Precision casting which is commonly used is the investment casting, also known as the lost wax casting: selection of suitable casting mould materials of (such as molten mould made of Paraffin); in the casting was repeated dip refractory coating and cast refractory sand process, hardening type shell and dry; the internal revestment melt away and get cavity; shell firing to obtain sufficient strength and burn the residual casting mould materials,; pouring need metal materials; solidification shell after sand cleaning to obtain high accuracy of the finished product. Heat treatment and surface treatment according to the needs of the product or heat treatment. For example, sand casting, a large number of production factories should create conditions using advanced technology design, core making method. Old shock or jolt squeeze moulding machine production line productivity is not high enough, high labor intensity of workers, large noise, does not meet the requirement of mass production should be gradually change. For small castings, can adopt horizontal type or vertical type box without high pressure molding machine production line, mould production efficiency and high, covers an area of less; for parts can be made of various box high pressure molding machine production line, air impact molding line, in order to meet the requirements of rapid and high precision molding line, core making method can choose: cold core box, hot core box, shell core of high core method.
Medium lot of large castings can be considered in the application of self hardening resin sand molding and core making.
Single piece and small batch production of heavy castings, manual modeling is an important method, manual modeling can adapt to a variety of complex requirements are flexible, does not require a lot of technology and equipment. Can be used with water glass sand, VRH water glass sand, organic ester water glass self hardening sand, clay, resin self hardening sand and cement sand; for the production of a single piece of heavy castings, the pit molding method has the advantages of low cost and fast operation. Mass production or long-term production of stereotypes products using multi box modeling, split box modeling method is more appropriate, although the mold, sand box, etc., but can be used to save time and improve the quality of products to be compensated.
Low pressure casting, die casting, centrifugal casting and other casting methods, because of the high cost of equipment and mold, so only for mass production.
Conditional method should be suitable for
The accuracy of the different casting method is different, the initial investment and the productivity are not the same, the final economic benefit also has the difference. Therefore, to do more, fast, good, province, it should take into account all aspects of. Preliminary cost estimates for the selection of the casting process, in order to determine the economic benefits of high and can ensure that the casting requirements of the casting method.
Although China's foundry industry development in a relatively difficult period, but from a long-term perspective, China's precision casting industry development or a certain hope that the market demand has gradually started to pick up, but with the development of China's foundry industry has a strong strength, I believe that China's foundry industry will achieve gratifying results.
Experts said that to fundamentally improve the level of casting technology must be done as the following four points: first, the development of simulation technology, improve the accuracy of forecasting, strengthen process control, improve the finished product rate. The regularity of the problem is not very good, so as to affect the rate of finished product in mass production. Second, the combination of industry and research. Enterprise's independent innovation in addition to the enhancement of innovation awareness and research and development capabilities, but also need to attach importance to and strengthen the precision casting enterprises as the main body of production, learning, research combined. Third, pay attention to material development. Material is the basis of industry, there are still a lot of work to do. In the aerospace field, the research of some new materials, such as alloy material, high temperature alloy, etc., are still to be improved. Fourth, pay attention to the upgrading of equipment technology. Technology is the main problem of equipment, a lot of key equipment, such as some directional solidification equipment mainly rely on imports, so the research and development of precision casting equipment is still the focus.