Water glass melt casting, also known as "water glass lost wax casting", is an accurate and clean model made of an easy to melt material (such as wax or plastic) - the melt mold, which is coated with a number of refractory materials on its surface, and heated to the wax mold after drying and hardening, and then roasted at high temperature to form a whole shell with a certain thickness, then redirected. The cavity is poured into molten metal to get the same casting shape.

Compared with other casting methods and parts forming methods, investment casting has the following advantages:

(1) the precision of the casting is high and the surface roughness is low. The precision of the mold casting can reach 4~6 level, and the surface roughness can reach Ra0.4~3.2 m, which can greatly reduce the cutting allowance of the castings, and can realize the free casting.

(2) castings that can be cast in a complex shape. Investment casting can produce castings, such as impeller and hollow blade, which are complex in shape and difficult to be processed by other processing methods. Also, the casting wall thickness is small to 0.5mm, the pore size is below 1mm, the outline size is small to several millimeters, the size is up to 1000 millimeters, the weight is to 1g, and the most weight can be up to several tons. It can also cast the parts which are combined and welded by many parts, and lighten the weight of the parts.

(3) alloy material is not restricted. All kinds of alloy materials, such as carbon structural steel, stainless steel, alloy steel, cast iron, aluminum alloy and copper alloy, and casting superalloy, magnesium alloy, titanium alloy and precious metal, can be used in the mold casting production. It is especially suitable for alloy materials which are hard forged, welded and machined. Production.

(4) high flexibility in production and strong adaptability. The tooling of the molten mould casting can be made by a variety of materials and process methods, so that it is suitable for mass production and small batch production, even single piece production. Mass production is made of metal mold, and small batch production can be made of fusible alloy, etc. the sample can be developed by using rapid prototyping instead of wax mold.

Sodium silicate investment casting also has some limitations, such as cumbersome process, long production cycle, too big casting size, slow cooling of castings, etc.