Numerical Simulation And Experimental Study On Electromagnetic Deep Drawing Process Of Aluminum Alloy Sheet

With the rapid development of science and technology,and humans are asked to save energy and reduce environmental pollution,lightweight technology has been favored in many fields.Lightweight alloys such as aluminum and magnesium are widely used in aviation,automobiles,and electronics.The deep drawing process can be applied to the formation of large coverings such as automobile bodies and aircraft skins,but the forming performance of lightweight alloy is poor.In the traditional deep drawing process,wrinkles,cracks and other defects is produced easily.During the forming process,annealing and other multi-sequence processes are performed,which increases the forming cycle and cost.Because electromagnetic forming has the characteristics of high rate and high strain rate,it can improve the forming performance of light alloys,break through the bottleneck of traditional forming processes,and is suitable for forming light alloys that are difficult to process under quasi-static conditions.The electromagnetic drawing process of annealed AA3003 aluminum alloy was taken as a research object,the traditional and electromagnetic drawing experimental platform was built,a finite element model of the electromagnetic drawing process in the electromagnetic field and structural field modules of ANSYS was established and numerical simulation analysis was conducts,Combined with experiments to study the electromagnetic drawing process.The electromagnetic drawing process of three types of coils including flat coil,stepped coil and axial stepped coil+radial flat coil are numerically simulated,and the deformation of the sheet in the process of unidirectional and bidirectional electromagnetic deep drawing is obtained respectively.The results show that under unidirectional electromagnetic drawing,the center of the sheet exhibits a bidirectional tensile stress state,with the most severe thinning,followed by the vicinity of the corners of the die;and the sheet above the die is subjected to the electromagnetic force only,so it can only be drawn into a tapered part.In the two-way electromagnetic deep drawing,the sheet material in the flange area is subjected to the horizontal radial electromagnetic force and flows to the concave model cavity during the forming process,and the deformed material is continuously replenished,which greatly reduces the thinning degree of the sheet,the forming quality is better,and the drawing is approximate tubular pieces.Subsequently,the electromagnetic drawing process of flat coil and stepped coil was carried out,the simulation results were verified,and the final forming shape,forming height,taper,die-fitting degree,thickness thinning and defects of the sheet under different structural coils and voltage conditions were obtained.The results show that forming deep-drawn parts of the same height requires lower discharge energy under the stepped coil,and the die-fitting degree is higher,and the taper is lower.When the discharge voltage is small,the thickness of the sheet at th e center of the sheet is the most serious,when the discharge voltage is increased to a certain degree,the sheet at the corner of the die is thinned most seriously,and even produce crack defects firstly.