Abstract Low carbon, green and environmental protection are global eternal topics. High speed, high efficiency, ultra-fine and mechanized, automated and intelligent are the great goals pursued by modern industrial enterprises. As a developing high-tech superhard material, it is a great use in this magnificent modern industrial revolution...
Low carbon, green and environmental protection are global eternal topics. High speed, high efficiency, ultra-fine and mechanized, automated and intelligent are the great goals pursued by modern industrial enterprises. As a developing high-tech superhard material, it is of great use in this magnificent modern industrial revolution. The question now before us is how to serve the modern industry and make a bigger, newer contribution. This year marks the 50th anniversary of the successful development of China's first cubic boron nitride. It coincides with the first year of the 13th Five-Year Plan. We will focus on the future development goals around the above-mentioned ambitious goals and the national strategy. The following is a quote from a number of experts in the field of superhard materials. From different professional perspectives, they come up with different ideas or suggestions for what to do in the next few years or longer. 1. For the development of high-speed and ultra-high-speed grinding technology, Lv Zhi, Jiang Yanlin and others believe that the research on domestic abrasive tools should focus on the following aspects for technological innovation.
1.1 Technical innovation of binding agent
On the basis of considering the low temperature and high strength, the wear resistance and shape retention of the bonding agent should also be considered. At present, nanotechnology is used in China to increase the strength of the binder and to better integrate with the abrasive grains. It has also been reported abroad that a special resin is used on the basis of the ceramic binder to enhance the strength of the binder to improve the fatigue performance of the binder around the abrasive particles after repeated loading.
1.2 Innovation of molding technology
Different molding methods, the abrasive grains and the binder are different in the molding process, and the uniformity of the formed tissue is also different.
1.3 Detection technology innovation
At present, the detection of high-speed and ultra-high-speed abrasive tools is basically the same or even less than that of conventional conventional abrasive tools. For example, hardness testing has not yet seen relevant standards.
2, Zhang Lili, Lin Feng and other suggestions for the development of domestic PcBN products.
2.1 Expanding the diameter of PcBN products
The expansion of the diameter of PcBN products is not only a matter of product size, but also puts forward higher requirements for the integrated technology of PcBN synthesis. Expanding the diameter of PcBN products has brought about a series of technical problems, including the requirement for large equipment and the expansion of cavity space, resulting in an increase in temperature difference and pressure difference in the cavity, which in turn leads to product performance uniformity.
In addition, the enlarged cavity space requires a longer sintering time, so the stability of the cavity assembly is more demanded. To expand the diameter of the PcBN product, it is necessary to ensure that the PcBN product has good cutability, and the PcBN product can be cut into the same. Any shape needed to reduce unit cost and improve overall efficiency.
2.2 Refine the granularity of cBN
The refinement of cBN grains can improve PcBN wear resistance, impact resistance and processability. However, as the grain refinement, it will bring difficulties to the production process, such as uneven mixing, which causes enrichment and segregation of the binder in PcBN, resulting in uneven PcBN structure and unstable performance.
In addition, the smaller the cBN particles, the smaller the gap between the cBN particles, which makes the bonding agent difficult to penetrate, resulting in uneven sintering penetration and affecting the overall performance of the PcBN.
2.3 Strengthen product serialization research work
PcBN products in western developed countries are developing in a series and diversified manner. PcBN products with different properties are provided according to different processed materials and different processing methods. The particle size ranges from 0.3μm to tens of microns, and the cBN content ranges from low to high. The content of the binder is from metal to non-metal mixed materials. Although the domestic PcBN product serialization work has been carried out for many years, there are not many research institutes and universities in China, and the production enterprises do not have the technical strength in this respect. As a result, the application basic research of domestic PcBN products is not deep enough and insufficient. system.
Therefore, the domestic research work of PcBN product series industrialization must be strengthened, the serialization process of PcBN products should be accelerated, the national unified PcBN industrial standard should be formulated, and product standardization and serialized management should be implemented to make it process different materials and under different conditions. Give full play to the advantages and meet the requirements of different materials processing in China.
2.4 Pay attention to the role of tool coating and increase the research and development of tool coating technology
Because of the comprehensive performance of the coated inserts, the coated inserts have better versatility. Tool coating technology in developed countries has developed rapidly and is widely used. Compared with domestic, the gap is very large, and the number of coated tools is also very far, accounting for about 20% of all tools. Among them, CNC machine tools and machining centers use much more, and on ordinary non-CNC machines, they are pitiful because of problems and prices. We should strive to improve the level of tool coating technology and application technology, and promote the application of coated tools to promote the improvement of cutting and mechanical manufacturing.
3, 寇自力, Li Yu and other talk about the future development direction of PcBN pointed out that reviewing the history of China's superhard materials development, carefully consider the slow development of China's PcBN tool blank material and the reason why high-speed cutting superhard tool technology is difficult to promote, the future PcBN knife The development direction of the billet should have the following characteristics:
3.1 First of all, it is necessary to strengthen the research on the theory of superhard material sintering and the theory of superhard tool cutting;
3.2 Further improve the pressure and temperature limit of the domestic six-face press, and better grasp the precision control technology of the high temperature and high pressure chamber;
3.3 PcBN tool blank material should be developed in size and product serialization, and the quality stability and performance should be uniform.
The development of super-hard tools: (1) increase the introduction and digestion of imported CNC super-hard tool manufacturing equipment, realize the manufacture of micro-scale precision super-hard tools; (2) strengthen the promotion and application research of super-hard tools, develop super-hard tools New application areas, the transformation from Chinese manufacturing to China's creation; the establishment of PcBN tool industry standards and international standards.
4, Li Zhihong, Feng Dandan, etc. in the "Ceramic Bonding Agent cBN Abrasives Status and Development Countermeasures" pointed out:
The development of ceramic bond abrasives is an inevitable trend. In order to meet the needs of the development of cBN abrasive tools, the following aspects should be done:
4.1 Continue to develop high-performance bonding agents to meet the needs of ultra-high-speed grinding development; form a series of bonding agents to meet the needs of different grinding applications. The development of binding agents should follow several basic principles that have been summarized.
4.2 Strengthen the further study on the bonding mechanism of abrasives and binders, explore new methods for surface modification of cBN abrasives, and strive to achieve reasonable design and controllability of bonding interface between abrasive and abrasive.
4.3 Strengthen the research of cBN grinding tools in the grinding of difficult-to-machine materials such as ultra-high speed grinding and aerospace, and broaden the application range of domestic cBN abrasive tools.
4.4 Strengthen collaborative innovation research in several aspects of production, education and research. On the one hand, grinding is a systematic project, which requires a good combination of machine tools, grinding tools and grinding applications. On the other hand, there is no research unit and grinding wheel production unit in China that has a considerable level of grinding test center, many Performance verification needs to be done on the user side. For large-scale grinding production, it has been verified that the abrasive research and manufacturing units generally do not have enough work even if they have a grinding test platform, and still rely on the grinding production unit. If the user does not test in time, the progress of the development and adjustment of the abrasive tools will be delayed.
5, Zhang Xiangfa, Zhang Kui in the "China's high-quality cubic boron nitride single crystal status and development trend" mentioned in the text: China's cBN development prospects are good.
"Global Strategic Business Report: cBN Abrasives" published by Global Industry Analysis states that cBN is becoming the abrasive of choice for most grinding applications because it helps to achieve precise geometry and size, better surface finish and surface Integrity, as well as reduced processing time. Because it is very suitable for use on CNC grinding machines, its use is increasing. In order to take full advantage of cBN grinding and obtain better surface finish, structural integrity and longer service life, more and more car manufacturers have chosen cBN grinding wheels to replace traditional abrasive grinding wheels.
The biggest application of cBN products is in the manufacture of cBN grinding wheels. Among the four binders (resin, ceramics, metal, electroplating) of cBN grinding wheels, cBN grinding tools with ceramic bonding agents have developed fastest. Worldwide, the proportion of ceramic cBN abrasives has increased from 4% in the 1980s to more than 50% today, and the growth rate is rapid. Ceramic cBN grinding tools have the advantages of high grinding efficiency, good shape retention, high durability, easy dressing, high abrasive utilization rate (more than 75%, other types of bonding agent is 50-60%), long service life of grinding wheel, etc. Therefore, it is the first choice for efficient and high-precision grinding. Applications include automotive, aerospace, oil pump nozzles, compressors and more. In recent years, cBN application promotion has made great progress, and the use of manufacturers has increased rapidly. According to incomplete statistics, there are more than 500 manufacturers of cBN single crystals in China, and the use of single manufacturers is more than 4 million carats.
In addition, the domestic PcBN tool has experienced many years of development, and has now formed a certain scale. In particular, the rapid development of the overall PcBN tool has led to a significant increase in the use of cBN micropowder. Several manufacturers of cBN single crystals have been added to the synthetic PcBN to varying degrees. This ranks, which also led to a steady increase in the production of cBN single crystals. In summary, the development prospects of China's cBN will continue to improve.
6. Chen Yongjie, Wang Haikuo and others believe that with the further development of industrialization process, the emergence of new difficult-to-machine materials, the advantages of PcBN tools are becoming more and more obvious, and PcBN tools will have a broader market prospect. Direction development:
6.1 The new preparation process and method are mainly to upgrade the traditional preparation process and method to meet the requirements of the preparation process and method under the new situation;
6.2 Lower manufacturing cost and low-carbon environment are mainly to improve the utilization rate of raw materials in various production links, as well as the recycling of tools, and strive to achieve the lowest cost and no pollution;
6.3 New Fields With the continuous emergence of new materials, higher requirements are required for the various properties of the tools, so their application fields are bound to be further developed.
7. Yin Hong pointed out in the paper "Research Progress and Application of Cubic Boron Nitride Films":
cBN has extremely high hardness and good wear resistance, its hardness is second only to diamond, and its thermal stability and chemical stability are far superior to diamond. In addition, cBN has high bandgap, high thermal conductivity, good insulation, and good light transmission from ultraviolet to infrared including visible light. cBN has great application potential in the fields of machinery, electronics and optics. However, at present, there are still some basic problems in the research of cBN, such as high internal stress of film, poor adhesion of film base, high deposition temperature, low deposition rate and unstable cubic phase content. In recent years, great progress has been made in the deposition and epitaxial growth of cBN thick films, but the application in superhard products is still mainly in the form of copolymer crystal micropowder. Therefore, the development of high-end cBN coated products is a focus of industrial applications. One of the main problems. In addition, it is also necessary to actively develop applications of cBN films in other emerging fields, such as biology, optoelectronics, and semiconductors.
8. Zhang Tiechen in the "Synthesis of high-quality cBN single crystal propulsion function characteristics" text : Expand cubic boron nitride current control differential negative resistance, second-order non-linear optical properties, linear electro-optic coefficient and cubic boron nitride single crystal-diamond The study of membrane heterogeneous PN junctions will broaden the research field of cubic boron nitride single crystals, and has important significance for the research of cubic boron nitride crystals in optoelectronic devices. However, due to the limitation of the size of the cubic boron nitride single crystal, many work cannot be carried out. Therefore, it is still an urgent problem to synthesize a cubic boron nitride single crystal of high quality, large size and regular shape. Whoever breaks through this obstacle first will seize this opportunity. Let us work together to get this day to come soon!
9. Dong Shushan, Zhou Xiaoyan, etc. in the article "Development Status and Future Prospects of Metal Bonding Agents for Superhard Materials" : "Efficient, energy-saving, green and environmentally friendly" will be the main theme for the development of superhard materials products industry in the future. The advancement of materials has promoted the innovative breakthroughs in the preparation mechanism and process equipment of the products, from the single driving force to the direction of the "pressure + temperature" two-phase driving force, the strengthening pressure as the driving force, and the weakening temperature as the driving force. . "fine particles, high activity, easy to suppress, stabilize, and functional" will be the future development direction of metal bond. The development of metal bond should be carried out around the two main lines of “holding power†and “wearingâ€, and carry out innovative research on composition design, refinement means, activity control, particle size distribution, repressive regulation, etc., and carry out in-depth development of the carcass. The basic research related to microstructure, microstructure, sintering mechanism and material properties, and then the development of related process equipment.
10. Thinking about future development
Focusing on the above-mentioned ambitious goals and the national political strategy, the author believes that the future development goals are summarized as follows.
10.1 Development towards “three highs and one low†(ie high speed, high efficiency, high precision, low cost)
With modern industrial technology and high-performance technology products, the requirements for machining precision, surface roughness, surface integrity, processing efficiency and batch quality stability of mechanical parts are getting higher and higher.
Ultra-high-speed grinding technology is a high-level integration of modern new material technology, manufacturing technology, control technology, testing technology and experimental technology. It is a perfect combination of high quality and high efficiency. It is a revolutionary revolution in grinding technology and is known as “modern grindingâ€. The highest peak of cutting technology."
High-speed / ultra-high speed, high efficiency, automation / CNC / intelligent, ultra-precision, etc. is not only the main content of current abrasive processing technology, but also an important frontier of advanced processing and manufacturing processes and equipment.
Ceramic cubic boron nitride grinding wheel is a high-performance abrasive tool with high speed, high efficiency, high precision, low grinding cost and low environmental pollution. It has become a hot spot in the world for competitive research and development and an important direction for the development of contemporary abrasive products. In the United States, Japan, Germany, the United Kingdom and other industrial developed countries, aerospace, bearings, automobiles, tools and other industries have entered the stage of scale application or popularization. Therefore, it is necessary to increase the research and development of high-grade cBN ceramic grinding wheels and expand its application fields.
10.2 Development towards the direction of “three high and one specialâ€
The aerospace industry is known as "a jewel in the crown of the industry". Due to the complex shape and structure of aerospace products, various materials and strict processing precision, it has always been one of the industries with high level of advanced technology.
As a necessary supporting equipment for CNC machine tools, metal cutting tools have entered the development stage of “CNC tools†driven by CNC machining technology, showing “three high and one special†(ie high efficiency, high precision, high reliability). And specialization) features.
New cutting processes such as dry cutting and hard cutting, which are represented by high-speed cutting, have shown many advantages and strong vitality, and have become the main way for aero-engine manufacturing technology to improve processing efficiency and quality and reduce costs. The main contradiction in the machining of aerospace hard-to-machine materials has shifted from being able to cut machining to high efficiency and low cost.
The main structural components such as blades, disc shafts and casings of advanced engines use a large number of new ultra-high-temperature high-temperature resistant alloys, single crystal alloys, intermetallic compounds and lightweight high-strength composite materials, which adds more difficulty to mechanical cutting. Higher requirements are placed on cutting technology. Therefore, our space shuttles, spaceships, space probes, and other great inventions that condense human diligence and wisdom must rely on high-precision knives to fly higher and fly farther. Therefore, the development of a new generation of PcBN tools and industrialization is the mission of the times.
10.3 Development towards functional applications
The cubic boron nitride crystal has a wide band gap of 64 eV, which is a very excellent semiconductor material and has broad application prospects in the field of high temperature and high power broadband device microelectronics. Cubic boron nitride can produce second-order nonlinear optical effects, which can be used for light harmonic generators, photoelectric modulators, visible ultraviolet light converters, optical rectifiers, optical parametric amplifiers, and the like. In addition, cubic boron nitride, like diamond, has a strong æŠ radiation capability and can be used in radiation resistant devices. Therefore, it has important practical significance for the functional research and development of cubic boron nitride materials.
With the research and development of cBN large single crystals, cBN single crystals are irregular in shape and small in size, which seriously restricts the research and application of the basic properties of cBN crystals. On the one hand, large-size high-quality cBN single crystals are used to prepare single-crystal cutters with excellent performance; on the other hand, in the study of functional materials, large-sized CBN single crystals are necessary for studying the basic properties of heat, electricity and light, and at the same time It is also necessary to prepare heat sinks, high temperature semiconductor devices and even special optical devices.
10.4 Strengthen product serialization research work
PcBN products in western developed countries are developing in a series and diversified manner. PcBN products with different properties are provided according to different processed materials and different processing methods. The particle size ranges from 0.3μm to tens of microns, and the cBN content ranges from low to high. The content of the binder is from metal to non-metal mixed materials. However, although the domestic work of PcBN products has been carried out for many years, there are not many research institutes and universities in China, and the production enterprises have no technical strength in this respect, which leads to insufficient application of basic research on domestic PcBN products. Not enough system.
Therefore, the domestic research work of PcBN product series must be strengthened, the serialization process of PcBN products should be accelerated, the national unified PcBN industry standard should be formulated, and product standardization and serialized management should be implemented to make different materials and under different conditions. Give full play to the advantages and meet the requirements of different materials processing in China.
Development and industrialization of 10.5 cubic boron nitride coated abrasives
China is a big producer of coated abrasives, but the proportion of cubic boron nitride coated abrasives is very small. In order to meet the development of modern grinding technology, the need for hard and brittle material grinding and polishing, we must vigorously develop cubic nitrogen. Boron coated abrasives and industrialized
10.6 Strengthening research on applied technologies
Strengthen the research of cBN grinding tools in the grinding of difficult-to-machine materials such as ultra-high-speed grinding and aerospace, and broaden the application range of domestic cBN abrasive tools.
Strengthen the promotion and application research of super-hard tools, develop new application fields of super-hard tools, and realize the transformation from Chinese manufacturing to Chinese creation.
With the development of modern cutting technology, in order to increase the cutting speed and reduce the cutting cost, the most economical method among all processing factors is to apply new materials and new processes. Surface coating is an effective means to improve tool life and reduce cutting cost. It can not only improve the surface hardness of the tool, but also enhance its wear resistance. It can also reduce the surface friction coefficient of the tool, increase the lubrication ability, increase the cutting speed and reduce the tool change. The number of times improves the accuracy and surface quality of the machined parts, thereby increasing production efficiency.
In view of the quality and composition of the currently synthesized cBN coatings, it can only be used for tooling products with lower coating requirements. Many companies in the United States and Japan have invested heavily in this area. It is expected that the market for super-hard coated tools will continue to expand in recent years, and its application areas are mainly concentrated in the automotive industry.
Due to its small particle size, large specific surface area, low sintering temperature, high strength and good toughness, nano-ceramic binders are expected to solve the contradiction between the low sintering temperature and strength of traditional ceramic binders and improve the ceramic bond cBN grinding wheel. Performance, further broaden the application range of cBN grinding wheel.
10.7 Strengthening the exploration of process technology theory
cBN has potential applications in the fields of semiconductors, optoelectronic devices and flat panel displays. Since the intrinsic cBN has a very high resistivity and is close to the insulator, in order to apply it to the field of electronics, it is necessary to perform suitable doping to adjust its electrical properties. Theoretical calculations show that Be and Mg replace B atoms in cBN to form p-type conductivity, while Si and C replace n-type conduction in cBN to form n-type conductivity.
With the successful implementation of cBN thin film epitaxial growth, it is possible to apply cBN to high-temperature high-frequency semiconductor devices, which is accompanied by an effective preparation method for exploring high-quality, defect-free, impurity-free, and doped tunable cBN epitaxial films.
First of all, we must strengthen the research on the theory of superhard material sintering and the theory of superhard tool cutting.
10.8 bonding agent as the main component of superhard material abrasives, the core of its development is to improve the microstructure of the sintered carcass, including microstructure, sintering density, sintering strength, sintering hardness, wear properties, infiltration of superhard materials Sex, high temperature hardness, etc.
In recent years, nano ceramic bond has been explored. The nano-ceramic binder should be a binder of nano-sized inorganic particles as the main phase. Nanomaterials exhibit significant small size effects, quantum size effects, and surface interfacial effects due to their small particle size and large specific surface area. Compared with traditional ceramic bond materials, nano ceramic bond should have high strength, good toughness and low sintering temperature. However, due to its low density, it may cause certain difficulties in the formation of abrasive tools. In addition, the nano ceramic powder is easy to prepare, but since the ceramic particles grow up during the sintering process, it is not easy to obtain a nano ceramic structure material in the true sense. Therefore, true nano-ceramic binders are hard to see on the market.
10.9 Establish high-tech standards with international standards
Our current cBN basic varieties and derived varieties have reached dozens, but currently there are only 2 national standard cBN varieties, far less than the actual product variety, which has caused the abrasive manufacturers to communicate with the grinding wheel manufacturers and accept them. Inconvenience, it is urgent to expand the standard series of cBN products in China.
Domestically, we must strengthen the serialized basic research work of PcBN products, accelerate the serialization process of PcBN products, formulate national unified PcBN industrial standards, implement product standardization and serialized management, and make it to maximize the advantages in processing different materials under different conditions. To meet the processing requirements of different materials in China.
10.10 Establish a coordinated mechanism for coordinated development
Strengthen collaborative innovation research in several aspects of production, education and research. Only a few aspects can cooperate with each other to achieve rapid innovation of grinding machines, grinding tools and grinding technology, in order to quickly realize the industrialization process of machine tools and abrasive tools, and at the same time bring high speed, high efficiency, high precision and low for grinding application units. The cost of grinding benefits.
It can be seen that concentrating the superior strength of the various legions can fight the battle against annihilation and speed, and achieve a win-win and good outcome of common development, common improvement, and common benefits.
bbq grill, bbq grill mesh, Grill Grate, stainless wire bbq grill,Bbq Grill Metal Mesh,etc. It is suitable for indoor and outdoor barbecue.
Barbecue wire grill grate is made of high quality 304 stainless steel, never rusting and durable. BBQ Wire mesh does not have any coating or chemical ingredients, making food safer.
Barbecue wire grill grate is made of high quality 304 stainless steel, never rusting and durable. BBQ Wire mesh does not have any coating or chemical ingredients, making food safer.
bbq grill mesh,stainless wire bbq grill,Bbq Grill Metal Mesh,cooking grate,bbq grill grates stainless steel
Shenzhen Lanejoy Technology Co.,LTD , https://www.wire-spring.com