Numerical Simulation And Experimental Study Of Single-point Incremental Forming Process Of Ta1 Pure Titanium Plate

Progressive forming technology is a rapid forming method.Compared with traditional forming methods,it has the advantages of simple equipment and short design verification cycle.It can be manufactured rapidly in the face of the manufacture of prototype parts,single parts or small batch parts.With the development of progressive forming technology,forming materials have developed from general materials to new light materials.Titanium,as a light and highstrength material,has excellent specific strength,thermal strength and corrosion properties.However,titanium has low elastic modulus and high yield strength,and is prone to rebound and crack in the forming process,which limits its application in chemical industry,aerospace,rail transit and other fields.In this paper,TA1 pure titanium sheet is used as forming material to study its forming properties,forming equipment,process parameters and forming quality.The main conclusions are as follows:(1)Taking the hot rolled annealed TA1 produced by Panzhihua Iron and Steel Group as the object,the microstructure and macro texture evolution under different deformation were studied,the EBSD orientation image and metallographic structure morphology under different cold rolling deformation were observed,and the volume fraction and average grain size of small angle grain boundary were calculated.The results show that when the deformation is ≤ 30%,the deformation of pure titanium is mainly twins,and the activated twins are mainly compression twins and tensile twins.When the deformation reaches 70% or more,dislocation slip becomes the only deformation mechanism.(2)The deformation behavior and forming accuracy of pure titanium plate during Vbending are studied by using high-speed camera system and three-dimensional structured light scanning technology,which provides theoretical basis and technical guidance for progressive forming.(3)Through the customized development of forming tools and forming tooling,a general NC milling machine is transformed into a special progressive forming machine tool,the experimental platform of single point progressive forming is completed,and the square cone pure titanium parts are successfully trial produced.(4)The finite element modeling and analysis of the progressive forming process of TA1 pure titanium sheet are carried out,the plastic deformation law of the progressive forming material is explored,and the effectiveness of the finite element model is verified by experimental comparison.(5)Aiming at the forming accuracy and thickness of single point incremental forming,a new evaluation method is proposed in this paper,and the reliability of the evaluation method is verified.On this basis,the influence of process parameters on the progressive forming quality of TA1 pure titanium sheet is studied.The results show that the forming angle has the strongest influence on the forming accuracy and forming thickness.Increasing the forming angle will increase the offset of the sheet,reduce the stable value of the forming area,increase the limit deformation area of the sheet thickness and reduce the deformation uniformity of the sheet thickness,which will lead to the decline of the forming accuracy and the sharp thinning of the forming thickness.The second is the diameter of forming tool,which is second only to the forming angle.