| With the energy and environmental issues becoming increasingly prominent and the improvement of the requirements of low-emission, high efficiency, lightweight in the automotive industry, the development and application of high-performance light-weight materials draw growing concern of the automotive industry. Currently, the light alloy of aluminum alloy and magnesium alloy are widely used in the industrial sector, and the unique advantage of the magnesium alloy makes it become a focus of materials research, and so that its research is ascendant. The substance of pressure casting (the casting) is a method making the liquid or semi-liquid metal fill in the die-casting-type cavity and solidificate in a relative high speed under high pressure. High-pressure and high-speed in the process of the filling are two major characteristics of die-casting. Filling time is very short, generally in the range of 0.01 ~ 0.2s. The high-pressure die-casting as a advanced casting process has many advantages. Especially because of its high-voltage and high-speed filling, it can produce the thin-walled castings with clear outline and the complex structure that is very difficult to traditional casting methods to complete. At present, as the increasing application of magnesium alloy castings, the performance of the filling of magnesium alloy die-casting is being asked to meet the higher demand. The scope of application of magnesium alloy high-pressure die-casting also needs to expand. Today's academic knows few about the laws of die-casting of magnesium alloy, the relationship between filling performance and die-casting process parameters and the critical thickness of the filling, so that depth studies should be carried out. In view of the die-casting theory of magnesium alloy is not yet enough mature, we should vigorously study the computer simulation studies of magnesium alloy die-casting filling and solidification process to guide the formulation of die-casting process, die-casting die designing, die-casting quality control, improving the magnesium alloy die castings passing rates and the service life of die-casting mold. Die-casting process computer simulation can help engineers and technicians to carry out computer simulation. Through simulation, we can effectively forecast the size, location and occurring time of possible shrinkage cavity before the actual production in order to continuously improve process, effectively control of filling and solidification process to get the purpose of reducing trial cycle , lowering production costs and ensuring casting quality and providing protection for improving product yield and shortening the development cycle. Application of numerical simulation technology of casting process can transform and upgrade traditional casting techniques, so the subject has a relative important guiding significance for the actual industrial production. This in-depth research about the high-pressure die-casting process of magnesium alloy automotive engine covers of TAL aims at getting the relevant process parameters accessing to production and application and expanding the application of Procast numerical simulation in the production practice.This study reviews the origin and development of ProCAST numerical simulation software on, and introduces the basic principle of the method of numerical simulation, expounds the flow field of the casting, the mathematical and physical model of temperature field and stress field.Three-dimensional modeling software used in this study is Pro / E. We can achieve the three-dimensional maps of the main parts, the gate part and the exhaust parts based on the use of anti-mold casting method, and through accurate match, merger into three-dimensional map, clean up joints, remove of convex sets on the top material point, and finally simplify the model. Through a study, we found that the file format *. X_T of UG's output Parasolid could be better compatible than file format IGES of the Pro / E's output ProCAST: the IGES format outputs by Pro / E would be a serious phenomenon of the left side after reading by the ProCAST MeshCAST module, after division of the grid a large number of missing face, overlapping face, hanging points and negative Jacobian units, can not manually patch grid. Using UG as an intermediary format conversion software, and optimizing the model, outputing Pro / E of the IGES file into UG and then saveing as *. X_T format, reading by the module and into MeshCAST grid surface and finding less face-breaking, you canrepair artificial mesh patch. This is because the output of UG is casting three-dimensional map entities, Parasolid file format of *. X_T graphics attributes can be converted to be the most complete map of the basic non-throwing side.Using MeshCAST of the module division ProCAST face, body grid, divided into the grid surface was found with a smaller grid such as the unit of length 2.0mm, in delineating the course of the sudden closure of the MeshCAST, this may be due to the grid is too small. Therefore we use 3.0mm as a division of the grid unit length of the grid. PreCAST module is used to parameter settings, the test methods are used to simulate the virtual tools have the advantage of eliminating the division of the mold grid. DataCAST and ProCAST solver module, ViewCAST and Status module view the status of filling and solidification defects in the distribution.High pouring and mold temperature will lead to be extended each cycle the length of time, resulting in a decline in productivity. Low pouring temperature and mold temperature may have insufficient water, cold traps and other defects when the liquid metal as a result of liquidity problems.The lower casting speed, more likely for lack of water defects appearing, and it will affect the filling effection; The higher casting speed of the metal is, the more serious the impact of mold is, and it is possible instability in the turbulent flow field, etc.,it may roll the formation of pores into the air, is bad to the filling. After numerous comparative simulation and analysis, the high-pressure die-casting of magnesium alloy automotive engine-cover process parameters is: pouring temperature 680℃, mold temperature 200℃, filling pressure 70MPa, casting speed of 4.8m / s, Die Casting Mold Filling is smoothy under these conditions, cooling rate is uniform and rapid, and the defects are fewer. The parameters are given through the experimental, and it is direction to practical significance...
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