| As the lightest structural material presently in the practical applications, magnesium alloys have high potential in 3C,automobile,products of national defense industry and aerospace,people's everyday life.The stamping products of magnesium alloy sheet metal have became a trend in use of magnesium alloy as its better mechanical properties and superficial qualities,but the deep drawing technology is used more wider in stamping technology.Because deep drawing technology is a extremely complicated process which includes nonlinear conditions of geometry,material,boundary conditions and mechanics and so on,study on deep drawing technology of magnesium alloy sheet metal become the key whether complicated plastic forming products can be aquired.Pointing at the current research situation and actual requirements of deep drawing technology of magnesium alloy sheet metal,this paper carried out experimental research,theoretical research,numerical simulation and further development about the key technology during warm deep drawing of magnesium alloy sheet metal.The results have stronger scientific sense and important project application value in guiding the product design process of magnesium alloy, shortening the product development cycle,decreasing material consumption and guaranteeing product quality etc.The main contents include as follows:Design and construct a set of experimental installation of warm deep drawing of magnesium alloy sheet metal,which can control deep drawing temperature and velocity automaticly and supplys consults for realizing industrialized installation of magnesium alloy sheet metal products by warm deep drawing;Through the installation,experiments of warm deep drawing of AZ31B and ME20M were carded out to acquire the best parameters of technology,which supply basis to put forward optimal technology plan of magnesium alloy sheet metal warm deep drawing.Utilizing optical microscope of metallographic,the metallographic organizations of warm deep drawing cylinder parts of magnesium alloy sheet metal were observed and analyzed.The results indicates:controlling parameters of technology reasonably during production of magnesium alloy sheet metal and sheet metal deep drawing jointly can control variation of metallographic organization to ensure the magnesium alloy sheet metal deep drawing parts own good mechanical properties because of little grain structure.Through experimental studies on hot tensile of magnesium alloy sheet metal,a mathematical model of high temperature flow stress was put forward first which includes an inconstant strain softening factor suit to magnesium alloy sheet metal warm forming;BP neural network was also used to forecast high temperature flow stress of magnesium alloy sheet metal warm forming,the forecasting results of the mathematical model of high temperature flow stress and BP neural network and experimental results were compared to verify the science and accuracy of the mathematical model put forward by this paper;And the mathematical model was joined into ABAQUS through further development by user subroutine VUMAT using FORTRAN language,it realized an aim to join new material model into ABAQUS.Design and construct a set of experimental equipment for measuring friction coefficient on line at the round comer of punch and die during magnesium alloy sheet metal warm deep drawing cooperatlely,and did the experiment under considering forming temperature,blank holding force,lubricant and so on,dynamically changing friction coefficient models about forming temperature and blank holding force at the round comer of punch and die were put forward separately;And the friction coefficient models and a modified Coulomb friction law were joined into ABAQUS through further development by user subroutine VFRIC using FORTRAN language, it realized an aim to join actual friction boundary conditions into ABAQUS.Finally,through different methods to acquire material model and friction boundary conditions,numerical simulations of magnesium alloy sheet metal warm deep drawing were made in ABAQUS,and the results were compared with experimental results.It indicates:the mathematical model of magnesium alloy sheet metal high temperature flow stress and dynamically changing friction coefficient models at the round comer of punch and die during magnesium alloy sheet metal warm deep drawing put forward by this paper have stronger scientific sense and important project application value,and the way through further development to join them into ABAQUS is totally correct;the research results of this paper have done adequate preparations for guiding actually production of magnesium alloy deep drawing and other plastic forming products,decreasing production costs in practice greatly.
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