Is the use of fusible materials made of meltable model of investment casting process, in some special refractory coating layer on the coating, after drying and hardening to form a whole shell, and then steam or hot water from the shell in the melt model, then put the shell into the sand box, dry sand mould filling in the round finally, the casting into the baking furnace after calcination, cast or shell after roasting, the pouring of molten metal and casting.

Casting size precision, generally up to CT4-6, of course, because the investment casting process is complex, there are many factors that affect the dimensional accuracy of castings, such as mold material, mold shrinkage deformation, shell during heating and cooling of the line changes, the shrinkage rate and the alloy in the solidification process of castings the deformation, so the size precision castings although higher, but its consistency still needs improving.

When the mold is pressed, the surface of the mold cavity is of high degree of finish, so the surface of the melt is relatively high. In addition, the shell is made of a refractory coating which is prepared by the high temperature resistant special binder and refractory coating and is made of a refractory coating which is directly contacted with the molten metal. So, the surface finish of the investment casting is higher than that of the common casting parts, generally up to Ra.1.6~3.2 mu m.

The investment casting the biggest advantage is due to the investment casting with high dimensional accuracy and surface finish, so can reduce machining work, only in parts of the parts of the high demand for a little machining allowance can, even some casting only keep grinding and polishing allowance, not mechanical processing can use. It can be seen that the use of investment casting method can save a lot of machine tools and processing time, greatly saving the metal raw materials.

Another advantage of the investment casting method is that it can cast a variety of alloys of the complex castings, in particular, can cast high temperature alloy castings. Such as jet engine blades, the streamlined profile and cooling with inner chamber, with the machining process can hardly formation. The production of the investment casting process can not only be used in batch production, but also can ensure the consistency of the casting, and avoid the stress concentration of the residual knife pattern after machining.