A large number of cemented carbide tools and ceramic tools are needed for parts processing in aerospace industry.
With the wide application of difficult-to-machine materials such as titanium alloy and high-temperature alloy in aerospace industry, how to correctly select and reasonably use tools for efficient and high-quality cutting has become a very important industrial topic. With the mutual promotion of workpiece materials, tool materials and structures, the aerospace manufacturing industry is developing continuously. It can be said that the continuous development of tools is the driving force for the continuous development of aerospace manufacturing.
At present, the tool materials widely used in aviation manufacturing mainly include the following categories: tool steel (carbon tool steel, alloy tool steel, high speed steel), cemented carbide, ceramics, and superhard tool materials. Among them, cemented carbide tools account for the largest proportion, which is the leading tool in aviation manufacturing industry and has a wide range of applications. Compared with cemented carbide, ceramic materials have higher hardness, thermal hardness and wear resistance, and their chemical stability and oxidation resistance are also better than cemented carbide. Therefore, ceramic tools have become the mainstream of tool development in aerospace industry.
"In the process of aerospace materials processing, groove processing and hole processing are both processing difficulties. The machining of engine disc parts, shaft parts and box parts requires very high machining tools. Therefore, high-performance cemented carbide standard tools and cemented carbide non-standard tools are used in the processing of such parts. " Bright Lo, Secretary-General of International Mould and Hardware & Plastics Suppliers Association and CEO of Golden Mould Tool Network, believes that the following factors should be considered in the selection of tools in actual machining: workpiece material, workpiece shape, machining requirements, machining machine tools, system rigidity, surface quality and technical requirements.
Taking turbine box parts as an example, it is found from the analysis of workpiece materials that deformed superalloys, cast superalloys and other difficult-to-machine materials are widely used. These difficult-to-machine materials have low thermal conductivity, high specific strength, high cutting temperature, easy work hardening, fast tool wear, short tool life and high tool consumption, so it is necessary to choose a reasonable tool geometry angle. From the perspective of workpiece structure, the wall is thin, the rigidity is poor, and the machining is difficult. When machining the convex part of the part, the tool system is easy to interfere with the part and fixture. Therefore, it is necessary to optimize the tool path, such as plug milling instead of side milling, fast feed in idle stroke, optimizing the position of lifting tool, spiral interpolation milling and so on. From the analysis of processing technology, the casing needs rough machining, semi-finish machining and finish machining. In order to save tool cost, high-performance ceramic milling cutter can be used in rough machining, and standard cemented carbide cutter and non-elevation special cutter can be used in semi-finishing and finishing, which can significantly improve production efficiency. From the aspect of machining economy, the tool configuration scheme needs to be improved continuously, and the latest products developed by tool manufacturers should be adopted as far as possible. Bright Lo suggested that Walter's WSM35 and WSP45 blades should be preferred when machining titanium alloys, superalloys and other workpieces. When the cutting depth is small, the cutting speed of these two blades can reach 70~ 150m/min. When machining workpieces with difficult-to-cut materials, two kinds of blades with coated material grade CP200 and uncoated material grade 890 will be given priority. These two kinds of blades are two kinds of high-hardness ultra-fine particle material-grade tools for high-temperature alloy finishing and titanium alloy processing, and also have good effects on stainless steel finishing.
In addition, imported brands such as Kenner, sandvik Coleman and iscar should be used to process refractories such as superalloys, titanium alloys and FRP composites.
At present, the development of domestic space tools is similar to other industries. If there are processing problems that can't be solved by the existing tools in the market, especially the processing problems of difficult-to-process materials and composite materials such as titanium alloy and aluminum-magnesium alloy encountered in the processing of high-tech products in the aerospace field, it is necessary for tool suppliers and users to cooperate closely to jointly develop and try to cut special tools. At the same time, tool manufacturers have gone through a lot of experiments and trial cuts before their products are put on the market to ensure that they can meet the various needs of users in the processing process.
Yang Wei, executive deputy secretary-general of China Aerospace Tools Association, believes that the tools that domestic tool companies can provide are mostly special tools according to the actual needs of users, and the technical content and product quality are not very high. The general tools on the market are incomplete and the quality is not high, and users still mainly use imported tools. Internationally renowned brands, such as Mountain Vic Cola, Iscar, Kenner, Secco, OSC, etc., have offices in big cities in China, which makes it very convenient to buy knives. Good after-sales service and product quality guarantee also make their competitive advantages superior to domestic enterprises. In such a competitive environment, China's space tool industry should give full play to its independent innovation ability and realize the localization of tools for application-oriented enterprises.
Bright Lo, Secretary-General of the International Mould and Hardware & Plastic Industry Suppliers Association, said that tool suppliers should know the real needs of users in detail and provide the products that users need most according to their actual needs. Tool suppliers should also provide technical guidance, provide detailed information of tools, such as what kind of tools are suitable for machining workpieces of what materials, and give the best cutting parameters of tools. Specifically, users hope that engineers sent by tool suppliers should not only be familiar with tools, material technology and development trends at home and abroad, but also be familiar with metal cutting technology and processing technology, the selection and application of all kinds of general-purpose tools and CNC tools, and be familiar with all kinds of CNC machine tools, and be able to independently compile processing technology and tool configuration schemes, so that users can get in touch with the most advanced tool technology in the world faster, and at the same time get better cost-effective tool products and quality after-sales service.
"Tool suppliers should constantly understand the needs of users, not only provide users with high-quality tools, but also provide users with feasible tool solutions, hold regular training, and convey advanced cutting technology and high-end cutting concepts to users' technicians." Bright Lo pointed out that the cutting technology of aerospace enterprises can be improved by effective comprehensive tool technical support. In this way, tool manufacturers can promote their advanced tools, meet the needs of cutting technology progress in aerospace industry, and form a good atmosphere of win-win for aviation manufacturing users and tool suppliers.