In view of the problems such as coarse structure and low mechanical properties in EPC iron castings, the following measures are usually adopted to solve them at present:
1) Inoculating treatment, adding inoculant in the process of lost foam casting, refining the structure of cast iron alloy by inoculating treatment, improving the mechanical properties of iron parts;
2) The primary structure of the casting is refined by means of physical refining techniques such as vibration and other auxiliary physical fields;
3) By increasing the cooling rate of molding materials, the surface chilling effect of chilling sand and chilling coating on the solidification of metal solution can refine the casting structure.
The results show that vibration can refine the microstructure and improve the properties of magnesium alloy and Shao alloy. Therefore, it is expected to solve the problems such as coarse structure and low mechanical properties of the cast iron alloy in lost foam casting process.
As we all know, ferroalloy is a multi-element alloy composed of iron, carbon, Guangxi and other elements. When the carbon in the cast iron alloy exceeds the solubility in the molten iron, the excess carbon will exist in the form of graphite or carbide, so the phase diagram of the cast iron alloy has two forms, i.e. metastable (phase diagram and stable (graphite)) phase diagram. Because of the dual phase diagram of cast iron alloy, the solidification process may be transformed according to the metastable phase diagram or the stable phase diagram, which significantly increases the complexity of the solidification process of cast iron alloy. It can be concluded that the lost foam casting process of cast iron alloy will be different from that of Mg (SHAO) alloy. When vibration is applied in the lost foam casting process of ferroalloy, its solidification process must contain its own characteristics. The mechanism of vibration on solidification structure and properties of cast iron alloy is not clear. It is necessary to study the characteristics of structure and properties of cast iron alloy made by vibration lost foam casting.
