Experimental Study On Electromagnetic Forming Of V-Shaped Convex Angle Of 6014 Aluminum Alloy Sheet

In this paper,an electromagnetic forming technology of V-shaped convex angle of 6014 aluminum alloy is studied.Three test schemes,flat magnet collector,flat rectangular coil and flexible medium,are used to change the distribution of magnetic field force produced by coil,so that the appropriate force field can be obtained at the deformed part of billet,and then the V-shaped convex angle shape can be formed.By comparing the forming height of V-shaped convex angle under three test schemes,it is concluded that the test scheme using elastic medium as soft die to drive blank forming can make the blank form larger V-shaped convex angle.The theoretical deduction of the current in the equivalent discharge circuit and the electromagnetic force on the workpiece is carried out.The functional relationship of the current in the equivalent discharge circuit with time is obtained.Based on the current variation,the functional relationship of the electromagnetic force on the workpiece with time is deduced.The distribution of the electromagnetic force on the workpiece at different time is simulated by using Maxwell software,and the circular flat coil is obtained.The maximum electromagnetic force can be provided at the radius of 1/2 from the center,while the electromagnetic force near and far from the center decreases gradually.By comparing the forming height of V-shaped convex angle under different technological parameters such as discharge voltage,elastic modulus of elastic medium,vacuum degree of cavity and shape and size of elastic medium,it is concluded that the larger the discharge voltage,the smaller the elastic modulus of elastic medium and the higher the vacuum degree of cavity,the higher the height of convex angle that can be formed.The experimental results are qualitatively analyzed by electromagnetic theory.Analysis.By observing the microstructures of each section before and after deformation of aluminium alloy billet,it is concluded that the grains of aluminium sheet processed by electromagnetic forming process are evenly elongated along the tensile direction without fracture.The plasticity and ductility of aluminium alloy can be improved under high-speed deformation conditions are explained from the angle of adiabatic temperature rise.