In lost-foam casting process a pattern of the desired cast-part is made from expanded materials (foam) , then the pattern is dipped into a ceamic coating and after drying, it is put in molding sand. After pouring the melt, the foam is lost and vaporized and the cast-part is formed . Lost foam process has several advantages over other casting methods :
1- Environmentally friendly, pollution reducing process.
2- Better quality in acquiring necessary smoother surface quality.
3- Cost reduction in cast-part machining.
4- Flexibility in designing complex components.
5- Omission of sand cores in molds.
6- Additional possibility for weight reduction.