results were verified through metallographic experiments in the α+β phase region and the β single phase region.