3D printing technologyBelongs to a non-traditional processing technology, also known as additive manufacturing, rapid prototyping, is the rise of the global advanced manufacturing field in the past 30 years, a set of optical / mechanical / electrical, computer, numerical control and new materials in one of the advanced manufacturing technology. With the traditional manufacturing in material subtraction is different, 3D printing is practicing the code of addition, that is, through the powder, liquid sheet and other discrete materials layer by layer accumulation, "natural growth" into a three-dimensional entity, and then three-dimensional entity into a number of two-dimensional plane, greatly reducing the complexity of manufacturing. As long as the design of the structural model on the computer, you can quickly turn the design into a physical object, without the need for tools, molds and complex machining processes. 3D printing technology is particularly suitable for aerospace, weapons and equipment, biomedical, molds and other fields of small batch size, structural asymmetry, curved surfaces, and the content of structural parts (such as hollow blades of aircraft engines, human bone repair body, with the shape of the cooling waterway) rapid manufacturing, very consistent with the modern and future industrialization. Manufacturing, very in line with the modern and future trends of industrial manufacturing.

　　This year has seen a crescendo of discussions on the third industrial revolution. American scholar Jeremy? Rivkin said that the combination of the Internet and new energy will produce a new round of industrial revolution - this will be the third "revolution" after the 19th century steam engine and 20th century electrification. The Economist magazine also pointed out that the market potential of 3D printing technology is huge, and it is bound to become one of the many breakthroughs that will lead the future trend of manufacturing. These breakthroughs will enable factories to completely say goodbye to traditional tools such as lathes, drills, stamping presses, mold-making machines, and so on, and replaced by more flexible computer software dominates, which is the sign of the arrival of the third industrial revolution. Some statistics, in 2010, the total output value of the additive manufacturing 3D printing industry reached 1.325 billion U.S. dollars, an increase of 24.1% over the previous year, 2011 global revenue of 1.7 billion U.S. dollars, an increase of 2.94% over the previous year, it is expected that in 2012 will amount to 2.1 billion U.S. dollars, in 2015 to reach 3.7 billion U.S. dollars, and 2019 to reach 6.5 billion U.S. dollars.

　　The core manufacturing idea of 3D printing technology first originated in the United States in the late 19th century, but it was only in the late 1980s that 3D printing technology matured and was widely used. At present, the 3D printing industry in the United States, Japan, Germany and other countries is more developed. In China, engaged in 3D printing technology research institutions are few, and the 3D printing technology applications and industrialization of enterprises are only a few, Beijing Longyuan Automatic Forming System Co., Ltd. is with the implementation of the national high-tech research and development program in the 1990s and the emergence of the earliest one of the country's first 3D printing enterprises. Founded in 1994, Beijing Longyuan Automatic Molding System Co. Ltd. was founded in 1994, with a registered capital of 17 million. It successfully developed China's first SLS rapid prototyping equipment - AFS-360, and then devoted itself to the development of Selective Laser Powder Sintering (SLS, Selective Laser Sintering) rapid prototyping machine, and at the same time committed to rapid prototyping applications and processing services. Nowadays, its partners are spread all over the country, including many domestic research institutes and leading enterprises in the field of automobile manufacturing.

　　Beijing LongyuanFeng Tao, Chief Engineer, graduated from Tsinghua University, worked at the Institute of Polymer Materials, Tsinghua University, with rich theoretical and practical experience in polymer materials and laser optics, was the first to engage in China'sLaser rapid prototypingOne of the experts in technology research. He has deep knowledge about the application of 3D printing technology and materials. As early as 1995, he proposed the application of SLS to theRapid Precision Manufacturing. The most outstanding advantage of SLS over other 3D printer technologies is the wide range of molding materials it uses. Theoretically, any powder material that can form interatomic bonds when heated can be used as a molding material for SLS. Currently, the materials that can be successfully molded by SLS include paraffin, polymer, metal, ceramic powders and their composite powders, and SLS is suitable for a wide range of applications due to its variety of molding materials, material savings, and wide distribution of molded part properties, as well as the fact that SLS does not require the design and manufacture of complex support systems. Under his leadership, Beijing Longyuan has successively successfully developed complex process production methods such as casting molten molds, wax mold pressing and casting shells, as well as the application methods of polystyrene powder and synthetic materials in 3D printing.

　　For SLS molding materials, Feng Tao gave a detailed explanation.

　　Polystyrene is one of the earliest industrialized plastics, belongs to the amorphous polymers, it has low specific heat, fast heating flow and cooling curing speed, moderate melt viscosity, and better fluidity and thermal stability, which is beneficial to theSLS sintering molding. Polystyrene has no obvious melting point, the range of melting temperature is wide, about 95 ℃ began to soften, between 120 ℃ to 180 ℃ to become fluid, more than 300 ℃ began to decompose, releasing gases, to more than 380 ℃ will be violently decomposed. Polystyrene can be melted and bonded when heated, and can be cured and molded after cooling, and the material has a small moisture absorption rate, and the strength of the molded parts can be further improved by dipping the resin, and the main performance index can be up to the tensile strength ≥ 15MPa, bending strength ≥ 33MPa, impact strength ≥ 3MPa, which can be used as the prototype parts or functional parts, and it can be used as the mother mold for vanishing mold casting.

　　Ceramics, as an important structural material, has the advantages of high strength, high hardness, high temperature resistance, corrosion resistance, etc., whether in the traditional industrial field or emerging high-tech fields have a wide range of applications. However, the inherent advantages of ceramics, such as high strength and high hardness, but at the same time to the ceramic parts of the molding, processing brings a lot of difficulties, and thus ceramic powder is difficult to be directly sintered by SLS technology. In order to solve this problem, the commonly used method is to add organic binder, inorganic binder and metal binder. Beijing Longyuan Company proposes the method of preparing mesoscopic α-SiAlON ceramic rotor by SLS with Si3N4 (silicon nitride, the main component of a new type of ceramics) powder as raw material. That is, the surface of Si3N4 powder is modified with inorganic and organic twice coating, and then the blank is produced. The blanks produced in this way using binder-coated revered powders are stronger than those obtained by mixing binder and ceramics, and the molding accuracy and mechanical properties of the final parts are better.

　　Metal powder can realize the use of high melting point metal direct sintering molding parts, 3D printing technology in the use of traditional cutting and processing methods are difficult to create a wider range of high-strength parts has a particularly important significance. Feng Tao believes that SLS molding technology in the field of metal materials should be the research direction of the unit system of metal parts sintering molding, sintering molding of multiple alloy material parts, advanced metal materials such as metal nanomaterials, amorphous metal alloys, such as laser sintering molding, etc., is particularly suitable for the molding of micro components of cemented carbide materials. In addition, parts with functional gradient and structural gradient are sintered and formed according to the specific functional and economic requirements of the parts.

　　Coated sand using thermosetting resins such as phenolic resin to join the zircon sand, quartz sand produced by the method, the use of laser sintering method to produce prototypes can be directly used as a casting sand (core) to manufacture metal parts, of which the zircon sand has a better casting performance, especially suitable for non-ferrous alloys with complex shapes, such as magnesium, aluminum, and other alloys of the casting. Sand and low melting point polymer materials have two mixing methods, one is mechanical mixing, the other is the polymer material heating and melting, the sand pouring, stirring evenly, so that the sand surface covered with a layer of polymer material. Because of the good sintering performance of the coated sand, it is commonly used in the automobile manufacturing industry and aviation industry and other fields.

　　In addition, at present, Beijing Longyuan can successfully carry out SLS molding processing materials, such as paraffin, plastics and other new materials, composite powder materials, etc. SLS molding material varieties, material savings, molded parts with a wide range of performance distribution, plus SLS does not require the design and manufacture of complex support systems, suitable for a variety of purposes.

　　3D printing technology is now widely used in aerospace, and weapons, automotive and motorsports, electronics, biomedical, dental, jewelry, gaming, consumer and everyday products, food, construction, education and many other fields. It is foreseeable that the technology will be more inclined to the direction of daily consumer goods manufacturing, functional parts manufacturing and tissue and structure integration manufacturing. After 19 years of exploration and innovation, Beijing Longyuan has become a leader in the application of 3D printing technology in China and has made outstanding contributions to the take-off of China's aerospace, automotive, and other industries.

　　Aerospace: Aerospace products are characterized by complex shapes, small batch sizes, large differences in part specifications, and high reliability requirements, and the stereotyping of products is a complex and precise process that often requires multiple designs, tests and improvements, consumes large amounts of money, takes a long time, and is difficult to manufacture by traditional methods. Therefore, 3D printing technology has a unique application prospect in the research and development of modern aerospace products with its flexible and diverse process methods and technical advantages. Relying on its own technical advantages, Beijing Longyuan has provided helicopter engines, helicopter magazines, worm gear pumps, titanium frames, exhaust ducts (maximum height up to 2800mm), aircraft suspension parts, flywheel shells, and other aircraft parts for China's aerospace and other sectors and aircraft manufacturers: in 1996, the first commercial SLS rapid prototyping machine was sold to the Beijing Institute of Aeronautical Material Research and was successfully applied to the development of new products for military aviation. In 1996, the first commercialized SLS rapid prototyping machine was sold to Beijing Institute of Aeronautical Materials, and was successfully applied to the development of new products for military aviation; in 1999, the second generation of commercialized equipment, AFS-320, was successfully introduced to the market. The application of rapid prototyping is gradually unfolding, and we have participated in and completed the development and research tasks of several key national aerospace projects, such as: liquid oxygen-kerosene and liquid oxygen-liquid hydrogen engines for high-thrust rockets, and gyroscope frames for satellites.

　　Military industry: 3D printing technology and traditional manufacturing technology, compared with simple, easy to operate and other characteristics, especially for the processing of some new materials, the results are particularly significant. For example, aluminum alloy has been the most widely used metal structure material in the military industry. Aluminum alloy has the characteristics of low density, high strength, good corrosion resistance, high temperature resistance, etc. As a structural material, due to its excellent processing performance, it can be made into various cross-sectional profiles, tubes, high-bar plates, etc., in order to give full play to the potential of the material and to improve the stiffness of the components. Therefore, aluminum alloy is the preferred lightweight structural material for weapon lightweighting. By utilizing 3D printing technology, Beijing Longyuan has participated in and completed the development and research tasks of a number of national key projects in the military industry, such as the turbocharger of the new JS-II tank, the shell of infrared guidance instrument observation mirror, etc., thus further promoting the development of China's military industry.

　　Automobile manufacturing: With the development of China's automobile industry, automobile production is growing rapidly, and some key parts are becoming more and more complex, large-scale and lightweight, which requires the realization of parts of the overall and integrated manufacturing. However, the traditional process of making molds by sand-turning makes the molds more and more complicated and the number of live blocks increases dramatically, which to a certain extent restricts the development of China's automotive industry. In China, the technical team of Beijing Longyuan, which is leading the domestic 3D printing technology, has launched a research on 3D printing technology in the field of automotive engine manufacturing. SLS is a process that utilizes infrared laser beams to melt thermoplastic materials to form three-dimensional parts, and one of its most important features is that the molding process is independent of the degree of complexity, which makes it particularly suitable for the extremely complex internal structure of the engine block, cylinder head, intake and exhaust pipes and other components. components. In addition, SLS technology molding materials, especially with casting resin sand and disappearable mold material molding, therefore, can be combined with casting technology, rapid casting of engine parts. the combination of SLS technology and casting technology, derived from the rapid casting technology, can be effectively applied to engine design and development stage of the prototype of the rapid manufacturing. Its suitability for single-piece and small batch trial production and production characteristics, can quickly respond to the market and provide small quantities of products for testing and experimentation, help to ensure the speed of product development. The controllability of its molding process allows for low-cost, instantaneous modifications at the design development stage in order to check designs or provide assembly models. Helps to improve the quality of product development, its rapid prototyping raw material diversity, for the product development stage provides different process combinations, due to the localization of SLS raw materials and molding process can be organically combined with the traditional process, which helps to reduce the cost of development, the combination of the rapidity of the process, to support the increase in the frequency of the product replacement, and help to promote the product to enter the market as soon as possible.

　　Using 3D printing technology, Beijing Longyuan produces engine blocks, cylinder heads, gearbox shells, etc. for automobile manufacturers, not only with fast manufacturing speed but also with high precision, thus making the manufacturing of complex automobile parts digital, precise, flexible and green. Nowadays, the engines of many domestic high-speed railways, moving trains and subways can be seen in theProducts from LonrwonThe

　　Biomedicine: 3D printing technology is also currently being applied to the biomedical field, including bones, teeth, artificial livers, artificial blood vessels, and drug manufacturing. Beijing Longyuan cooperates with Peking University Stomatological Hospital, which transmits patients' CT scan data from CT workstation to PC through Magics software processing, burns and stores them in standard format (Dicom format), and then provides them to Longyuan, which develops and researches AFS-320 rapid prototyping machine accordingly. The equipment adoptsSelected Area Laser Powder Sinteringmethod, the raw material is polystyrene powder, which is made into a solid model, can be used in oral health care for symptoms such as zygomaticomaxillary bone fiber abnormal hyperplasia, and achieved good therapeutic effect. Meanwhile, in the treatment of obsolete zygomatic zygomatic arch comminuted fracture, the results of clinical application show good therapeutic effect. At present, Longyuan has a new direction in the medical field, i.e., professional rapid prototyping and rapid manufacturing solutions in the field of dentistry: CAD design of denture can be realized by using specific CAD software, including 3D design of dental base, crown, bridge, hooded crown, veneer, and dental onlay. With CAD design, rapid prototyping and rapid manufacturing of dentures can be automated, with high results, fewer consumables and lower costs.

　　At present, China has entered the critical period of building a moderately prosperous society in an all-round way and the period of deepening reform and opening up, accelerating the transformation of the economic development mode.The development of 3D printing technology has a series of strategic advantages, such as broad market prospects, low consumption of resources, large driving coefficients, many employment opportunities, and good comprehensive benefits, which can cultivate a batch of strategic emerging industry clusters on the basis of which is helpful to promote the upgrading of a batch of key industrial clusters. Industry clusters. We believe that Beijing Longyuan, as the earliest company to develop 3D printing industry in China, will continue to lead and stride forward in the future development of China's 3D printing industry by virtue of advanced technology, standardized management, perfect service and continuous innovation.