The simulation of sand casting process by computer is the frontier field of the development of global sand casting industry, and also the only way to the modernization of China’s sand casting industry. It is an important embodiment and way of the modernization of sand casting industry, and it is the hot spot and main research topic concerned by experts and scholars in the world’s sand casting industry. The computer numerical simulation of sand casting process can shorten the product manufacturing cycle, optimize the process flow, reduce the product cost, reduce the casting defects, and ensure the product quality. Therefore, it has become one of the most popular research topics in the field of sand casting.
Through computer numerical simulation, the casting quality can be predicted, including the formation and distribution of common defects, such as porosity, shrinkage and porosity, expansion and contraction, air entrapment, sand flushing, cracks, cold shut and insufficient pouring, etc. the casting defects and phenomena can help the designer to give a temperature balanced and pressure balanced pouring system, and intuitively understand the melt temperature distribution in the mold cavity through image display, To avoid the occurrence of some defects, thus reducing the blindness of formulating sand casting process and the number of tests of process parameters. These have a guiding effect on the actual production. Through the analysis and research of process parameters, the sand casting scheme can be optimized, the casting quality can be ensured, and the production efficiency can be improved.
With the support of modern computer technology, relatively perfect mathematical model of sand casting theory and efficient experimental design scheme, computer numerical simulation technology can truly simulate the sand casting process, find problems, improve product structure or process parameters, and ensure the rationality and feasibility of product design. This has a significant impact on shortening the production cycle, predicting casting defects, and reducing the trial mold and manufacturing costs. The computer simulation of sand casting process involves many fields such as sand casting fluid mechanics, heat transfer, solidification theory, process theory, numerical analysis and computer graphics. It is one of the frontiers of material science and manufacturing. With the popularization of computer application and the continuous improvement of computer performance, computer numerical simulation will become one of the core parts of modern sand casting process design and the focus and trend of modern sand casting industry.
The important content of numerical simulation technology of sand casting process is to simulate and analyze the flow field, temperature field, temperature field, stress field and microstructure of sand casting filling process. By simulating and analyzing the flow state of the liquid metal in the gating system and the mold, the gate system design can be optimized to prevent the gas from being mixed into the liquid metal during the mold filling process to produce the liquid flow separation phenomenon, and also to prevent the base metal liquid of the casting from being oxidized by the gas; The temperature field of mold filling process can be simulated to predict the defects such as porosity, cold shut and insufficient pouring; By simulating the temperature and stress field of liquid metal and mold during solidification, defects such as shrinkage porosity, stress concentration and cracks can be found. This computer numerical simulation process is more important for the production analysis of castings with extremely uneven thickness or thin-walled castings.