Because there is no solid phase in the initial state of the mold cavity during the micro model calculation, and the “foam” material must be set as solid (empty = no) during the mold filling of lost foam casting, when the lost foam casting model is used for the calculation of iron castings, the one-time coupling of thermal + flow + micro can not be realized as in sand casting to calculate the results of mold filling and solidification process.
Generally, coupling thermal + flow is used to calculate the filling process, and then the temperature field near the end of filling is extracted as the initial temperature field of solidification, and then coupled thermal + micro for solidification calculation. However, it should be noted that a small amount of solid phase may be generated in the filling process, and the temperature field of pure liquid phase should be properly selected for calculation according to the actual situation.
The mold filling time of lost foam casting is generally very short. When the mold filling time of lost foam casting is short, the influence of mold filling on the initial temperature field of solidification can also be ignored. The pouring temperature is used as the initial temperature field and directly coupled with thermal + micro to estimate the solidification process.