Research On The Law Of AZ31 Magnesium Alloy Cups Deep Drawing

As a green structural material in the 21 st century,magnesium alloy has broad prospects for development in many fields of lightweight due to its excellent comprehensive performance.The sheet deep drawing process is a basic process widely used in the manufacturing industry.Improving the deep drawing technology of magnesium alloy sheets has gradually become the research focus of the industry.However,the plastic deformation ability at room temperature is very poor.Based on this background,this paper studies the deformation mechanism of AZ31 magnesium alloy rolled sheet under different process parameters,summarizes the forming law,which has certain guiding significance for actual production.With the drawing speed of 0.1mm/min,0.5mm/min,1mm/min,5mm/min and the drawing temperature of 25℃,150℃,200℃,250℃,300℃,350℃ for single-factor influence Tensile test.The deformation mechanism of the material was analyzed from the perspective of microstructure and mechanical properties.The forming limit diagram of the AZ31 magnesium alloy sheet at 150 °C,200 °C,250 °C,and 300 °C was obtained by the Nakajima experiment.By comparing the finite element simulation software DYNAFORM with the experimental verification,the influence of different process parameters on the drawing deformation of cylindrical parts was explored,and the forming law was summarized.The main findings were as follows:The deformation modes of magnesium alloy at 200℃ and below are twinning and basal surface slip.Above 200℃,the non-basal surface slip and dynamic recrystallization become the main modes of plastic deformation,and the dynamic recrystallization behavior continues to occur when the temperature continues to rise.The increase of temperature and the decrease of drawing speed has significant enhancement ability to the plasticity of magnesium alloy sheet,but the combination of two factors is not a superimposed effect.Under too high temperature and too low speed,the sheet yield strength and tensile strength are greatly reduced,the strain hardening ability of the material is weakened,the deformation resistance is reduced,and plastic instability is prone to occur.The forming limit diagram of magnesium alloy shows an upward trend with the increase of temperature,that is,the material can withstand a greater degree of deformation without cracking.The simulation and experimental results of the deep drawing of cylindrical parts show that high temperature and low speed are conducive to the progress of deep drawing,but the combination of too high temperature and too low temperature reduces the strength of the material and greatly reduces the deformation resistance.Cracks occur at locations with severe deformation;the differential temperature drawing method can significantly improve this phenomenon,and under the premise of no chilling phenomenon,the greater the temperature difference,the better the forming effect.Finally,the accuracy of simulation and experiment is verified by the grid strain measurement system,which proves that the summarized deformation law has great credibility.