Influencing factors of mold filling and solidification in lost foam casting

The mold filling ability of liquid metal in lost foam casting is the ability of liquid metal to fill the mold cavity and obtain castings with accurate size and clear outline. It is affected by the thermophysical properties of liquid metal, pouring conditions, mold properties and the structure of lost foam castings.

The essential difference between traditional casting and casting is that foam mold is filled in the cavity of lost foam casting. The filling process of molten metal is actually the replacement process of metal liquid and foam pattern.

The foam pattern at the filling front of lost foam casting will undergo gasification and decomposition under the action of high temperature molten metal. This process will reduce the temperature of the molten metal at the front of the mold filling, and the gasifying product will form an air gap layer between the metal liquid and the non pyrolysis foam shape. With the progress of mold filling, the pressure in the air gap layer increases gradually, which will hinder the filling of liquid metal, slow down the filling speed and increase the heat loss along the filling process. These characteristics have a great influence on the filling ability of liquid metal in lost foam casting.

In production practice, the optimization of process parameters and the improvement of casting quality depend on the analysis and understanding of process factors, especially in the numerical simulation of lost foam casting, the selection of various simulation parameters must be reasonable and appropriate. Therefore, the effects of various process parameters on mold filling and solidification of lost foam casting must be analyzed first.