The essence of casting CAE technology is to complete the simulation of casting solidification process with the help of computer technology, predict the possible casting defects in the, and analyze the corresponding process parameters. Casting CAE technology can simulate both macro temperature field and microstructure. Among them, macro physical field simulation is the calculation of macro transmission phenomena, including the simulation of flow field during liquid metal filling and temperature field during solidification. The simulation and analysis of macro physical field by using mature commercial casting CAE software can effectively guide the formulation of corresponding process. Compared with macro simulation, micro simulation is mainly to predict the changes of defects, microstructure and mechanical properties during solidification. From the research content, the casting CAE technology can be divided into the simulation of temperature field, flow field, stress field, microstructure and various coupling.
At present, although the casting CAE software technology has developed rapidly and can basically guide the gradual actual production, there is still a large deviation between the results of casting CAE simulation technology and the results measured in actual production for castings with relatively complex structure and high quality requirements. The main reason is that the accuracy of input parameters and the selected boundary conditions in the numerical simulation are not consistent with the actual production, which makes the cooling conditions of the simulation distorted. In the solidification process, the cooling of castings is mainly affected by the properties of casting / die materials, the heat transfer of castings / dies and their interface with the surrounding environment. The cooling condition of the casting directly controls its solidification law and final mechanical properties. Therefore, in order to make the simulation results of complex castings more reflect the real situation, accurate and complete material thermophysical parameters, initial conditions and more accurate boundary conditions are indispensable in the simulation setting.
The inaccuracy of simulation parameters is the main reason that restricts the simulation accuracy. Among them, material properties, such as thermal conductivity, density and specific heat, are usually easy to obtain and independent of the shape of the casting. In addition, the initial conditions can also be determined according to the actual pouring situation. In contrast, the interface heat transfer coefficient (IHTC) determined by die / casting material, casting shape and process parameters is difficult to give an accurate numerical curve. The reason is that in the process of metal solidification, the interface between metal and die will change significantly, so that the interface heat transfer coefficient will not remain constant, but change with the continuous change of metal solidification process. In view of the above problems, how to accurately and effectively establish the corresponding mathematical back calculation model to obtain the interface heat transfer coefficient and study its variation law is the research focus and difficulty of casting simulation technology.