Lost wax method of precision casting now called revestment precision casting, is a kind of less cutting or no cutting precision casting technology, is an excellent technology in precision casting industry, its application is very extensive. It is not only applicable to various types, various kinds of alloy precision casting, and produce the casting dimension accuracy and surface quality is higher than other precision casting method, and other precision casting method is difficult to cast the complex castings, high temperature resistant, not easy to processing, can be used both revestment precision casting precision casting.

    The die precision casting is based on the precision casting of ancient wax mould. As an ancient civilization, China was one of the earlier countries to use the technology. Long centuries BC, ancient Chinese working people created this lost wax precision casting technology, used for precision casting with a variety of fine decorative pattern and text tripod and household utensils and other products, such as the tomb when the spring and autumn period and the statue of plate, etc. Tomb statue of plate base for multiple mutually intertwined dragons, they end to end, staggered up and down, form the middle hollow out layers of moire pattern, these designs using ordinary precision casting process are hard to make out. And by using the lost wax method precision casting technology, can make use of the characteristics of paraffin wax no strength, easy to carve, carved with ordinary tools can and want to get the tomb of paraffin wax material arts and crafts of the plates, then additional gating system, coating, dewaxing, pouring, beautiful tomb statue of plate can be calculated out.

    Modern melt precision casting method was applied in industrial production in the 1940s. At that time, with the development of the aviation jet engine, to produce complicated shape, such as blade, impeller, nozzle, size precision and the surface is bright and clean heat resistant alloy parts. Due to heat resistant alloy materials difficult to machining, complex shape parts, so that can't or difficult to use other methods, therefore, need to find a new precision forming technology. Then draw lessons from the ancient tradition of lost wax precision casting, after improvement of materials and technology, modern revestment precision casting method on the basis of the ancient craft important development. Therefore, the development of the aviation industry promotes the applications of investment precision casting, the casting precision casting continuously improve and perfect, also for the aviation industry to further improve performance have created favorable conditions.

    In the 1950s and 1960s, we began to apply the precise casting to industrial production. Within the advanced precision casting technology with great development, one after another in the aviation, automobile, machine tools, ships, internal combustion engines, gas turbines, telecommunications equipment, weapons, medical equipment and tool widely used in manufacturing industry, also used for manufacturing arts and crafts.

    So-called revestment precision casting technology, simply be with fusible materials (such as wax material or plastic) into the meltability model (referred to as "investment pattern or model), on which the coated with several layers of tailor-made refractory coating, after drying and hardening type to form a whole shell, reoccupy steam or hot water from the melt in the shell model, and then put type shells in the sand box. Dry sand by filling in all round its modelling, finally will be cast into the furnace after high temperature roasting (such as high strength shell, can need not modelling and will release the shell directly after roasting), cast type or shell after roasting, and are casting in pouring molten metal.

       Size precision investment castings, general of CT4-6 (sand mold precision casting for CT10-13, die casting for CT5-7), and, of course, due to the complexity of revestment precision casting process, many factors, which affect the casting dimension accuracy. Such as shrinkage, deformation of investment casting mould materials, shell in the process of heating and cooling line quantity change, alloy of shrinkage and deformation of the casting during solidification, etc., so ordinary size although higher precision investment castings, but still need to improve the consistency (in medium and high temperature of the wax casting size consistency to improve a lot). When the mold is pressed, the surface finish of the mold is high. In addition, the shell consists of high temperature resistant special mixture of the binder and refractory refractory coating coated on the casting and made, direct contact with molten metal inside the cavity of high surface finish. As a result, the surface finish of the molten cast is higher than that of the normal precision casting parts, which can be as large as Ra. 1.6 -3.2 mu m.

       Revestment precision 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 a little higher requirements on the parts machining allowance, and even some castings for grinding, polishing allowance, only can be used without machining. It is shown that the method of precise casting of molten die can greatly save the machine and the working hours, and greatly reduce the metal raw materials.

      Another advantage of the precise casting method is that it can accurately cast the complex castings of various alloys, especially precision casting of high-temperature alloy castings. If the blade of a jet engine, its streamlined outer wall and cooling cavity, it is almost impossible to make a mechanical process. With investment precision casting process can not only do mass production, ensure the consistency of the castings, but also avoid the residual knife lines of stress concentration after machining.