Influence Of Loading Features On Deformation And Performance Of Thin-Walled Parts In Plastic Forming

The processing of the material not only obtains the geometry of the product,but also has an important influence on the serviceability of the part.But at present,in the stage of product design,development and manufacture,less consideration is given to the effect of processing and forming process on the final performance of the product,which results in the service performance and service life of the product not in line with expectations.Starting from the influence of loading modes of different plastic forming processes on the deformation and properties of thin-walled parts,the effects of stamping and incremental forming processes on the properties of thin-walled parts are studied from three aspects: overall compression resistance,local concavity resistance and corrosion resistance.In addition,a method of using magnetorheological materials as a filler in the bending process of thin-walled tubes to reduce forming defects and improve forming accuracy is proposed,and verification is carried out by numerical simulation and physical experiments.The main conclusions are as follows:(1)The results of physical experiments and numerical simulation show that the side wall deformation of incremental forming parts with typical convex thin shells is more serious than that of stamping,and becomes the weak area of the parts.Therefore,the stamping parts show better load-bearing performance,and their overall compressive and local concave resistance are superior to incremental forming parts.(2)After plastic forming,the bearing capacity of AL6061 parts is lower than that without considering the influence of processing;since the work hardening of SUS304 is obvious,the bearing capacity of parts is higher than that without considering the influence of processing.Therefore,the influence of the forming process on the performance of the part depends on the combination of loading,deformation and the properties of the material itself.(3)After stamping and incremental forming,the corrosion resistance of SUS304 is reduced.Incremental forming due to local point pressure and gradual feeding mode,especially due to the influence of tool head feeding on the surface quality of the blank,the corrosion resistance of the deformed area of the part is more reduced;the overall deformation of stamping forming is large,and the corrosion resistance of parts in blank holder area decreases more,but the pitting corrosion resistance of forming area is higher.(4)Physical experiments and numerical simulations show that using magnetorheological ferromagnetic particles as fillers for tube bending and using their magnetorheological properties under external magnetic field can effectively control the cross-section distortion and wrinkling of thin-walled tube bending and improve the overall forming accuracy.Among them,the ellipticity of the section of the deformation zone of the tube blank is greatly reduced compared with that without filling;the ellipticity decreases further with the increase of the applied magnetic field strength B.In addition,the magnetorheological filling material also makes the stress,strain and wall thickness distribution of the bending deformation zone more uniform,and the degree of wrinkling inside the pipe wall is reduced.Compared with other types of magnetorheological materials,hard ferromagnetic particles as a filler have the advantages of easy filling,easy preparation,easy cleaning,reusability and pollution-free.