Main application scope of numerical simulation in casting process

At present, the application of computer in simulation casting process mainly focuses on the following aspects:

(1) Simulation of mold filling and solidification process. On the basis of a lot of basic research work, the numerical simulation of casting filling process has gradually reached a practical level. Many simulation algorithms for mold filling and solidification process have been studied, such as parallel algorithm, three-dimensional finite element method, three-dimensional finite difference method, numerical method and analytical method, etc. They mainly focus on mold filling simulation of casting, and their development trend is to assist in the design of gating system.

(2) Prediction of shrinkage porosity. Numerical simulation of temperature field and prediction of shrinkage defect numerical simulation of casting solidification process is the core content of casting CAE. Its ultimate purpose is to optimize process design and realize quality prediction. It is an important content to predict shrinkage porosity based on temperature field simulation.

(3) Stress simulation of solidification process. The residual stress and residual deformation of the casting are mainly simulated. The numerical simulation of the stress field during the coexistence of liquid and solid is the core of the numerical simulation of the stress field. Many casting defects such as shrinkage porosity, shrinkage cavity and hot crack occur at this stage. Because it is very difficult to measure the mechanical properties of the liquid-solid coexistence state, the mechanical model of this stage has not been established yet, so it is still a difficult point in the simulation of the whole casting process.

(4) Microstructure simulation of solidification process. Microstructure simulation is a complex process, which is more difficult than solidification and filling process simulation. In recent years, various microstructure simulation methods have appeared one after another, and have become one of the research hotspots of material science. Although these methods can accurately simulate the solidification structure of the alloy to a certain extent, due to the complexity of the actual solidification process, these methods have made many assumptions, so there is still a certain distance from the actual solidification structure simulation of the casting.

(5) Numerical simulation in other fields with the development of automobile, aviation, aerospace, national defense and other pillar industries and basic industries, it is necessary to carry out precise forming technology of new materials (high specific strength alloys such as aluminum, zinc and magnesium). These new technologies must be based on the simulation of forming process to achieve the optimal results of high quality, short cycle and low cost. Therefore, the development of numerical simulation of precision casting is promoted. Precision casting methods mainly include: low-pressure casting, pressure casting, gravity casting, lost foam casting, squeeze casting, centrifugal casting, investment casting, electromagnetic casting and semi-solid casting.