Application and development of the hottest high en

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Application and development of high-energy beam processing technology

high energy beam processing technology uses high-energy density beams (electron beams, lasers, ion beams, etc.) as heat sources and materials, so as to achieve material removal, connection, growth and modification. High energy beam machining technology has unique technical advantages and is known as one of the advanced manufacturing technologies in this century. It has been paid more and more attention and its application field has been expanding. After years of development, high-energy beam machining technology has been applied to welding, surface engineering and rapid manufacturing, and has played an important role in aviation, aerospace, shipbuilding, weapons, transportation, medical and many other fields

development of high-energy beam source quality

the application and development of high-energy beam processing technology are closely related to the quality of high-energy beam source. With the continuous development of science and technology, whether it is an electron beam or a laser beam, the beam quality is getting better and better, the energy density, power and other parameters are getting higher and higher, and the processing capacity and processing quality are improved

electron beam quality mainly has two connotations: first, the stability of beam current and high pressure; The second is the beam shape and energy distribution. The former mainly depends on the high-voltage power supply and the corresponding control system; The latter mainly depends on the electron gun and its electromagnetic focusing system

high voltage power supply is an important part of electron beam processing equipment. Since the 1950s, the design and manufacturing technology of high voltage power supply has gone through three stages, namely, power frequency transformer, medium frequency generator set and high frequency switching power supply. In each development stage, the performance of high-voltage power supply has been greatly improved, especially the switching high-voltage power supply, which has a wider range of high-voltage regulation, higher effective power, high-voltage ripple and smaller equipment volume. At present, each part of the high-voltage switching power supply has realized the high-frequency working mode. Generally, under the condition of full-scale beam, the beam stability reaches ± 0.25%, and the high-voltage stability reaches ± 0.25%

the beam shape and energy distribution mainly depend on the electron gun, which will also give the extruder industry endless development power and its electromagnetic focusing system. At present, there is no exclusive quantitative index. Generally, the energy distribution of different cross sections of the beam can be measured to analyze whether the beam shape and energy distribution are good. At present, the technology of electron beam generator (electron gun) has developed rapidly, from low-voltage and small power type to high-voltage and large preparation. However, the ban may save a piece of forest power type in different delivery packages (as shown in Table 1), which greatly improves the processing capacity and quality, and expands the technical means of electron beam processing

the research and development of high-voltage electron beam welding equipment in China started late, mainly because the design and manufacturing technology of electron gun and high-voltage power supply in high-voltage electron beam processing equipment is difficult, and the test is not easy to carry out. At present, there are many researches on electron beam welding equipment in China, but they are mainly limited to the research on medium voltage and low-power electron beam welding machines, and the research on high-voltage and high-power equipment is relatively small. At present, the problems of high-power high-voltage power supply and high-voltage electron gun have been solved. The Key Laboratory of national defense science and technology has carried out systematic and in-depth research on high-energy beam processing technology and achieved certain results. The high-voltage and beam stability of high-voltage power supply have reached ± 0.25%. At the same time, a new type of electron beam energy density measurement device has been developed to carry out the research and improvement of relevant electron guns

the continuous emergence of new lasers and the continuous improvement and perfection of technology have effectively promoted the application of laser technology in various fields. Especially after the middle and late 1980s, the performance of nd:yag lasers and CO2 lasers has been further improved, and the output power has increased to kW and 10000 watts, which has further expanded the application scope of laser processing technology of materials, especially the laser welding technology has changed from heat conduction welding to deep penetration welding, Fundamental changes have taken place in the welding mechanism and principle

in foreign countries, the CO2 laser processing system with an output power of about 10kW has become a conventional welding equipment stably applied in various industrial departments. In terms of the application of high-power laser welding, the French Welding Research Institute installed and completed the commissioning of 45KW CO2 laser in 1993, and is carrying out the basic research work of large thickness (40 ~ 50m m) single pass welding technology. In 1994 and 1996, the Kinki Institute for advanced materials processing in Japan and Japan iron and Steel Corporation also completed the installation of 45KW CO2 lasers. At the same time, the output power of YAG laser welding system has also been greatly improved, and the commercialized equipment with an output power of 4kw has been introduced to the market

in China, laser material processing technology has experienced a history of more than 30 years. After several five-year plans of the state, laser processing equipment has been developed from scratch, and the output power has been increased step by step. Many other units have the ability to produce 2 ~ 10kW CO2 laser series products, and can also manufacture YAG solid-state lasers below kilowatt level. However, compared with foreign countries, the beam quality is poor, and the reliability and stability of components need to be further improved

at present, the performance of nd:yag laser and CO2 laser is further improved. For nd:yag laser, in order to overcome the serious thermal lens effect during high-power operation and improve the output power and beam quality of the laser, new laser structures such as slab and tube have been developed; In addition, optical fiber transmission greatly improves the flexibility of welding operations. At the same time, the CO2 laser is changed from the original cross flow structure to the fast axial flow structure, and the output power is greatly improved; The establishment of RF and microwave excitation modes reduces the volume of CO2 laser and improves the efficiency and modulation

in the 1990s, the emergence of diode pumped solid-state lasers has greatly reduced the volume of lasers, high beam quality, long service life, and pump efficiency far beyond the lamp excitation mode. It is a promising new laser processing energy, which will replace the existing laser processing equipment to a great extent

in recent years, some new lasers have entered the field of laser processing (such as excimer lasers, emission 5 μ M), which will expand the new field of laser welding equipment and promote the development of laser processing technology. In particular, the emergence of fiber lasers, whether beam quality or output power, should be said to be a revolutionary change in laser processing technology

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