Study On The Forming Process Of 5A02 Aluminum Alloy Tube By Magnetic Pulse Driving Elastic Medium

With the acceleration of the lightweight process of automobiles,aluminum alloy materials can significantly reduce the weight of automobiles and are widely used in the lightweight manufacturing of automobile parts.At room temperature,the plasticity of aluminum alloy pipe fittings is low,and it is difficult to process and form.Therefore,it is particularly critical to continuously explore new aluminum alloy pipe fitting forming processes and improve the forming performance.In this thesis,the magnetic pulse-driven elastic medium forming process of 5A02 aluminum alloy pipes is researched.The combination of magnetic pulse forming and soft mold forming methods is used to explore the forming performance of 5A02 aluminum alloy pipes under the new process.In this paper,a complete magnetic pulse-driven elastic medium forming tool for aluminum alloy pipes is designed,which is composed of forming coils,impact devices and forming molds.The 5A02 aluminum alloy pipe fittings were subjected to a magnetic pulse discharge test to study the changes in the forming properties of the pipe fittings under different discharge energy and different temperatures.Set the magnetic pulse discharge energy to 5k J,5.5k J,6k J,6.5k J and 7k J respectively,and compare the bulging profile,wall thickness distribution law,axial length change law and strain magnitude of the pipe after the test.The test results show that with the increase of the energy of the magnetic pulse discharge,the bulging profile height,wall thickness reduction rate and axial length reduction of the pipe also increase,and the maximum strain of the pipe also increases.The test temperature of the pipe fittings was set to 25?,50?,100? and 150?,and the forming performance of the pipe fittings under the same discharge energy and different test temperatures was compared.The test results show that with the increase of test temperature,the uniformity of the tube after bulging is improved,the bulging height of the tube is also increased,the maximum strain of the tube is increased,and the plastic forming ability of the tube is improved.The quasi-static test results show that as the forming temperature increases,the bulging height of the pipe is greater,and the bulging height of the pipe is the largest at 150? and the bulging effect is the best.The change of temperature has a great influence on the bulging of the pipe,and the temperature can increase the forming limit of the pipe.By comparing the results of the quasi-static bulging test and the magnetic pulse bulging test,the deformation time of the pipe under the quasi-static test is longer,and the temperature has a more obvious effect on the fluidity of the metal and the axial replenishing ability of the elastic particles.Under the magnetic pulse test,the pipe is deformed at a high rate instantaneously,and the time affected by temperature is extremely short.Therefore,the improvement of the pipe forming performance under the temperature alignment static test is more obvious.Comparing quasi-static failure pipe fittings and magnetic pulse test pipe fittings,it is obtained that the magnetic pulse test can improve the expansion rate and forming limit of the pipe fittings,and the forming performance of the pipe fittings is more excellent.The composite forming process combines the advantages of the quasi-static and magnetic pulse forming processes.First,the magnetic pulse forming process is used to preform the pipe to increase the expansion rate and forming limit of the pipe,and then the preformed pipe is quasi-statically formed.In the composite forming test,the pipe fitting can be attached to the mold,and the plastic forming ability of the pipe fitting is improved.After the pipe is attached to the mold,the bulging direction is filled to the fillet of the cavity.In the composite forming test,the strain distribution of the pipe gradually decreases from the middle area of the bulging to the two ends,and the maximum strain concentration area of the pipe is the middle area of the bulging.Comparing the composite forming process,the magnetic pulse process and the quasi-static process,the maximum bulging height of the pipe fitting under the composite forming is larger,and the plastic forming performance of the pipe fitting is better.