Modelling of foam degradation in lost foam casting process

摘要

In this stud, a new model was developed to calculate gas pressure at the melt/foam interface due to foam degradation during mould filling in the lost foam casting process. Different aspects of the process, such as foam degradation, gas elimination, and permeability of the refractory coating, were incorporated into this model. A computational fluid dynamic code was developed based on the numerical technique of the solution algorithm-volume of fluid (SOLA-VOF) for the simulation and prediction of the melt flow. In order to verify the computational results of the simulation, a thin plate of grey iron at 1350 deg C was poured into a transparent foam mould. The mould filling process was recorded using a 16 mm high-speed camera. Images were analyzed frame by frame, in order to measuring foam depolymerization rate and the gap volume during mould filling. Comparison between the experimental method and the simulation results, for the lost foam casting filling sequence, has shown a good agreement.