Simulation And Experimental Study On Electromagnetic Riveting Process Of 1mm Thick 6014 Aluminum Alloy Sheet

As an important process of electromagnetic pulse forming,electromagnetic riveting technology is widely used in aerospace and automotive fields because of its ability to form a uniform interference amount and increase the material forming limit.It has become a hot research topic in recent years.As one of the lightweight materials,aluminum alloy has the disadvantages of being softened by heat,decreased in strength,and oxidized during the forming process.With the development of automation equipment for lightweight materials such as aluminum alloys,the forming and joining processes of thin aluminum alloys have also become increasingly demanding.In view of the above background,this research used 6014 aluminum alloy rivets to rivet 1 mm thick aluminum alloy plates of the same material.The dynamic numerical simulation of the electromagnetic field and deformation field during the forming process is carried out.The electromagnetic riveting forming process test and the related performance research of the formed parts provide test basis and guidance for high-speed processing of light alloy materials such as aluminum alloys.Firstly,design and process the electromagnetic riveting tooling.It mainly includes the design of coils and riveted forming parts,such as drive plates,punches,hoe upper and lower molds and springs.Secondly,the dynamic simulation of electromagnetic field and deformation field during electromagnetic riveting of 1 mm thick aluminum alloy sheet.The current was calculated by Maxwell and used as a stimulus to perform a finite element simulation of the discharge current,the induction current on the driver board,the magnetic induction intensity,and the magnitude and distribution of the electromagnetic force on the driver board during the forming process.The electromagnetic field simulation results are imported into Workbench,and then the deformation and stress fields are simulated,and the deformation and stress fields of the electromagnetic riveted joint when the forming process.The outcomes demonstrate that the discharge current is proportional to the voltage and the decay period is 0.7 ms;The maximum position of the electromagnetic force on the driving board is concentrated at the radius of 1/2 ? 3/4;The peak electromagnetic force is proportional to the square of the voltage.When the discharge voltage is 2 k V,the electromagnetic force reaches 97 k N;In the deformation field,it is found through the comparison of the interference amount that the relative interference amount is proportional to the voltage.Further,test of electromagnetic riveting forming process for sheet aluminum alloy.On the basis of numerical simulation,an electromagnetic riveting forming test was performed.The riveted forming parts under different process parameters were obtained by changing the discharge voltage,the prefabricated hole diameter,and the height of the nail rod,and the size and interference of the hoe were measured.The study found that with the increase of the voltage,the height of the steamed bread decreased and the diameter gradually increased.When the discharge voltage was 2 k V,the size of the steamed bread did not change significantly.The relative interference of riveted joints increases with increasing voltage.The size of the prefabricated aperture of the plate has a small effect on the size of the steamed bread,and the influence on the relative interference amount is first increased and then decreased,and the maximum relative interference amount is 3.2%;The larger the nail rod height,the larger the hoe diameter;A comparative study of the size of the hoe and the relative interference amount was obtained through experiments and simulations.The average relative error was less than 10%,which proved that the simulations and experiments were in good agreement.Finally,study on the properties of aluminum alloy electromagnetic riveted parts.Through the analysis and research on the tensile,fatigue,hardness and microstructure of the electromagnetic riveted formed part,the outcomes show that the electromagnetic riveting of aluminum alloy is performed under the process parameters of a discharge voltage of 2 k V,a prefabricated hole size of the plate of 6.3 mm,and a nail rod height of 14 mm.The mechanical properties of the joint are the best,and the shear strength at this time is 101 MPa.