In the research of numerical simulation of lost foam casting, Wang et al. Analyzed the mold filling process of aluminum alloy castings in the process of lost foam casting, and understood the flow and heat transfer of liquid metal in the process, and the three-dimensional shape of aluminum alloy castings is arbitrary. Finally, the research conclusion is obtained by comparing the experimental results with the actual results. It is studied by calculating the flow field, and the calculation of the flow field is obtained by solving various equations. The main equations used are energy, momentum and continuity equations. These equations are solved by FDM method. In the process of lost foam casting, we should consider that the decomposition of foam pattern will affect the flow of molten metal, and the decomposition of foam pattern is also affected by other conditions. For example, the thickness of foam sample, the thicker the thickness, the longer the decomposition time is, the greater the impact on the flow of metal liquid, and the higher the temperature of molten metal and the higher the temperature, the faster the decomposition of foam sample will be. The metal will flow faster and the metal indenter will affect it. The higher the pressure head, the faster the decomposition of the foam will be and the faster the metal will flow. Considering these factors comprehensively, the flow field of liquid metal is simulated through calculation, and finally the defects and the location of defects in castings are predicted.
Because the research on sand casting has been quite mature, and there has been a corresponding calculation model for the research on flow field in sand casting, Chen et al. Studied lost foam casting on the basis of sand casting research. They studied the flow of liquid metal in lost foam casting and assumed that the amount of liquid metal flowing out of the inner gate would affect the flow of liquid metal. Based on this assumption, they integrated the calculation model of sand casting flow field, established the model for the calculation of lost foam casting flow field, and verified the research results, The verification method is a relatively simple horizontal disk method.
Li Fengjun of Tsinghua University also studied the simulation of lost foam casting process, mainly simulating the flow field of liquid metal in lost foam casting process, using the principle that the flow front of liquid metal in lost foam casting process is similar to that of artificial neural network, and measuring the velocity of liquid metal flow front, Then the empirical formula is obtained by linear regression method, and the flow velocity of liquid metal flow front is inferred for simulation.
The above is the research on the simulation of lost foam casting by scholars at home and abroad. We can know that so far, the research on the flow of liquid metal in the process of lost foam casting is not comprehensive. There are too many unknown and uncertain factors to establish a more mature calculation model and accurately simulate it, especially for castings with complex three-dimensional shape, Therefore, the research on lost foam casting simulation remains to be verified.