Study On Hot Deep Drawing Characteristics Of AZ31B Magnesium Alloy Sheet

With the increasingly severe global energy crisis and the rising awareness of environmental protection,lightweight design of engineering has become a prominent topic,achieving energy-saving and emission reduction.Therefore,the demand for lightweight,high-strength,and high-rigidity materials is continuously increasing in various industries.Magnesium alloy,as a lightweight high-strength material,has become one of the representatives of "21st century green engineering materials",and its application in transportation,electronic devices,and biomedical fields is gradually expanding,and its future development prospects are significant.However,due to the structural characteristics of magnesium alloy,there are many problems in the processing at room temperature,such as cracking and difficult forming,and traditional processing methods limit its manufacturing.Many researchers have concluded that the forming temperature is positively correlated with the formability of magnesium alloy.As a result,the research on the hot forming of magnesium alloy has become the focus of scholars.Based on the aforementioned background,this research focuses on the study of the hot deep drawing process of AZ31 B magnesium alloy sheet.The high-temperature rheological curve and mechanical properties of the material were obtained through uniaxial tensile tests,and the high-temperature rheological laws were analyzed.Based on the DYNAFORM platform,the deep drawing simulation analysis of cylindrical parts was carried out to explore the influence of process parameters on the forming quality of cylindrical parts.To achieve this,a set of hot deep drawing experimental system was designed.Combined with the high-temperature rheological characteristics and numerical simulation results,a physical deep drawing experiment of the cylindrical part was conducted using orthogonal experimental design.The forming quality of the cylindrical part in the physical experiment was analyzed.The certain guiding significance of AZ31 B magnesium alloy has been produced between theoretical research and practical application by this study.And the main work of this article is as follows:(1)Based on the plastic deformation theory of AZ31 B magnesium alloy,tensile tests were performed on AZ31 B magnesium alloy at different temperatures and deformation rates to obtain the flow stress-strain curves at high temperature of AZ31 B magnesium alloy.Then,the metallographic structures under different deformation conditions were analyzed and compared to preliminarily explore the evolution law of metallographic structures of AZ31 B magnesium alloy under high-temperature tensile conditions.(2)Using the curves which obtained by the previous section,and take the thermal deep drawing simulation experiment by DYNAFORM software.The forming quality is judged by the thickness change,and the influence of four process conditions including temperature,blank holding force,speed,and friction coefficient on forming quality were investigated to provide reference for subsequent experiments.(3)Based on the existing experimental conditions,a thermal deep drawing forming experimental system was designed and manufactured on the basis of an electronic universal testing machine.The forming system consists of a deep drawing mold and a heating temperature control system.The heating temperature control system uses a dedicated heating rod as the heat source for the mold and is equipped with a thermocouple in the heating system to accurately control the system temperature.(4)Referring to the analysis results of uniaxial tensile tests and numerical simulations,a physical experiment and optimization of AZ31 B magnesium alloy thermal deep drawing forming were carried out.Orthogonal experimental method was used,with forming temperature,punch velocity,and lubrication conditions as influencing factors,the observation indexes selected maximum drawing height and maximum drawing force The effects of process parameters on the deep drawing forming of cylindrical parts were comprehensively analyzed to obtain the optimized process parameter combination.Finally,the microstructure and hardness of typical deformation parts of cylindrical parts were tested and analyzed to provide reference for the deep drawing forming process of AZ31 B magnesium alloy.