Although lost foam casting technology has been widely used in the production of cast iron alloy, the solidification of cast iron alloy is a complex physical metallurgical process, and the characteristics and rules presented in the lost foam casting process of cast iron alloy need to be further studied, including the filling characteristics of cast iron alloy, the properties of EPC coating, the pyrolysis characteristics of pattern, as well as the extinction of cast iron alloy In the process of lost mold casting, there are some insurmountable defects, such as box collapse, carburization, sand inclusion, sand sticking, and deformation of parts. In view of the characteristics and existing problems of lost foam casting of cast iron alloy, researchers and technicians at home and abroad have carried out a lot of research work.
In the research results of lost foam casting of cast iron alloy, the research on the filling and pattern pyrolysis characteristics of cast iron alloy is the most. Mirbanheri and others studied the gas pressure calculation model of the flame pattern during the foam casting process in lost foam casting process, and verified the simulation results of the gas pressure calculation model by the experimental method, thus ensuring the reliability of the calculation model. Liu y et al. Established the hot pressing relationship in the cavity of EPC process by using computer assisted with temperature and pressure measurement technology, and calculated the size of pattern decomposition area at the interface of metal pattern by using experimental data. Liu Y et al. Based on the thermal stress relationship built on the lost foam mold, the gas generating characteristics of foam plastics during the process of lost foam casting were studied. Li F In order to calculate the position of the interface, the researchers also calculated the fluid flow and temperature distribution in the process of mold filling and solidification. At the same time, they predicted the shrinkage and other defects in the process of lost foam casting of nodular graphite iron, and used the simulation method to predict the lost foam The optimized design is carried out for the iron parts made of the ball ink. Lipinski et al. Combined the sub grid and mesh model to build the mathematical model of lost foam casting. The decomposition kinetics of the foam pattern was analyzed by Alexyevna’s law. The heat and mass transfer, the phase transition phenomenon of glass transition temperature and the influence of the decomposition products of the foam sample on the mathematical model were discussed. The mathematical model is verified. Khoda m and others analyzed the formability of alloy lost foam casting.
Researchers have done a lot of in-depth research on the filling problem in the process of lost foam casting, and built a mathematical model based on different theoretical basis, and verified the correctness of the mathematical model with the help of experimental methods. In addition, the researchers attached great importance to the defects in lost foam casting process as well as the research on the solutions. The related research work was carried out around the carbon black and wrinkle defects in cast iron alloy lost foam casting process, and corresponding solutions were proposed, such as the development of new foam materials. Chen Jie et al. Studied the porosity defects in the process of EPC of cast iron alloy, and analyzed the mechanism of the defects.
In addition to the study of the filling characteristics, pattern decomposition characteristics and defects in the process of lost foam casting, the researchers also studied the influence of lost foam casting on the microstructure and properties of cast iron alloy and the lost foam casting process of metal castings. He W H and others pointed out that using STMMA as foam material can significantly reduce carbon defects in castings. In addition, many researchers have studied the lost foam casting process of castings, and put forward the process improvement measures for specific parts, such as engine cylinder head, nodular cast iron automobile planetary gear frame casting, low carbon nodular cast iron grinding ball, etc. Some researchers in the preparation of gray cast iron, in the lost foam casting pattern insert copper wire for modification, it was found that the inserted copper alloy made gray cast iron graphite from A sheet graphite to B, D or E type graphite. Chakberlou TN et al. Compared and analyzed the fatigue properties of lost foam casting and sand cast ductile iron. The results showed that the fatigue properties of lost foam casting ductile iron were lower than that of sand cast ductile iron due to the presence of carbon black defects.
Although researchers have carried out a lot of research work in the key technology and theory of lost foam casting, and paid attention to the defects existing in lost foam casting cast iron alloy, the problems of coarse structure and low mechanical properties of lost foam casting cast iron alloy due to the slow cooling speed of dry sand compaction have not been effectively solved, so A lot of research work still needs to be done in the field of lost foam casting technology and control theory of cast iron alloy.