The gloom of the global financial crisis has not faded. When the world's aviation manufacturers are still struggling to jump in the pattern and out of the crisis, the Paris Air Show has been grandly debuted, and all aviation companies are competing for "competition". Let out all the tricks to show off the various stunts.
However, supporting these aerospace manufacturing giants at the show is advanced metalworking manufacturing technology and machine tool equipment. Today, the world aerospace manufacturing industry is not only a competition for manufacturing technology, but also a competition for machine tool companies. The various special materials involved in aerospace manufacturing are based on the absence of advanced machine tools, and there is no progress and development in the world aviation industry. So, what are the main materials used in aerospace manufacturing today? What is the difference between the characteristics of materials and the performance of other industries? What is the difference between tools and machine tools used in metal processing and general metal processing? To this end, we are fortunate to have invited first-line engineers specializing in metal cutting, equipment repair and material application research in aerospace manufacturing, in "Metal Processing" and China Metal Processing Online Theory "Sword".
Spear is not out of the shield
What is the difference between materials used in aerospace manufacturing and materials in the general industry? What kind of properties do these materials have?
Ye Hongtao: Constantly improving the requirements for aeroengine performance indicators determines the development trend of its materials. Higher push-to-weight ratios, higher rotational speeds, and pre-turbine temperatures determine that the constituent materials should have lighter weight, higher strength, and higher temperature resistance. From the research and development of foreign aviation engines, the application trend of aviation launching China Metalworking Online Copyright Machine has the following characteristics: 1 Titanium alloy accounts for a larger proportion of all materials in the engine, titanium alloy and other metal structural materials. Compared, it has significant advantages such as high specific strength, good medium temperature performance and corrosion resistance. The specific gravity of titanium alloy is only about half of that of alloy steel, and the strength is much higher than that of aluminum. Steel and aluminum parts used extensively on early engines have been replaced by titanium alloys. Most of the low-temperature rotating parts are made of titanium alloy, and the steel machine that was originally used for cost considerations is also made of titanium alloy. 2 high-temperature alloys replace heat-resistant Chinese metal processing online copyright steel has become the main material for high-temperature components. Nickel-based and iron-based superalloys are basically used for the high-temperature components of the compressor, the combustion chamber components, the turbine components, the nozzles, and the like. In addition to conventional forged and cast superalloys, oriented crystalline superalloys, single crystal superalloys and powder metallurgy superalloys have also been used in a wider range. 3 applications such as composite materials. The outer casing machine and other parts began to use the lighter carbon fiber composite material instead of the original aluminum alloy or steel to reduce the weight of the whole machine to a greater extent.
Zhang Yufeng: Stainless steel, superalloy and aluminum-magnesium alloy are the main materials used in the manufacture of aerospace products, but high-temperature alloys (including Fe-based, Ni-based and Co-based) and titanium alloy materials used in some special parts. Processing is the biggest headache.
Superalloys and titanium alloys maintain high toughness and low thermal conductivity at high temperatures above 540 °C. They are called heat-resistant "super-strong alloys". These heat-resistant "super-strong alloys" can work long-term under high temperature oxidizing atmosphere or gas conditions, can increase service life and have some special properties, and are now widely used in aerospace, power station and steam turbine industries.
Due to the composition and texture characteristics of the heat-resistant "super-strong alloy", the cutting performance is poor. A comparison has been made in the industry. If the cutting performance of 45 steel is used as the benchmark 1, the relative processing property of the Ni-based superalloy is only 0.05 to 0.2; the titanium alloy is formed according to the carbon content (the carbon content is >0.2%). Hard carbides reduce cutting performance), and their relative processability is only 0.2 to 0.3.
The main reason for the poor cutting performance of heat-resistant "super-strong alloy" is the main factors of deformation resistance, processing temperature and work hardening.
Shield out of the "sword" out of the sheath
Since these advanced materials have emerged in the aerospace manufacturing industry, our related technicians have cracked these difficult-to-machine materials to serve our aerospace industry.
Yang Liming and He Fang, engineers of Shenyang Liming Aero Engine (Group) Co., Ltd., have unique insights into the processing of these materials.
He Fang: From the perspective of metal processing, according to the trend of the two engineers mentioned above, the proportion of difficult-to-machine materials represented by titanium alloys, high-temperature alloys, etc. is increasing, and the proportion of traditional steel, aluminum and other relatively easy-to-machine materials It is relatively reduced. This makes our personnel engaged in metalworking processes face even more serious challenges.
Compared with steel, aluminum and other materials, our experimental research on difficult-to-machine materials is much less. This is not only because the application of these materials is usually limited to aerospace and other professional fields, but more importantly, due to poor machinability and short tool life, the cost of cutting difficult to machine materials is much greater than that of ordinary materials. For many of the new aerospace engine materials that have emerged in recent years, the relevant cutting data is also lacking. This also affects the construction of related databases.
Fortunately, for the processing of some difficult-to-machine materials such as Ti6Al4V and Inconel718, which have been widely used in aerospace engines at home and abroad, in the past 20 years, China's aviation enterprises and research institutes have accumulated considerable processing experience and achieved Quite a lot of research results. Since the beginning of this century, the high-speed cutting test of difficult-to-machine materials jointly conducted by China Metalworking Online Co., Ltd. and Nanjing University of Aeronautics and Astronautics has used the solid carbide milling cutter to cut the milling speed of Ti6Al4V blade parts from the original 24m. /min is increased to 160m/min, and the speed of milling Inconnel718 alloy material using indexable ceramic inserts is more than 300m/min.
These research results provide useful reference for the processing of new titanium alloys and superalloy materials. The titanium alloy material used in the new engine is difficult to be Ti6Al4V in terms of machinability, but the processing law is similar. Inconel alloy processing experience is still very helpful in our research on casting, powder metallurgy, oriented crystallization and processing of single crystal superalloys.
Yang Jinfa: The advancement of cutting tools in the aerospace industry has driven the development of the aviation industry, and high-performance tools continue to meet the needs of new materials processing in the aerospace industry. Especially in the manufacture of engines, advanced tools such as carbide tools, ceramic tools, and CBN tools play an important role in the processing of difficult-to-machine materials.
For example, when we mill a thin-walled part, the material GH2132 is solid solution and aging, and the hardness is high. The material has a high cutting temperature; the work hardening tendency is large; the depth of the hardened layer can reach 0.04 mm during cutting, which has adverse effects on the cutting process. The material has high strength, large plasticity and toughness, large surface residual stress, easy to cause processing defects, and the performance of the surface layer of the part is lowered, which affects the surface quality of the part. In the cutting process, the cutting depth and the feed amount should be reasonably selected so that the cutting edge can be cut under the hardened layer, otherwise it will bring difficulties to the cutting and accelerate the tool wear. The diameter of the part is large, and the wall thickness is thin, so that the rigidity of the part is greatly reduced, resulting in an increase in cutting force, vibration occurs during processing, and the part is deformed, and the surface of the part is prone to oscillating ripple. Therefore, in the cutting test, we perform multiple layering processing according to the depth of the workpiece. The milling cutter selected according to the material characteristics of the part needs to have high hardness, wear resistance, thermal stability, excellent chemical stability and strong thermal conductivity and low friction factor. The tool geometry must be chosen reasonably. If the geometric angle of the milling cutter is unreasonable, it will cause severe deformation of the part. Therefore, we select different tool geometries to process such parts according to the manufacturing characteristics of domestic and foreign tool companies.
Another example is that when we drill TC4 material, the hardness is higher because the material is solution treated and aged. The material has a small cutting deformation coefficient, and the material itself is susceptible to strong chemical reaction with various gas impurities, resulting in an increase in the hardness and brittleness of the surface layer of the part. Due to the low thermal conductivity of the TC4 material, the thermal conductivity is poor, and the heat of cutting accumulates in a narrow area near the cutting edge, which accelerates tool wear. When the cutting temperature is high, under the action of the cutting force, the chip and the surface of the workpiece are bonded to the tool material, which causes a serious sticking phenomenon and affects the surface quality of the copyrighted parts. Drilling holes on TC4 materials requires the drill to have sufficient hardness, wear resistance and strong chip removal capability. According to the characteristics of this type of material, when selecting a drill bit, it is better to use a drill with a cooling method of internal cooling, which can effectively improve the cutting conditions. The apex angle of the drill bit is slightly larger, which not only improves the chip removal performance of the drill bit, but also facilitates the heat dissipation of the tool tip and improves the service life of the tool.
Bright "sword" metal processing
There are no two blades in the world that are exactly the same. Therefore, no matter what a good knife, as long as the manufacturer is different, their product quality and tool type have their own characteristics.
Regardless of how companies evaluate their products, end-user evaluations should be the most impartial and objective. In the end, the tools produced by domestically produced tool companies are excellent, or the foreign tool products are slightly better. We listened to the evaluations of the two engineers below.
Yang Jinfa: The advantages of imported tools are the dimensional accuracy and stability of the processing, long service life, high cutting efficiency, and good interchangeability of the tools and their accessories. The relative disadvantage is the high cost of imported tools and long lead times. Domestic tools have certain advantages in price. From the current situation, some domestic tools are used for imported material processing, and some imported tools are used for domestic material processing. The cutting performance of the machined tools is almost the same, and the price varies greatly. Under the premise of the financial crisis, aviation companies are paying more attention to cheaper and better quality domestically produced tools while purchasing more cost-effective tools.
For example, when I first saw the GH2132 cutting, we have done cutting experiments on two different tools at home and abroad. According to the final experimental results, we have come to the conclusion that some domestic milling cutters have cutting performance. The level of imported tools has been reached, and the processed parts meet the requirements of the aviation manufacturing industry, but the domestic copyright of the Chinese tool processing online is not stable enough. From the analysis of tool cost, the cost of domestic tools is about 1/3 of imported tools, which is very effective in reducing tool costs. We have also done the drilling experiment of the second material I mentioned earlier. The results show that the domestic tool is almost the same as the foreign tool in the service life. However, we should use the domestic tool when applying the domestic drill bit in the online processing of metal processing in China. The characteristics are continuously explored in terms of tool clamping, system stability and cutting parameter optimization. I think that a good domestic drill has the ability to replace the imported drill bit, but the price is equivalent to about 1/2 of the imported drill bit. The application of domestic drills not only ensures the quality of the parts but also greatly reduces the cost of the tools and achieves the intended purpose.
In short, the replacement of some imported tools by domestically produced tools meets the requirements of the scientific development concept, and the demand for localization of tools in the aviation manufacturing industry is strong, which is both an opportunity and a challenge for domestic tool companies. Some domestic tool companies have a lot of advanced sharpening equipment, and the sharpening of the tool is not much different from the imported tool. When processing certain materials, the cutting performance of domestically produced tools is comparable to that of imported tools, and some domestically produced tools have certain advantages in cost performance, which can completely replace imported tools.
Zhang Yufeng: After several years of work and research, I feel that there are two main differences between domestic CNC cutters and foreign CNC cutters: First, the scientific and technological content is low. At this stage, the carbide cutters are issued in China Metalworking Online. The country has occupied a dominant position in the type of tool, with a proportion of up to 70%. High-speed steel tools are shrinking at a rate of 1% to 2% per year, and the proportion has now fallen below 30%. At the same time, cemented carbide cutting tools have become the main tools required by processing enterprises in China. They are widely used in heavy industry such as automobile and parts production, mold manufacturing, aviation China metal processing, online aerospace, etc. Blindly and mass-produced high-speed steel knives and some low-grade standard knives, without considering the market saturation and enterprise needs, and finally giving high-value-added, high-tech content to the high-end tool market to foreign companies. . Second, the Chinese metal processing online copyright service is not in line with the international, multinational companies, such as Germany's Xiongke, Japan's Jiejie, Denmark's Unimog, Sweden's Seco and Sandvik Coromant, the United States Kenner and other tool manufacturers, In the long history of development, we have accumulated rich production experience, which determines that its service form is no longer a “single hammer saleâ€, but goes beyond the primary sales stage of only providing customers with tools, according to the customer’s production process. The problems encountered in the tool and the timely solution, this advanced form of integrating sales into the production process of the enterprise has become the usual sales method for foreign companies, which is why the products produced by well-known tool companies are expensive. In the city, some Chinese companies are one of the reasons why they are not able to win the favor of customers.
"Hero" who is ups and downs
No matter how good the sword is, the swordsman is also a scrap iron. Therefore, a good tool should have a good machine tool to support his reputation, and only "heroes" can match the "sword." Let's take a look at how our engineers view machine tool products at home and abroad.
Zhang Yufeng: The aerospace manufacturing industry is the most important component of the military industry. Its technical level and production capacity are a comprehensive reflection of the country's manufacturing strength and the modernization level of the national defense science and technology industry. It plays an important and irreplaceable role in the national economy and national defense modernization. Status and role. Due to the high or even demanding requirements of aerospace products for structural design, function and performance, service environment, product quality and reliability, large Chinese metal processing online copyright new materials and new structures are first in aerospace products. Applicable; defense needs and market competition require the development cycle and production cycle of aerospace China Metalworking Online Copyright products to be greatly shortened; in addition, the life cycle cost of the final product is required to be continuously reduced. Aerospace products put forward higher requirements for manufacturing technology, and advanced manufacturing technologies are widely used in aerospace manufacturing at home and abroad. CNC machine tools and equipment are an important component of advanced manufacturing technology and have become one of the key technologies in the manufacture of aerospace products.
Since the end of the 1990s, China has mastered the open architecture based on the general 32-bit industrial control machine, solved the conversion of the system structure, improved the reliability of the numerical control system, and the average trouble-free running time increased from 5000h to over 15 000h. Reach the international advanced level. China's low-end Chinese metal processing online copyright CNC machine tools have been widely used in aerospace product manufacturing, mainly for CNC lathes, vertical machining centers, CNC milling machines, CNC boring machines, CNC gear machines, CNC grinding machines, electric machining machines, CNC forming The machine tool has a good cost performance and competitiveness, and has been recognized by the manufacturing industry, basically meeting domestic demand.
Long-term dependence on foreign imports of a group of urgently needed high-end CNC machine tools developed abroad has achieved certain breakthroughs, but its accuracy needs to be improved to fully adapt to the manufacture of aerospace products. It represents CNC machine tools with five-axis linkage beam moving high-speed gantry milling machining center, five-axis linkage gantry machining center, five-axis linkage turning and milling center, five-axis linkage blade machining center, five-axis linkage horizontal machining center and other CNC machine tools.
As an aerospace manufacturing company, in addition to the test technology and price, it also selects the service quality of CNC machine tool manufacturers. Since the CNC machine tools between enterprises have a certain foundation in the past few years, whether they are technicians or operators, as a CNC machine tool manufacturer, a special service plan should be formulated according to the actual situation of each enterprise.
Gao Hong: In the existing CNC equipment of our company, about half of the service age is more than 10 years. The common phenomenon is that the numerical control system is aging, the hardware is facing elimination, the precision is lost, and the normal production is affected. It has reached the overhaul cycle and is in urgent need. Great modification, CNC system update.
At present, there are many manufacturers of CNC systems, such as Germany's Siemens, Japan's FANUC, France's NUM, Germany's Heidehan, etc., such as Wuhan Huazhong CNC, Beijing Aerospace CNC System Group, Shenyang High-grade CNC National Engineering Compared with the foreign digital control system of China Metal Processing, the research center and Guangzhou CNC Company have objectively improved the development of China's CNC system industry. The economical CNC system has formed a scale advantage, its function and performance. Continuous improvement, price and service advantages, the gap between reliability and foreign systems has also been significantly reduced, and with the full digital AC servo drive system and spindle servo drive system and other supporting capabilities, in the CNC milling machine, machining center and other mid-range CNC machine tools are available in batch applications. However, the performance, function, reliability and applicability of China's high-end CNC systems do have a big gap with the foreign metal processing online copyrights in China. The high-performance CNC system basically relies on imports, and the users have low recognition of the domestic brand market. Domestic enterprises have backward technological scale production technology, which affects the reliability and quality stability of products. Foreign brands still occupy more than 80% of the Chinese market. The domestic CNC system brand has a small share, and the market is completely monopolized by foreign countries. Especially for the high-end CNC machine tools urgently needed by the national defense industry, foreign countries still restrict the blockade of China in supporting high-end CNC systems. Therefore, the high-grade CNC system has become the main bottleneck restricting the development of China's high-end CNC machine tools. The core key components of domestic CNC machine tool equipment are Key factors that determine its performance, functionality, reliability, and cost.
Therefore, for the transformation of CNC lathes, milling machines and machining centers, the domestic CNC system can fully meet the functional requirements, and can greatly reduce the transformation cost, and at the same time promote the pace of domestic CNC products to brand and industrialization.
Looking to the future
The world is progressing and technology is developing. The aerospace industry is also developing rapidly, so only the "swords" and "heroes" of machine tools are constantly improving their capabilities to adapt to this constantly updated planet.
Where will our machine tools go? See what our engineers say?
Zhang Yufeng: With the development of aerospace manufacturing industry, the trend of small and medium batch production in the processing of aerospace products is increasing, which puts higher requirements on the flexibility and versatility of CNC machine tools, and requires the market to provide different processing requirements. And from the efficient, low-cost user-oriented control system, and greatly reduce the cost of maintaining and training the online copyright of China's metal processing, but also requires a new generation of CNC system with convenient network functions, to better adapt to the various production shop tasks And the paperless production organization and management mode of the order and the advancement of the DNC CNC networked system. In the past ten years, with the rapid development of computer technology, various levels of open CNC systems have emerged as the times require, and they are developing rapidly. Currently, they are advancing toward the standardization of all open architectures of China Metalworking Online. In terms of the current structural form, the numerical control system in the world today has a traditional numerical control system, an open CNC system with a "PC embedded NC" structure, an open CNC system with an "NC embedded PC" structure, a SOFT open CNC system, etc. Four types.
Throughout the development of CNC technology in China over the past few years, although we have achieved a lot of achievements, compared with the speed and level of development of foreign developed countries, the gap is still very large. It is mainly manifested in low technical content, low variety and unstable quality. Due to the poor competitiveness of domestic CNC systems, the current medium and high-end CNC system in China is basically monopolized by foreign products.
Through the analysis of the development of numerical control technology above, as an aerospace manufacturing enterprise, the development direction of CNC machine tools should focus on the realization of key functional components and CNC system industrialization, lay the foundation for the upgrade of CNC machine tools, and develop high-precision numerical control measuring instruments and numerical control. The tool is matched for medium and high-grade CNC machine tools.
In the aerospace manufacturing industry, the number of CNC machine tools is considerable, and a large number of foreign CNC machining centers and CNC electric machining equipment are introduced. High-precision and high-automatic machining machine tools have become the focus of equipment introduction for aerospace manufacturing enterprises. Improving the level of aerospace manufacturing and production capacity has played an important role, but the overall industry is not ideal for the use of equipment first. For example, the five-axis linkage of China Metalworking Online Co., Ltd. uses only three-axis linkage, and the CNC machining center is used as an ordinary three-axis milling machine. The main reason is the performance of CNC machine tools by Chinese metalworking operators. Understand the insufficiency, CNC machine tool training is not enough. Therefore, as a manufacturer of CNC machine tools, we should make detailed post-training plans according to the CNC machine tools we sell, such as maintenance, CAD/CAM application, and upgrade of CNC system. Only the service is in place, the equipment capacity is enough, and the company has received the effect. The company's CNC machine tools will be further promoted in the enterprise.
Yang Jinfa: The adoption of each new type of material in the aviation manufacturing industry will put forward new requirements for tool performance. Domestic tool companies only have to adapt to the needs of difficult processing materials and new material processing, and give full play to the resource advantages and human resources advantages of tool materials. In the tool management level, quality assurance technology and other aspects of rapid improvement, we can continue to promote the application of domestic tools in the aviation industry.
Gao Hong: The advancement of science and technology has brought about the rapid development of China's basic manufacturing industry, especially the application of computer technology in the field of numerical control technology. CNC products are increasingly developing in the direction of digitalization, networking and intelligence, based on PC. With its openness, low cost, high reliability, and abundant hardware and software resources, more CNC system manufacturers continue to develop toward the sixth generation of open, PC-based China Metalworking Online. In the future, the accuracy of CNC systems is getting higher and higher, the speed is getting faster and faster, the control functions are more and more humanized and intelligent, the functions are more and more powerful, the complexity is getting stronger and stronger, and on the contrary, the maintainability is getting weaker. . In today's transitional period, how to keep pace with the times, to develop the eyes of China Metal Processing Online Copyright, grasp the future development direction of CNC technology, break the inherent equipment maintenance mode, and study the characteristics of equipment maintenance in the future period is very important And necessary topics.
Due to the increasingly complex modern maintenance technology, our maintenance concept, maintenance ideas and means should also be updated. In view of the increasing proportion of CNC system software in the entire CNC machine tool, the CNC system software, data management and maintenance The method is worthy of our research and exploration of new topics. From the perspective of dialectical, the hardware and software of the CNC system are equivalent. The hardware provides the support environment for the operation of the software. The software is used to realize the function and process management and control. In the past, during the equipment maintenance process. We pay more attention to the repair and replacement of hardware, neglecting the summary and application of the maintenance methods of numerical control system data and related software, which weakens the role of software maintenance in equipment maintenance to a certain extent; with a scientific and development perspective Looking at the management and maintenance of CNC equipment in the future, if you can combine hardware repair and software maintenance, you will get twice the result with half the effort.
However, supporting these aerospace manufacturing giants at the show is advanced metalworking manufacturing technology and machine tool equipment. Today, the world aerospace manufacturing industry is not only a competition for manufacturing technology, but also a competition for machine tool companies. The various special materials involved in aerospace manufacturing are based on the absence of advanced machine tools, and there is no progress and development in the world aviation industry. So, what are the main materials used in aerospace manufacturing today? What is the difference between the characteristics of materials and the performance of other industries? What is the difference between tools and machine tools used in metal processing and general metal processing? To this end, we are fortunate to have invited first-line engineers specializing in metal cutting, equipment repair and material application research in aerospace manufacturing, in "Metal Processing" and China Metal Processing Online Theory "Sword".
Spear is not out of the shield
What is the difference between materials used in aerospace manufacturing and materials in the general industry? What kind of properties do these materials have?
Ye Hongtao: Constantly improving the requirements for aeroengine performance indicators determines the development trend of its materials. Higher push-to-weight ratios, higher rotational speeds, and pre-turbine temperatures determine that the constituent materials should have lighter weight, higher strength, and higher temperature resistance. From the research and development of foreign aviation engines, the application trend of aviation launching China Metalworking Online Copyright Machine has the following characteristics: 1 Titanium alloy accounts for a larger proportion of all materials in the engine, titanium alloy and other metal structural materials. Compared, it has significant advantages such as high specific strength, good medium temperature performance and corrosion resistance. The specific gravity of titanium alloy is only about half of that of alloy steel, and the strength is much higher than that of aluminum. Steel and aluminum parts used extensively on early engines have been replaced by titanium alloys. Most of the low-temperature rotating parts are made of titanium alloy, and the steel machine that was originally used for cost considerations is also made of titanium alloy. 2 high-temperature alloys replace heat-resistant Chinese metal processing online copyright steel has become the main material for high-temperature components. Nickel-based and iron-based superalloys are basically used for the high-temperature components of the compressor, the combustion chamber components, the turbine components, the nozzles, and the like. In addition to conventional forged and cast superalloys, oriented crystalline superalloys, single crystal superalloys and powder metallurgy superalloys have also been used in a wider range. 3 applications such as composite materials. The outer casing machine and other parts began to use the lighter carbon fiber composite material instead of the original aluminum alloy or steel to reduce the weight of the whole machine to a greater extent.
Zhang Yufeng: Stainless steel, superalloy and aluminum-magnesium alloy are the main materials used in the manufacture of aerospace products, but high-temperature alloys (including Fe-based, Ni-based and Co-based) and titanium alloy materials used in some special parts. Processing is the biggest headache.
Superalloys and titanium alloys maintain high toughness and low thermal conductivity at high temperatures above 540 °C. They are called heat-resistant "super-strong alloys". These heat-resistant "super-strong alloys" can work long-term under high temperature oxidizing atmosphere or gas conditions, can increase service life and have some special properties, and are now widely used in aerospace, power station and steam turbine industries.
Due to the composition and texture characteristics of the heat-resistant "super-strong alloy", the cutting performance is poor. A comparison has been made in the industry. If the cutting performance of 45 steel is used as the benchmark 1, the relative processing property of the Ni-based superalloy is only 0.05 to 0.2; the titanium alloy is formed according to the carbon content (the carbon content is >0.2%). Hard carbides reduce cutting performance), and their relative processability is only 0.2 to 0.3.
The main reason for the poor cutting performance of heat-resistant "super-strong alloy" is the main factors of deformation resistance, processing temperature and work hardening.
Shield out of the "sword" out of the sheath
Since these advanced materials have emerged in the aerospace manufacturing industry, our related technicians have cracked these difficult-to-machine materials to serve our aerospace industry.
Yang Liming and He Fang, engineers of Shenyang Liming Aero Engine (Group) Co., Ltd., have unique insights into the processing of these materials.
He Fang: From the perspective of metal processing, according to the trend of the two engineers mentioned above, the proportion of difficult-to-machine materials represented by titanium alloys, high-temperature alloys, etc. is increasing, and the proportion of traditional steel, aluminum and other relatively easy-to-machine materials It is relatively reduced. This makes our personnel engaged in metalworking processes face even more serious challenges.
Compared with steel, aluminum and other materials, our experimental research on difficult-to-machine materials is much less. This is not only because the application of these materials is usually limited to aerospace and other professional fields, but more importantly, due to poor machinability and short tool life, the cost of cutting difficult to machine materials is much greater than that of ordinary materials. For many of the new aerospace engine materials that have emerged in recent years, the relevant cutting data is also lacking. This also affects the construction of related databases.
Fortunately, for the processing of some difficult-to-machine materials such as Ti6Al4V and Inconel718, which have been widely used in aerospace engines at home and abroad, in the past 20 years, China's aviation enterprises and research institutes have accumulated considerable processing experience and achieved Quite a lot of research results. Since the beginning of this century, the high-speed cutting test of difficult-to-machine materials jointly conducted by China Metalworking Online Co., Ltd. and Nanjing University of Aeronautics and Astronautics has used the solid carbide milling cutter to cut the milling speed of Ti6Al4V blade parts from the original 24m. /min is increased to 160m/min, and the speed of milling Inconnel718 alloy material using indexable ceramic inserts is more than 300m/min.
These research results provide useful reference for the processing of new titanium alloys and superalloy materials. The titanium alloy material used in the new engine is difficult to be Ti6Al4V in terms of machinability, but the processing law is similar. Inconel alloy processing experience is still very helpful in our research on casting, powder metallurgy, oriented crystallization and processing of single crystal superalloys.
Yang Jinfa: The advancement of cutting tools in the aerospace industry has driven the development of the aviation industry, and high-performance tools continue to meet the needs of new materials processing in the aerospace industry. Especially in the manufacture of engines, advanced tools such as carbide tools, ceramic tools, and CBN tools play an important role in the processing of difficult-to-machine materials.
For example, when we mill a thin-walled part, the material GH2132 is solid solution and aging, and the hardness is high. The material has a high cutting temperature; the work hardening tendency is large; the depth of the hardened layer can reach 0.04 mm during cutting, which has adverse effects on the cutting process. The material has high strength, large plasticity and toughness, large surface residual stress, easy to cause processing defects, and the performance of the surface layer of the part is lowered, which affects the surface quality of the part. In the cutting process, the cutting depth and the feed amount should be reasonably selected so that the cutting edge can be cut under the hardened layer, otherwise it will bring difficulties to the cutting and accelerate the tool wear. The diameter of the part is large, and the wall thickness is thin, so that the rigidity of the part is greatly reduced, resulting in an increase in cutting force, vibration occurs during processing, and the part is deformed, and the surface of the part is prone to oscillating ripple. Therefore, in the cutting test, we perform multiple layering processing according to the depth of the workpiece. The milling cutter selected according to the material characteristics of the part needs to have high hardness, wear resistance, thermal stability, excellent chemical stability and strong thermal conductivity and low friction factor. The tool geometry must be chosen reasonably. If the geometric angle of the milling cutter is unreasonable, it will cause severe deformation of the part. Therefore, we select different tool geometries to process such parts according to the manufacturing characteristics of domestic and foreign tool companies.
Another example is that when we drill TC4 material, the hardness is higher because the material is solution treated and aged. The material has a small cutting deformation coefficient, and the material itself is susceptible to strong chemical reaction with various gas impurities, resulting in an increase in the hardness and brittleness of the surface layer of the part. Due to the low thermal conductivity of the TC4 material, the thermal conductivity is poor, and the heat of cutting accumulates in a narrow area near the cutting edge, which accelerates tool wear. When the cutting temperature is high, under the action of the cutting force, the chip and the surface of the workpiece are bonded to the tool material, which causes a serious sticking phenomenon and affects the surface quality of the copyrighted parts. Drilling holes on TC4 materials requires the drill to have sufficient hardness, wear resistance and strong chip removal capability. According to the characteristics of this type of material, when selecting a drill bit, it is better to use a drill with a cooling method of internal cooling, which can effectively improve the cutting conditions. The apex angle of the drill bit is slightly larger, which not only improves the chip removal performance of the drill bit, but also facilitates the heat dissipation of the tool tip and improves the service life of the tool.
Bright "sword" metal processing
There are no two blades in the world that are exactly the same. Therefore, no matter what a good knife, as long as the manufacturer is different, their product quality and tool type have their own characteristics.
Regardless of how companies evaluate their products, end-user evaluations should be the most impartial and objective. In the end, the tools produced by domestically produced tool companies are excellent, or the foreign tool products are slightly better. We listened to the evaluations of the two engineers below.
Yang Jinfa: The advantages of imported tools are the dimensional accuracy and stability of the processing, long service life, high cutting efficiency, and good interchangeability of the tools and their accessories. The relative disadvantage is the high cost of imported tools and long lead times. Domestic tools have certain advantages in price. From the current situation, some domestic tools are used for imported material processing, and some imported tools are used for domestic material processing. The cutting performance of the machined tools is almost the same, and the price varies greatly. Under the premise of the financial crisis, aviation companies are paying more attention to cheaper and better quality domestically produced tools while purchasing more cost-effective tools.
For example, when I first saw the GH2132 cutting, we have done cutting experiments on two different tools at home and abroad. According to the final experimental results, we have come to the conclusion that some domestic milling cutters have cutting performance. The level of imported tools has been reached, and the processed parts meet the requirements of the aviation manufacturing industry, but the domestic copyright of the Chinese tool processing online is not stable enough. From the analysis of tool cost, the cost of domestic tools is about 1/3 of imported tools, which is very effective in reducing tool costs. We have also done the drilling experiment of the second material I mentioned earlier. The results show that the domestic tool is almost the same as the foreign tool in the service life. However, we should use the domestic tool when applying the domestic drill bit in the online processing of metal processing in China. The characteristics are continuously explored in terms of tool clamping, system stability and cutting parameter optimization. I think that a good domestic drill has the ability to replace the imported drill bit, but the price is equivalent to about 1/2 of the imported drill bit. The application of domestic drills not only ensures the quality of the parts but also greatly reduces the cost of the tools and achieves the intended purpose.
In short, the replacement of some imported tools by domestically produced tools meets the requirements of the scientific development concept, and the demand for localization of tools in the aviation manufacturing industry is strong, which is both an opportunity and a challenge for domestic tool companies. Some domestic tool companies have a lot of advanced sharpening equipment, and the sharpening of the tool is not much different from the imported tool. When processing certain materials, the cutting performance of domestically produced tools is comparable to that of imported tools, and some domestically produced tools have certain advantages in cost performance, which can completely replace imported tools.
Zhang Yufeng: After several years of work and research, I feel that there are two main differences between domestic CNC cutters and foreign CNC cutters: First, the scientific and technological content is low. At this stage, the carbide cutters are issued in China Metalworking Online. The country has occupied a dominant position in the type of tool, with a proportion of up to 70%. High-speed steel tools are shrinking at a rate of 1% to 2% per year, and the proportion has now fallen below 30%. At the same time, cemented carbide cutting tools have become the main tools required by processing enterprises in China. They are widely used in heavy industry such as automobile and parts production, mold manufacturing, aviation China metal processing, online aerospace, etc. Blindly and mass-produced high-speed steel knives and some low-grade standard knives, without considering the market saturation and enterprise needs, and finally giving high-value-added, high-tech content to the high-end tool market to foreign companies. . Second, the Chinese metal processing online copyright service is not in line with the international, multinational companies, such as Germany's Xiongke, Japan's Jiejie, Denmark's Unimog, Sweden's Seco and Sandvik Coromant, the United States Kenner and other tool manufacturers, In the long history of development, we have accumulated rich production experience, which determines that its service form is no longer a “single hammer saleâ€, but goes beyond the primary sales stage of only providing customers with tools, according to the customer’s production process. The problems encountered in the tool and the timely solution, this advanced form of integrating sales into the production process of the enterprise has become the usual sales method for foreign companies, which is why the products produced by well-known tool companies are expensive. In the city, some Chinese companies are one of the reasons why they are not able to win the favor of customers.
"Hero" who is ups and downs
No matter how good the sword is, the swordsman is also a scrap iron. Therefore, a good tool should have a good machine tool to support his reputation, and only "heroes" can match the "sword." Let's take a look at how our engineers view machine tool products at home and abroad.
Zhang Yufeng: The aerospace manufacturing industry is the most important component of the military industry. Its technical level and production capacity are a comprehensive reflection of the country's manufacturing strength and the modernization level of the national defense science and technology industry. It plays an important and irreplaceable role in the national economy and national defense modernization. Status and role. Due to the high or even demanding requirements of aerospace products for structural design, function and performance, service environment, product quality and reliability, large Chinese metal processing online copyright new materials and new structures are first in aerospace products. Applicable; defense needs and market competition require the development cycle and production cycle of aerospace China Metalworking Online Copyright products to be greatly shortened; in addition, the life cycle cost of the final product is required to be continuously reduced. Aerospace products put forward higher requirements for manufacturing technology, and advanced manufacturing technologies are widely used in aerospace manufacturing at home and abroad. CNC machine tools and equipment are an important component of advanced manufacturing technology and have become one of the key technologies in the manufacture of aerospace products.
Since the end of the 1990s, China has mastered the open architecture based on the general 32-bit industrial control machine, solved the conversion of the system structure, improved the reliability of the numerical control system, and the average trouble-free running time increased from 5000h to over 15 000h. Reach the international advanced level. China's low-end Chinese metal processing online copyright CNC machine tools have been widely used in aerospace product manufacturing, mainly for CNC lathes, vertical machining centers, CNC milling machines, CNC boring machines, CNC gear machines, CNC grinding machines, electric machining machines, CNC forming The machine tool has a good cost performance and competitiveness, and has been recognized by the manufacturing industry, basically meeting domestic demand.
Long-term dependence on foreign imports of a group of urgently needed high-end CNC machine tools developed abroad has achieved certain breakthroughs, but its accuracy needs to be improved to fully adapt to the manufacture of aerospace products. It represents CNC machine tools with five-axis linkage beam moving high-speed gantry milling machining center, five-axis linkage gantry machining center, five-axis linkage turning and milling center, five-axis linkage blade machining center, five-axis linkage horizontal machining center and other CNC machine tools.
As an aerospace manufacturing company, in addition to the test technology and price, it also selects the service quality of CNC machine tool manufacturers. Since the CNC machine tools between enterprises have a certain foundation in the past few years, whether they are technicians or operators, as a CNC machine tool manufacturer, a special service plan should be formulated according to the actual situation of each enterprise.
Gao Hong: In the existing CNC equipment of our company, about half of the service age is more than 10 years. The common phenomenon is that the numerical control system is aging, the hardware is facing elimination, the precision is lost, and the normal production is affected. It has reached the overhaul cycle and is in urgent need. Great modification, CNC system update.
At present, there are many manufacturers of CNC systems, such as Germany's Siemens, Japan's FANUC, France's NUM, Germany's Heidehan, etc., such as Wuhan Huazhong CNC, Beijing Aerospace CNC System Group, Shenyang High-grade CNC National Engineering Compared with the foreign digital control system of China Metal Processing, the research center and Guangzhou CNC Company have objectively improved the development of China's CNC system industry. The economical CNC system has formed a scale advantage, its function and performance. Continuous improvement, price and service advantages, the gap between reliability and foreign systems has also been significantly reduced, and with the full digital AC servo drive system and spindle servo drive system and other supporting capabilities, in the CNC milling machine, machining center and other mid-range CNC machine tools are available in batch applications. However, the performance, function, reliability and applicability of China's high-end CNC systems do have a big gap with the foreign metal processing online copyrights in China. The high-performance CNC system basically relies on imports, and the users have low recognition of the domestic brand market. Domestic enterprises have backward technological scale production technology, which affects the reliability and quality stability of products. Foreign brands still occupy more than 80% of the Chinese market. The domestic CNC system brand has a small share, and the market is completely monopolized by foreign countries. Especially for the high-end CNC machine tools urgently needed by the national defense industry, foreign countries still restrict the blockade of China in supporting high-end CNC systems. Therefore, the high-grade CNC system has become the main bottleneck restricting the development of China's high-end CNC machine tools. The core key components of domestic CNC machine tool equipment are Key factors that determine its performance, functionality, reliability, and cost.
Therefore, for the transformation of CNC lathes, milling machines and machining centers, the domestic CNC system can fully meet the functional requirements, and can greatly reduce the transformation cost, and at the same time promote the pace of domestic CNC products to brand and industrialization.
Looking to the future
The world is progressing and technology is developing. The aerospace industry is also developing rapidly, so only the "swords" and "heroes" of machine tools are constantly improving their capabilities to adapt to this constantly updated planet.
Where will our machine tools go? See what our engineers say?
Zhang Yufeng: With the development of aerospace manufacturing industry, the trend of small and medium batch production in the processing of aerospace products is increasing, which puts higher requirements on the flexibility and versatility of CNC machine tools, and requires the market to provide different processing requirements. And from the efficient, low-cost user-oriented control system, and greatly reduce the cost of maintaining and training the online copyright of China's metal processing, but also requires a new generation of CNC system with convenient network functions, to better adapt to the various production shop tasks And the paperless production organization and management mode of the order and the advancement of the DNC CNC networked system. In the past ten years, with the rapid development of computer technology, various levels of open CNC systems have emerged as the times require, and they are developing rapidly. Currently, they are advancing toward the standardization of all open architectures of China Metalworking Online. In terms of the current structural form, the numerical control system in the world today has a traditional numerical control system, an open CNC system with a "PC embedded NC" structure, an open CNC system with an "NC embedded PC" structure, a SOFT open CNC system, etc. Four types.
Throughout the development of CNC technology in China over the past few years, although we have achieved a lot of achievements, compared with the speed and level of development of foreign developed countries, the gap is still very large. It is mainly manifested in low technical content, low variety and unstable quality. Due to the poor competitiveness of domestic CNC systems, the current medium and high-end CNC system in China is basically monopolized by foreign products.
Through the analysis of the development of numerical control technology above, as an aerospace manufacturing enterprise, the development direction of CNC machine tools should focus on the realization of key functional components and CNC system industrialization, lay the foundation for the upgrade of CNC machine tools, and develop high-precision numerical control measuring instruments and numerical control. The tool is matched for medium and high-grade CNC machine tools.
In the aerospace manufacturing industry, the number of CNC machine tools is considerable, and a large number of foreign CNC machining centers and CNC electric machining equipment are introduced. High-precision and high-automatic machining machine tools have become the focus of equipment introduction for aerospace manufacturing enterprises. Improving the level of aerospace manufacturing and production capacity has played an important role, but the overall industry is not ideal for the use of equipment first. For example, the five-axis linkage of China Metalworking Online Co., Ltd. uses only three-axis linkage, and the CNC machining center is used as an ordinary three-axis milling machine. The main reason is the performance of CNC machine tools by Chinese metalworking operators. Understand the insufficiency, CNC machine tool training is not enough. Therefore, as a manufacturer of CNC machine tools, we should make detailed post-training plans according to the CNC machine tools we sell, such as maintenance, CAD/CAM application, and upgrade of CNC system. Only the service is in place, the equipment capacity is enough, and the company has received the effect. The company's CNC machine tools will be further promoted in the enterprise.
Yang Jinfa: The adoption of each new type of material in the aviation manufacturing industry will put forward new requirements for tool performance. Domestic tool companies only have to adapt to the needs of difficult processing materials and new material processing, and give full play to the resource advantages and human resources advantages of tool materials. In the tool management level, quality assurance technology and other aspects of rapid improvement, we can continue to promote the application of domestic tools in the aviation industry.
Gao Hong: The advancement of science and technology has brought about the rapid development of China's basic manufacturing industry, especially the application of computer technology in the field of numerical control technology. CNC products are increasingly developing in the direction of digitalization, networking and intelligence, based on PC. With its openness, low cost, high reliability, and abundant hardware and software resources, more CNC system manufacturers continue to develop toward the sixth generation of open, PC-based China Metalworking Online. In the future, the accuracy of CNC systems is getting higher and higher, the speed is getting faster and faster, the control functions are more and more humanized and intelligent, the functions are more and more powerful, the complexity is getting stronger and stronger, and on the contrary, the maintainability is getting weaker. . In today's transitional period, how to keep pace with the times, to develop the eyes of China Metal Processing Online Copyright, grasp the future development direction of CNC technology, break the inherent equipment maintenance mode, and study the characteristics of equipment maintenance in the future period is very important And necessary topics.
Due to the increasingly complex modern maintenance technology, our maintenance concept, maintenance ideas and means should also be updated. In view of the increasing proportion of CNC system software in the entire CNC machine tool, the CNC system software, data management and maintenance The method is worthy of our research and exploration of new topics. From the perspective of dialectical, the hardware and software of the CNC system are equivalent. The hardware provides the support environment for the operation of the software. The software is used to realize the function and process management and control. In the past, during the equipment maintenance process. We pay more attention to the repair and replacement of hardware, neglecting the summary and application of the maintenance methods of numerical control system data and related software, which weakens the role of software maintenance in equipment maintenance to a certain extent; with a scientific and development perspective Looking at the management and maintenance of CNC equipment in the future, if you can combine hardware repair and software maintenance, you will get twice the result with half the effort.
Our range of fiber optic end fittings combine classic styling with modern functionality, which is for decorative and functional applications.
Like all our end fittings, no electricity or heat is output from the fitting, so they are safe for use in wet or humid areas and specific models are suitable for use in high-traffic walk over areas.
If you wanna buy it, please contact with us.
End Fittings,Crystal Fittings,Fiber Optic Lighting Fixtures,Light Fittings
Jiangxi Daishing POF Co.,Ltd , https://www.jxopticfibrelight.com