Additive manufacturing, commonly known as 3D printing, integrates computer-aided design, material processing and rapid prototyping and additive manufacturingmolding technologies based on digital model files. Through software and numerical control system, it is a manufacturing technology that creates physical objects by stacking special metallic materials, non-metallic materials and medical biomaterials layer by layer according to extrusion, sintering, melting, light curing and spraying methods. Compared with the traditional processing mode of removing - cutting and assembling raw materials, it is a "bottom-up" manufacturing method through the accumulation of materials, from nothing to something. This makes it possible to manufacture complex structural parts that were not possible with conventional manufacturing methods in the past.

Additive manufacturing enterprise technology refers to the scientific management technology service system based on the principle of discrete-stacking, where three-dimensional information data from parts can drive development directly through manufacturing parts. Based on students' different classification work principles and understanding teaching methods, additive manufacturing system technology research also has a variety of titles such as economic rapid prototyping, rapid forming, rapid manufacturing, 3D printing, etc. Its connotation is still deepening and rapid injection mouldingits extension is expanding. The meaning of "additive manufacturing" and "rapid prototyping" and "rapid manufacturing" is the same.

Equipment recoating technology. The automatic coating of additive manufacturing is a necessary process for material accumulation, and the recoating process directly determines the accuracy and quality of parts in the direction of accumulation. Controlling the thickness of the coating and its stability is the key to improving coating accuracy and reducing surface roughness.

Efficient manufacturing technology. Three-dimensional printing is moving toward the development of large parts manufacturing technology, such as the direct manufacturing of aircraft titanium alloy frame bleeding structure with metal laser (length up to 6 meters, manufacturing time is too long), how to achieve simultaneous manufacturing of multiple laser beams, improve manufacturing efficiency, to ensure the consistency of material and regional quality is a difficult point of development.

In addition, in order to improve efficiency, the combination of three-dimensional printing manufacturing and traditional cutting processing, the development of three-dimensional printing and material removal composite manufacturing method is also the development direction and key technology.

AM technology companies do not need to carry out the traditional tool and fixture design and multiple processing procedures, in a device can quickly develop precision manufacturing of any one complex shape of the parts, thus enabling the parts "free manufacturing", solve many problems complex system structure analysis parts of the formation, and greatly reduce the information processing Work process, shorten the processing cycle. And the more complex the structure of the product market, the more significant the role of manufacturing speed.

Advanced manufacturing technology has become an important development direction of advanced manufacturing technology, its development trend has three aspects: (1) the application of precision casting technology in complex parts; (2) the directrapid prototyping types manufacturing of metal parts, the development direction of large aviation parts manufacturing; (3) to the direction of integrated organization and structure manufacturing. The key technologies that need to be addressed in the future include precision control technology, efficient manufacturing technology for large parts and manufacturing technology for composite parts. The development of AM technology will greatly improve the innovation ability of the aviation manufacturing industry and support the development of China from a large manufacturing country to a strong manufacturing country.

It is an important branch of 3D printing, which uses laser beam, electron beam, plasma or ion beam as heat source to heat materials to combine them and manufacture parts directly, which is called high-energy beam additive manufacturing and is most common in industry.

In the field of aerospace additive manufacturing technology, high-energy beam additive manufacturing of metal, non-metal or metal matrix composites is currently the fastest growing research direction.

The demanding service conditions such as high speed, high maneuverability, long endurance, and safety management for efficient and low cost operation have placed a higher quality requirement on the vehicle structure for design, material and manufacturing. Lightweight, monolithic, long life, high reliability, structural analysis and functional integration development and low-cost operation become a serious challenge for the society structural optimization design, materials application and manufacturing information technology personnel, which depends on the progress and innovation of structural system design, structural building materials and modern Chinese manufacturing science and technology.

Additive manufacturing technologies can change the existing forms of technology and promote the upgrade of manufacturing technology. A typical application of incremental manufacturing technologies to enhance existing manufacturing technologies is in the foundry industry. Additive manufacturing technology can increase production efficiency by tens of times and greatly improve product quality and consistency; additive manufacturing technology can be used for 3D printing of sand shapes for metal manufacturing. Significant improvements in production efficiency and quality have been achieved. In the foundry industry, it has become a trend to use incremental manufacturing to rapidly make molds.