Die-casting Process Optimization Of Magnesium Alloy Cylinder Block Based On Numerical Simulation

Every walk of life is actively promoting energy conservation and emissionreduction, because of the emergence of the energy shortage problem. The effectivescheme, which can realize the energy saving and emission reduction, is thelightweight design for the automobile in the automotive manufacturing sector.Magnesium alloy has had a lot of applications and developments in the automotiveindustry, because it has a great advantage to reduce product weight, realizes theenergy conservation and reinforces the reliability of the product. Using magnesiumalloy to manufacture the engine cylinder block, not only can reduce theconsumption of fossil oil by reducing vehicle weight, but also can make theautomobile have a better performance for acceleration and deceleration.The object of study of this research is magnesium alloy engine cylinder blockwhich is composed by the magnesium alloy crankcase and aluminum alloy cylinder.We use the numerical simulation techniques to simulate the filling andsolidification process, and then analyzed the variation of cylinder’s flow field,temperature field in the die casting process to predict the generation of defects. Wealso provide the optimized the process of die-casting, and expect to improve thequality of cylinder body and guide the actual production.This paper introduces method of data transmit between geometrical model andfinite element analysis model. According to the structural characteristics of thecylinder, die-casting process and technical parameters, two different types of gatingsystem have been designed. Based on the analysis results of the simulation, weselect the more reasonable gating system. Then, the size of the gating system isimproved. In addition, through analyzing three different gate cross-sectional areas,we also select the best program.Through orthogonal experiment design scheme, three factors which affectingthe quality of die castings are studied, they are the mould preheating temperature,liquid metal pouring temperature and injection speed. The range analysis andvariance analysis method are used to analyse the results of simulation. Thereby, weobtain the order of the three factors which effect on the test indicators and the mostoptimal die-casting process parameters. In order to obtain the best preheating temperature of cylinder body, different preheating temperatures of aluminum alloycylinder block that influence the quality of casting have been analyzed.Based on the numerical simulation methods, we have determined thereasonable optimization die-casting process of the magnesium alloy cylinder block.It only has one gate of the gating system, thickness of straight-shaped runner is20mm, preheating temperature of the mold is220℃, injection speed is5.5m/s,pouring temperature of the molten metal is690℃, preheating temperature of thecylinder is360℃. It can effectively reduce the cylinder’s shrinkage and wrappedgas, and increase the quality of the die casting. We expect it can provide a referencefor the magnesium alloy cylinder block in the actual production applications.