Research On Torsion Extrusion Process And Die Design

The working conditions of high-speed trains put forward higher requirements for the performance of train contact lines,especially in contact wire strength,conductivity and wear resistance,etc.The technology of preparing train contact line is extrusion technology,The traditional extrusion technology has limited strength because of its limited deformation capacity.It has been found that the torsion of the die greatly increases the deformation of the material and greatly improves the performance of the contact line.Therefore,it is very important to add auxiliary deformation technology to extrusion equipment.In this paper,the process of reverse extrusion forming has been studied,it mainly includes the formulation of process plan,the selection of materials,the pretreatment of materials and the determination of technological parameters,to lay the foundation for the design and test of reverse extrusion die.Then,the structure of the torsion die has been designed,the main parts of the design include extrusion rod,extrusion barrel,rotating die and spline sleeve.Analysis of the components of the structure,composition and theoretical strength conditions for the strength of the mold to provide the basis for verification.After the design of the die,it is necessary to simulate the forming process of the reverse extrusion,using Deform-3D finite element analysis software to get the torsion parameters of extrusion molding process:The load stroke curve extrusion rod,analyzed the forming process of blank;the stress and strain,temperature field,velocity field and metal flow,through which you can know the deformation degree of blank;the blank of mold parts of the reaction can be obtained in various parts of the stress distribution,strength checking parts;establish the wear model of a molding wear analysis of mold,can calculate and predict the service life of the die.Experiments has been carried out on the designed die,and the change of grain size and hardness of the blank before and after deformation is analyzed,and the feasibility of the design and the torsion extrusion process are verified.