In the process of lost foam casting, high temperature molten metal can quickly decompose foam pattern after contacting with foam. There are more complex physical and chemical reactions between them, and the gas produced by decomposition will be discharged into sand mold through coating. Moreover, the reaction of metal liquid with foam pattern will reduce the temperature of molten metal and lead to the decrease of metal liquid flow, which will have a certain effect on the smooth filling of the casting. Moreover, the heat exchange between molten metal and foam pattern and sand mold also affects the flow of molten metal.
| Density kg / m3 | Thermal conductivity w / m · K | Specific heat kJ / kg · K | Latent heat kJ / kg | Liquidus temperature ℃ | Solidus temperature ℃ |
| 25 | 0.15 | 3.7 | 100 | 350 | 330 |
So lost foam casting becomes more important when choosing sand and foam patterns. The thermophysical parameters of sand mold and foam pattern selected in the original process are shown in Table 1 and 2.
| Density kg / m3 | Thermal conductivity w / m · K | Specific heat kJ / kg · K | Air permeability cm2 |
| 1520 | 0.53 | 1.22 | 0.0000007 |