Numerical Simulation Of AZ91D Motorcycle Engine Shell During Liquid Die Casting Filling Process

Magnesium alloys are structural metallic materials which have many good performances, such as low density,high specific strength and high specific rigidity,excellent electrical conductivity and thermal conductivity,good in absorption of vibration and electromagnetic shield. These characteristics enable the magnesium alloys to be used widely in the aeronautical and space industry,automobile industry, electronic and communication devices and so on. Magnesium alloy structure forming can not only adopt casting but also plastic working, but chiefly adopt die casting.Because of the weakness of die casting, School of Material Science and Engineering of Harbin Institute of Technology cooperate with Ka Shui Holdings Co., Limited of Hong Kong to research the technology of liquid combination process of die casting and forging. That is a new forming method under condition of the same forming process which can continuously complete two functions: liquid die casting and liquid combination process of die casting and forging and precisely control shape and service performances of parts at the same time. The cooperative item will decide to develop and research a special purpose machine and mould. The special purpose machine can complete not only forging technology but also die casting technology. When the special purpose machine installation have been completed, we will take the AZ91D magnesium alloy shell of motorcycle engine as an example to test processing properties of the special machine and optimum its performance.In this paper, we simulate die casting filling process of AZ91D magnesium alloy shell part with FLOW3D software to predict the location of surface defects so that the runner and gating system can be optimized. And then in order to find the best die casting processing parameters, we simulate die casting filling process with the help of orthogonal experiment. The simulation results of temperature field,velocity field,pressure field and surface defect concentration show the optimized processing parameter is pouring temperature 635℃,injection speed 3m/s,mold initial temperature 210℃.Under the condition of orthogonal experiment process parameters, we analyze mechanical properties of all parts...