Study On Forming Process Of Hollow Shaft Of Aluminum Alloy By Cross Wedge Rolling

Aluminum and its alloys have the advantages of light weight,high specific strength,impact resistance and corrosion resistance.On the premise of guaranteeing the service performance of parts,replacing steel parts with aluminium alloys can reduce the weight by more than 30%.Therefore,the use of aluminium alloy to produce shaft parts has significant advantages.However,when the cross wedge rolling process is used to produce solid axles of aluminium alloy,the defects such as looseness and cavity are very easy to occur in the center,which seriously reduces the strength of the product and even leads to the failure and scrap of the product.Therefore,using cross wedge rolling technology to produce aluminium alloy hollow shafts,on the premise of meeting the performance requirements,can not only avoid the internal defects of solid shafts such as looseness and cavity,but also reduce the use of aluminium alloy materials,save costs,and play a series of advantages of aluminium alloy,realize the lightweight of shaft parts.In this paper,the forming process of cross wedge rolling aluminium alloy hollow shaft is studied by DEFORM-3D finite element analysis and experiment.The rolling rotation condition,flattening instability condition and surface defect formation condition of cross wedge rolling aluminium alloy hollow shaft are analyzed,and the rolling parameters are determined accordingly.On this basis,the deformation temperature range of aluminium alloy is narrow,and it is sensitive to deformation temperature and deformation rate.This paper analyses the temperature field changes during the rolling process of aluminium alloy hollow shaft cross wedge rolling at different initial rolling temperatures,and studies the rolling damage at different initial rolling temperatures,which lays a foundation for determining reasonable rolling temperature and improving the rolling quality.The relative cylindricity of outer diameter and inner diameter is introduced as the quantitative evaluation index of the wall thickness uniformity in the axial direction of the rolled piece.The influence of rolling parameters on the relative cylindricity is analyzed,and the influence of rolling parameters on the variation of wall thickness is studied,so that the wall thickness can be adjusted.Then,the micro-evolution law of the hollow axle of cross wedge rolling aluminum alloy in different rolling stages is studied.The point tracking method reveals the intrinsic relationship between process parameters and microstructure evolution,and provides reference for optimizing process parameters and improving the quality of aluminium alloy hollow shafts.Finally,the rolling experiment of cross wedge rolling aluminium alloy hollow shafts is carried out toverify the feasibility of cross wedge rolling aluminium alloy hollow shafts,and the cylindricity and thickness-diameter ratio of the rolled parts are measured and calculated.The comparison of simulation results proves the accuracy of the finite element model.In this paper,the feasibility of cross wedge rolling of aluminium alloy hollow shafts is verified by the combination of finite element method and experiment,which provides a reference for cross wedge rolling of other non-ferrous metal hollow shafts.