Research On Extrusion Defects Analysis And Simulation Optimization Of Forming AZ80+RE Magnesium Alloy Wheels

With the advancement of technology and the needs of people’s life, the global automotiveindustry is developing rapidly, energy and environmental problems are resulted increasinglysever. For this, improving fuel efficiency and environmental protection is imminent.Magnesium alloy is the best material that equipped with lightweight automobile; applicationson the car not only can improve the comfort and safety, but also can achieve energyconservation. Billets for the original casting defects can be eliminated by extrusion, themechanical properties of the material are improved by this. So, in this paper, AZ80+REmagnesium were extruded for the automobile wheels.Firstly，the forming process of the hub were analyzed according to the three-dimensionalshape of the molding. The views of extrusion and the technology program were formulatedbase on the parts diagram. The mass and volume of the rough and the promise of majordeformation processes were calculated.Also, the range of the extrusion temperature, theextrusion speed, the suitable extrusion ratio and the lubrication were determined on the theory.Secondly, DEFORM was used to simulate the process of forming, the main hub of metalflowing, the law of the stress, the law of the strain, and the load curves were analyzed. Thefeasibility of the hub of the extrusion process was verified, the optional of presses in theanti-extrusion, the bottom forming and flanging process were formulated.Then, the hub forming extrusion parameters and the test conditions were determinedaccording to the research group experience, the wheels were preliminary trialed, and themicrostructure were analyzed, the results showed that: Various defects and problems wereappeared in the wheel forming process; The internal organization and surface tissue were different; The grains were refined by the rare earth element Ce; The grains of hub werebecome tiny and had a streamline distribution after extrusion uniform.Finally, the causes of extrusion defects and the process parameters optimization wereanalyzed by numerical simulation on the basis of the experiment. The extrusion temperature,the extrusion speed, the mold temperature, the friction conditions, the mandrel diameter, theoutlet diameter and the thickness of the bottom were discussed for the forming process, thenput forward the optimization scheme. This laid a foundation for further studies and provided atheoretical guidance for the forming defects of wheels.