Investment casting, which is more commonly used in precision casting, also known as Lost wax casting: The use of suitable investment materials (such as paraffin wax) to make the melt mold, repeated on the melting refractory coating and spray refractory sand process, hardened shell and drying; dissolve the internal melting mold, obtain the cavity, bake the shell to obtain sufficient strength, and burn away the remaining mold material, , the metal materials required for pouring, solidification cooling, sand cleaning after shelling, so as to obtain high-precision finished products. According to the product needs or heat treatment and cold processing and surface treatment. For example, sand casting, a large number of production plants should create conditions to adopt advanced technology modeling, core-making methods. Old-fashioned shock-type or shock-pressure molding machine production line productivity is not high enough, workers labor intensity, noise, not suitable for a large number of production requirements, should be gradually reformed. For small castings, can use the horizontal parting or vertical parting of the box high-pressure molding machine production line, the real shape of the production efficiency and high, the area is also small; for the medium can choose a variety of box high-pressure molding machine production line, air-line molding lines to adapt to the rapid, high-precision molding production line requirements, core method can be selected
High-efficiency core-making methods such as shell cores. Large castings of medium batch sizes can be considered using resin self-hardening sand molding and core making. Single-piece small batch production of heavy castings, manual modeling is still an important method, manual modeling can adapt to a variety of complex requirements more flexible, do not require a lot of process equipment. Can be used water glass sand, vrh water glass sand type, organic ester water glass self-hard sand type, clay dry type, resin self-hard sand type and cement sand type, etc. for a single-piece production of heavy castings, the use of ground pit modelling method is low cost, fast production.
Serial or long-term production of stereotypes products using multi-box modeling, Split box modeling method is more appropriate, although the mold, sand box, etc. began to invest high, but can save modelling hours, improve product quality to be compensated.
Low-pressure casting, die-casting, centrifugal casting and other casting methods, because the equipment and mold prices are expensive, so only suitable for mass production.
1. The conditional method should be suitable for For example, the production of large machine tool bed, such as casting, the general use of core modeling method, do not make appearance and sand box, in the pit core, while the other factory uses sand box modelling method, make appearance.
Different enterprise production conditions (including equipment, site, staff quality, etc.), production habits, accumulated experience are different, should be based on these conditions to consider what is suitable for what products and do not fit (or can not) do what products.
2. Accuracy requirements and costs The precision of castings obtained by various casting methods is different, and the initial investment and productivity are also inconsistent, and the final economic benefits vary. Therefore, to achieve more, faster, better, provincial, should take into account all aspects.
A preliminary cost estimate should be made for the chosen casting method to determine the casting method which is of high economic benefit and can guarantee the casting requirements.
Although China's foundry industry development in a relatively difficult period, but, from a long-term perspective, China's precision casting industry development or there is a certain hope that the market demand has slowly begun to pick up, and coupled 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 radically improve the foundry technology must do the following four points: first, the development of simulation technology, improve the accuracy of prediction, strengthen process control, improve yield. The problem of regularity is not well mastered, thus affecting the yield in mass production. Second, the combination of research and production. Besides the enhancement of innovation consciousness and the enhancement of research and development ability, enterprise's independent innovation also needs to attach importance to and strengthen the combination of "production, study and research" with precision casting enterprises as the main body. Thirdly, we should attach importance to material development. Material is the foundation of industry, there is still much work to be done at present. In the field of aerospace, the research and smelting technology of some new materials, such as alloy materials, especially superalloy, are still to be improved, and the gap between them and abroad is larger. Four, pay attention to the upgrading of equipment technology.
Technology is mainly the problem of equipment, many key equipment, such as some directional solidification equipment mainly rely on imports, so the development of precision casting equipment is still the focus.