1、 Full mold castingFull mold casting, also known as&quo; Gasification mold modeling& ldquo; Foam polystyrene plastic molding&rdquo& ldquo; Lost Foam Casting; Or&quo; Cavity free casting” Etc. The essence of this casting method is to use foam polystyrene plastic pattern instead of ordinary pattern. After molding, molten metal is poured without taking out the pattern. Under the heat of hot liquid metal, the foam plastic pattern vaporizes, burns and disappears. The metal liquid replaces the space occupied by the original foam plastic pattern. After cooling and solidification, the required castings can be obtained. The full mold casting process is shown in Figure 7-4. The fundamental difference from ordinary casting lies in the absence of cavities and parting surfaces.1. Pattern and molding sand: polystyrene foam plastic is commonly used as molding material. There are two molding methods: foaming and processing. Foaming forming is the process of heating with steam or hot air to further expand the pre foamed polystyrene beads placed in the mold, filling the mold cavity and forming. Used for batch and mass production. Processing and forming refers to the use of manual or mechanical processing to prefabricate various components, which are then bonded and assembled into shape. Used for single piece, small batch production. The surface of the mold should be coated to make the casting surface smooth or improve the fire resistance of the cavity surface. Moulding sand includes self hardening sand with cement, water glass, or resin as bonding agents, and dry silica sand without bonding agents, which are respectively used for single piece, small batch production, and batch, mass production.2. Characteristics and applications of full mold casting:(1) Features:① Full mold casting does not require mold removal and repair, with fewer processes and high production efficiency;② High precision castings with complex shapes;③ Dry sand molding without adhesive can be used, with low labor intensity.④ At present, this method still has problems such as environmental pollution during pattern gasification and easy carbon addition on the surface of cast steel parts.(2) Application: Full mold casting has a wide range of applications. ① Almost unrestricted by casting structure, size, weight, batch size, and alloy type; ② Especially suitable for the production of castings with complex shapes. This casting method is being vigorously promoted and applied.