Alloy steel lost foam castings are the metal casting products cast by lost foam casting process. Lost Foam Casting (LFC), also called Full Mold Casting, is a kind of metal forming process with dry sand casting process. The EPC is sometimes could be short for Expendable Pattern Casting because the lost foam patterns could be used only once. After the foam patterns are finished by special machined, then the foamed plastic patterns are coated with refractory coating to form a strong shell to withstand the molten metal. The foam patterns with shells are put into the sand box, and fill it with dry sand sand around them. During pouring, the high-temperature molten metal makes the foam pattern pyrolyzed and “disappears” and occupies the exit cavity of the patterns, and finally the finished desired castings are obtained.
Lost Foam Casting vs Vacuum Casting |
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| Item | Lost Foam Casting | Vacuum Casting |
| Suitable Castings | Small and medium-sized castings with complex cavities, such as engine block, engine cover | Medium and large castings with few or no cavities, such as cast iron counterweights, cast steel axle housings |
| Patterns and Plates | Foam patterns made by moldings | Template with suction box |
| Sand Box | Bottom or five sides exhaust | Four sides exhaust or with exhaust pipe |
| Plastic Film | The top cover is sealed by plastic films | All sides of both halves of sand box are sealed by plastic films |
| Coating Materials | Water-based paint with thick coating | Alcohol-based paint with thin coating |
| Molding Sand | Coarse dry sand | Fine dry sand |
| Vibration Molding | 3 D Vibration | Vertical or Horizontal Vibration |
| Pouring | Negative Pouring | Negative Pouring |
| Sand Process | Relieve negative pressure, turn over the box to drop sand, and the sand is then reused | Relieve negative pressure, then the dry sand falls into the screen, and the sand is recycled |
