Since its inception in the 1950s, China's
precision casting industry has achieved breakthroughs in many "neck-stuck" technologies in the fields of aviation, energy, and national defense after decades of technological accumulation and innovation. For example, the largest high-temperature alloy precision casting casing casting in China developed by Guizhou Anji Precision Casting Company of AVIC fills the gap in the core components of commercial aircraft engines, and its high-temperature resistance reaches the international leading level2. In addition, Chengdu Aerospace Company has overcome the problem of single-crystal hollow blades through vacuum smelting technology, and the product qualification rate is benchmarked against European and American standards, marking that my country has gotten rid of its dependence on imports for key components of aviation engines.
In the field of energy, the successful development of the high-temperature turbine blades of the first domestically produced F-class 50MW heavy-duty gas turbine adopts a hollow cooling structure design, which enables the blades to operate stably at a high temperature of 1327℃, pushing China to become the fifth country in the world with the ability to manufacture heavy-duty gas turbines. Yuchai Group has solved the process bottleneck of high-grade complex castings and improved the core competitiveness of domestic engines through the mass production of cylinder heads made of vermicular iron RuT450.
Industry leaders such as Shenyang Foundry Research Institute have achieved breakthroughs in ultra-low temperature casting technology for titanium alloys. The vacuum suspension melting technology developed by them provides high-purity titanium alloy materials for the Long March series rocket engines, helping China's aerospace industry enter a new stage of independent control. According to statistics, China's casting output will reach 51.9 million tons in 2023, accounting for 48% of the global total, but high-end castings still rely on imports, and there is an urgent need for industrial upgrading.
In the future, precision casting will focus on intelligent and green transformation. For example, 3D printing sand mold technology has shortened the mold manufacturing cycle by 60% and promoted the integrated molding of complex castings9. At the same time, the industry needs to cope with environmental pressure, reduce energy consumption through technologies such as waste sand regeneration and waste gas treatment, and keep pace with international advanced levels (for example, Germany's casting energy consumption is only 1/2 of China's).
Precision casting is a high-precision manufacturing technique primarily used to produce metal components with complex shapes and high dimensional accuracy. This technology finds extensive applications in various fields such as aerospace, automotive manufacturing, medical devices, and electronic equipment. Through
precision casting, design requirements and performance standards that are difficult to achieve with traditional casting methods can be met.
Basic Principles of Precision Casting
Precision casting, also known as investment casting or lost-wax casting, involves creating a model using fusible materials (such as wax), then using this model to form a refractory material mold. The model is heated above its melting point to melt and drain out, leaving behind a cavity identical to the model's shape. Finally, molten metal is poured into this cavity and allowed to cool and solidify, forming the desired casting.
Characteristics of Precision Casting
High Precision: Precision casting can produce parts with extremely high dimensional accuracy, typically within ±0.05mm.
Complex Shapes: For parts with intricate designs that are challenging to manufacture through other methods, precision casting offers an effective solution.
Wide Range of Materials: Almost all casting alloys, including stainless steel, aluminum alloys, and copper alloys, can be used in precision casting.
Excellent Surface Quality: Precision castings have smooth surfaces, reducing the need for subsequent machining.
Cost-Effective: For large-scale production of complex parts, precision casting can significantly reduce per-unit costs.
Application Fields
Aerospace: Precision casting is particularly prominent in the aerospace industry, used to manufacture critical components such as engine blades and turbine disks.
Automotive Industry: In automotive manufacturing, precision casting is employed to produce various complex metal parts, such as engine blocks and transmission housings.
Medical Devices: Precision casting is widely used in the production of medical equipment, especially for components that require strict precision and cleanliness.
Electronic Equipment: In the electronics industry, precision casting is used to manufacture small, lightweight, and intricately shaped parts.
Development Trends
With technological advancements, precision casting continues to evolve and improve. For example, the application of digital design and simulation software has made design more flexible and efficient. The development of new materials has expanded the scope of precision casting applications. Additionally, growing environmental awareness has prompted the industry to seek greener production processes.
In summary, precision casting plays a crucial role in many modern industries as an advanced manufacturing technology. As technology continues to advance, it is expected that precision casting will make even greater strides in improving production efficiency, reducing costs, and expanding its range of applications.
There is no uniform rule for the determination of manganese content in precision castings. Various methods are very different. For the promulgation of national standards, they are summarized and stored here in case they are needed. To measure Mn in Precision casting, you can find relevant national standards, such as the determination of manganese content GB / T 5121.14-2008, you can find the detailed answer you need, and there are very detailed steps. As for what brand of 721 measurement standard is correct, you first refer to which national standard and see at which wavelength the actual measurement is made. If it is within 360-1000, selecting 721 can solve the problem, otherwise UV-visible spectrophotometry is required meter. If the budget is sufficient, you can choose Japan; if the budget is small, you can choose domestic. Simply put, the Mn content of the standard steel in precision castings is given and known. After processing the standard steel, you prepare a series of solutions with different concentrations c, and then measure the absorbance value A to make a standard curve; Measure the absorbance value with your prepared sample solution, and get the Mn concentration according to the curve, then you can estimate the Mn content of the sample. The formula is actually A = εbc, A is measured by a spectrophotometer, c of the standard steel is known, and an A-c curve can be made. b- thickness of liquid layer, ε-molar absorption coefficient.
1. Does precision casting have to be manufactured by precision casting? Can it be used to produce thin-walled castings? The manufacturing process of precision castings is precision casting, which is without a doubt. However, this process can also be used for the production of thin-walled castings, in which the outer casing of the mold needs to be preheated at a high temperature, and the solidification speed of the metal during the casting process is very slow. It is therefore suitable for the production of thin-walled castings. 2. Does the precision casting need heat treatment? Can stainless steel be used as casting raw material? Whether the precision casting needs heat treatment depends on the actual conditions and specific requirements of the casting. If you want to further improve the performance of the casting, you can achieve this by heat treatment. However, it is necessary to rationally select the materials and select the appropriate process to achieve good results. As a good material, stainless steel can be cast by precision casting. 3. What should I pay attention to if I produce such castings in large quantities? Classification of castings? If the production of precision castings is mass-produced, care should be taken to adopt appropriate, advanced styling and coring methods to increase work efficiency and obtain high quality products. The classification of castings is generally horizontal casting and vertical casting.
