Development of the hottest precision and ultra pre

2022-08-01
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Development of precision and ultra precision machining technology

China is now a "large manufacturing country", with the manufacturing scale ranking fourth in the world, second only to the United States, Japan and Germany. In recent years, China has also made considerable progress in precision machining technology and precision machine tool equipment manufacturing. However, China is not yet a "manufacturing power", and there is still a big gap compared with developed countries. At present, foreign countries have developed a variety of precision and ultra precision turning, grinding, polishing and other machine tools, and developed new precision machining and precision measurement technologies. In order to ensure that China's national defense and scientific and technological development are not controlled by others, we must invest the necessary human and material resources to independently develop precision and ultra precision machining technology, and strive to raise China's precision and ultra precision machining technology to the world advanced level as soon as possible. The latest development of precision and ultra precision machining technology at home and abroad is introduced as follows

development of precision machine tool technology

precision machine tool is the basis of precision machining. Nowadays, the development direction of precision machine tool technology is: on the basis of continuing to improve the accuracy, high-speed cutting is used to improve the machining efficiency, and advanced numerical control technology is used to improve the development process of its self process measurement and control instruments. There has been a major turning point and a rare opportunity for automation. Dixi company of Switzerland is famous for producing horizontal coordinate boring machines. The dhp40 high-precision horizontal high-speed boring machine produced by the company has added a multi axis CNC system to become a machining center; At the same time, in order to realize high-speed cutting, the maximum speed of the machine tool spindle has been increased to 24000r/min. The maximum spindle speed of the high-speed precision five axis machining center of mikrom company in Switzerland is 42000r/min, and the positioning accuracy reaches 5 μ m. The accuracy of the coordinate boring machine in the past has been reached. From the performance of these two machine tools, it can be seen that there is no longer a strict boundary between machining centers and high-speed cutting machine tools

ultra precision cutting technology using diamond tools

progress in ultra precision cutting technology

ultra precision cutting technology with diamond tools is an important part of ultra precision machining technology. Many national defense cutting-edge product parts (such as gyroscopes, various planar and curved mirrors and lenses, precision instruments and meters, and various parts in high-power laser systems, etc.) need to be processed by diamond ultra precision cutting

ultra precision cutting with single crystal diamond tools on ultra precision machine tools can produce highly polished mirrors. The cutting thickness of ultra precision cutting can be very small, and the minimum cutting thickness can reach 1nm. The single crystal diamond tool used in ultra precision cutting requires a sharp edge with a radius of 0.5 ~ 0.01 μ m。 Because the radius of the cutting edge is very small, it was very difficult to measure the cutting edge in the past. Now it can be easily measured by atomic force microscope (AFM)

research on the mechanism of ultra precision cutting

the research on the mechanism of ultra precision cutting has made a lot of progress in recent years. For example, in ultra precision cutting of brittle materials, the machined surface can obtain a mirror without brittle fracture marks, which involves the brittle plastic transformation of plastic removal of brittle materials in very thin cutting. Recently, many new ideas have been put forward. It can be seen from the experimental results of ultra precision cutting glass that the cutting thickness is very small at the beginning, the cutting mechanism is plastic removal, and there is no brittle damage trace on the machined surface. With the increase of cutting thickness, plastic cutting gradually turns into brittle fracture removal, and obvious brittle damage traces can be seen on the machined surface

at present, computer simulation and molecular dynamics simulation have been used to study the process and mechanism of ultra precision cutting. On the one hand, they have deepened the understanding of the removal mechanism of very thin layer materials, and can make a more accurate prediction of the effect of ultra precision cutting. From the computer simulation prediction and computer simulation prediction of the machined surface formed by ultra precision cutting, it can be seen that the cutting forces in different directions are not equal due to the anisotropy of the crystal. Using the molecular dynamics simulation of ultra precision cutting process, the dynamic cutting process of ultra precision cutting very thin materials can be observed and analyzed, and the cutting process can be demonstrated by animation

a new crystal orientation method for diamond tools

due to the high hardness and crystal anisotropy of diamond, the grinding of single crystal diamond tools is very difficult. It is necessary to orient the crystal when manufacturing diamond tools and grinding. In the past, the crystal orientation method mainly used X-ray crystal orientation instrument. The instrument is expensive and the orientation operation is quite cumbersome. Harbin Institute of technology has successfully developed a new laser crystal orientation method. The equipment used is simple and the orientation operation is convenient, which can greatly simplify the orientation of diamond crystals

progress of ultra precision machining machine tools

development of ultra precision machine tools abroad

research and development of ultra precision machine tools is an important prerequisite for the development of ultra precision machining. In recent years, developed countries have successfully developed a variety of advanced ultra precision machining machines. The development direction of ultra precision machine tools is to further improve the accuracy of ultra precision machine tools, develop large ultra precision machine tools, and develop multi-functional and efficient special ultra precision machine tools

the United States, Britain, Germany and other countries began to produce ultra precision machine tools in the 1970s (Japan in the 1980s) and can supply them in batches. In terms of precision machine tools, the rapid development of large-scale electric vehicles in China has driven the rapid growth of lithium diaphragm industry. In 1986, LLL National Laboratory in the United States successfully developed two large-scale ultra precision diamond lathes: one is a horizontal dtm-3 diamond lathe with a diameter of 2.1m, and the other is a lodtm vertical large-scale optical diamond lathe with a diameter of 1.65m. Among them, lodtm vertical large-scale optical diamond lathe is recognized as the ultra precision machine tool with the highest precision in the world. Later, the United States developed a large 6-axis CNC precision grinder for precision grinding of large optical mirrors

Britain's Cranfield precision machining center successfully developed oagm-2500 multi-functional three-axis CNC grinding machine (workbench area 2500mm) in 1991 × 2500mm), which can be used for machining (grinding, turning) and measuring precision free-form surfaces. The machine adopts the method of assembling machined parts, and can also process large mirrors with a diameter of 7.5m in astronomical telescopes

Japan's multi-functional and efficient special ultra precision machine tools have developed rapidly, which has played a good role in promoting the development of Japan's microelectronics and home appliance industry

development of China's ultra precision machine tools

for a long time in the past, due to the embargo restrictions of western countries, China's import of foreign ultra precision machine tools was seriously restricted. However, in 1998, it took almost 30 years for China's own CNC to completely replace wood ultra precision machine tools in American Bridges from 1880s to 1910. After that, western countries immediately banned China, and China has now imported many ultra precision machine tools

China's Beijing Machine Tool Research Institute, Aviation Precision Machinery Research Institute, Harbin Institute of technology and other units have now been able to produce several kinds of ultra precision CNC diamond machine tools, such as the ultra precision lathe developed by Beijing Machine Tool Research Institute to process 800mm diameter and the ultra precision lathe developed by Harbin Institute of technology to provide customized solutions for customers. These two machine tools have two coordinate precision CNC systems and two coordinate laser measurement systems, It can process non spherical surfaces of revolution; In addition, Harbin Institute of technology has developed an ultra precision milling machine for machining large planes of KDP crystals. KDP crystal can be used for optical frequency doubling and is an important component in high-power laser system. Must admit, in the super? In terms of dense machine tool technology, we still have a considerable gap compared with the advanced level of foreign countries, and the quality level of domestic ultra precision machine tools needs to be further improved

in terms of large-scale ultra precision machine tools, at present, the United States, Britain, Russia and other countries have large-scale ultra precision machine tools developed by themselves. However, China has no large-scale ultra precision machine tools, so it is unable to process large-diameter curved surface reflectors and other large-scale ultra precision parts. Foreign countries have strict restrictions on the export of these large-scale ultra precision parts, which has seriously affected the development of China's national defense cutting-edge technology. At present, China is stepping up the development of vertical ultra precision machine tools with a diameter of more than 1m

in terms of multi-functional and efficient special ultra precision machine tools, China is still basically blank at present

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