Core Tip: Today, the development of domestic aerospace tools similar to other industries , if there are existing tools on the market can not solve the processing problems , especially in the field of aerospace products encountered in the processing of titanium alloy , aluminum Magnesium alloy and other difficult to process materials and composite materials processing problems , the need for tool suppliers and users in close cooperation , through the joint development , try to develop a special tool . At the same time , tool manufacturers in the product-oriented market before , are a lot of experiments , try to ensure that users meet the processing needs of the various processes.
1. Tool types for typical parts of aerospace manufacturing
Aerospace components not only use a lot of new structures , new technologies and new materials , but also complex parts configuration , poor rigidity , these factors to make the engine and other parts with the mechanical processing must use a large number of high-performance standard tools and special tools for processing.
At present , the engine disk parts , shaft parts , casing parts processing outsourcing of high-performance carbide standard tool and carbide non-standard tool ratio . Typical small and medium-sized components , leaf parts , such as the standard tool-based . In the actual processing of the choice of the main tool to consider the following factors : the workpiece material , the workpiece shape , processing requirements , processing machine tools , system rigidity , surface quality and technical requirements . Take turbine casing parts as an example , from the workpiece material analysis , deformation of high temperature alloys , casting high temperature alloys and other difficult to use a large number of materials . These difficult to process materials , small thermal conductivity , than the strength , high cutting temperature , easy to produce hardening . Cutting tool wears fast , tool life is short , tool consumption , and therefore must be a reasonable choice of tool geometry angle . From the workpiece structure point of view , the wall is thin , poor rigidity , difficult to process.
When machining parts raised parts , the tool system is easy to interfere with parts and fixtures . Therefore , the tool path must be optimized , such as milling milling instead of side milling , empty travel fast knife , optimize the position of the knife , the use of spiral interpolation and other means of milling . From the choice of machine tools , the turbine casing needs to be processed on a high-power machining center . From the processing process analysis , the casing needs to be rough , semi-finishing , finishing . In order to save the tool costs , in the manufacture of such parts , rough processing can be used high-performance ceramic cutter , semi-finishing and finishing using standard carbide cutting tools and non-standard high-performance special tool , which can significantly improve production efficiency The From the processing economy , the tool configuration program needs to be improved , as far as possible using the latest tool manufacturers R & D products.
2. Tool materials commonly used in aerospace manufacturing
With the aerospace industry , such as titanium alloy , high temperature alloys and other difficult to use a wide range of materials , how to correctly choose , the rational use of cutting tools for high-quality cutting has become a very important industry topics . With the workpiece materials and tool materials , structures and other mutual promotion , aerospace manufacturing industry to continue to develop , it can be said that the continuous development of the tool is the aerospace manufacturing industry continue to develop the driving force.
At present , the aerospace industry widely used tool materials are the following categories : tool steel (carbon tool steel , alloy tool steel , high speed steel ) , carbide , ceramic and superHeated tool materials . Among them , the largest proportion of carbide cutting tools , aircraft manufacturing is the leading tool , a wide range of applications . Compared with the cemented carbide , the ceramic material has higher hardness , hot hardness and abrasion resistance , and the chemical stability , oxidation resistance are better than the cemented carbide , therefore , the ceramic tool has become the development of the aviation industry tool A mainstream.
In the aerospace materials processing process , the groove processing and hole processing is difficult to process . Like the engine disk parts , shaft parts , casing parts processing tool processing requirements are very high , therefore , in such parts processing high-performance carbide standard tool and carbide non-standard tool use is very large The In the actual processing of the choice of the tool should consider the following factors : the workpiece material , the workpiece shape , processing requirements , processing machine tools , system rigidity , surface quality and technical requirements.
Take the turbine casing parts as an example , from the workpiece material analysis , deformation of high-temperature alloys , casting high-temperature alloys and other difficult to use a large number of materials , these difficult materials , thermal conductivity coefficient is small , high strength , high cutting temperature , easy to produce hardening , Tool wear fast , tool life is short , tool consumption , and therefore must be a reasonable choice of tool geometry.
From the point of view of the workpiece structure , the tool system is easy to interfere with the parts and fixtures when the wall is thin , the rigidity is poor , it is difficult to process and the parts of the parts are machined . Therefore , the tool path must be optimized such as milling milling instead of side milling and empty stroke Fast knife , optimize the position of the knife , the use of spiral interpolation , etc . milling.
From the processing process analysis , the casing needs to be rough , semi-finishing , finishing , in order to save the tool costs , in the manufacture of such parts , rough processing can be used high-performance ceramic cutter , semi-finishing and finishing The use of standard carbide cutting tools and non-standard high-performance special tools , which can significantly to improve production efficiency.
From the processing economy , the tool configuration program needs to be improved , as far as possible using the latest tool manufacturers R & D products . In the aviation manufacturing industry , the proportion of carbide cutting tools is the largest . Carbide tool for the aviation manufacturing is the leading tool , the scope of application is quite wide , in the NC tool material dominated . Carbide has become the main tool material , so that the cutting process to achieve the transition to the carbide age , due to different grades of carbide characteristics of different characteristics , and therefore its scope of application is also different . Carbide can be used not only to manufacture a variety of machines can be translatable tool , and can create a whole type of end mills , reamers , taps and drill bits . Carbide cutting tools is divided into ordinary hard alloy , coated carbide , ultrafine particles of cemented carbide , carbon (nitrogen ) titanium-based cemented carbide.
YT-type cemented carbide with YG class and YW class most of the excellent performance in the aerospace manufacturing industry is more widely used . Coated carbide has a higher hardness than the matrix , wear resistance , heat resistance , widely used . Ultrafine particles Carbide can be used in a wide range of intermittent cutting . Carbon (nitrogen ) titanium-based cemented carbide is mainly used for the continuous surface finishing and semi-finishing of steel parts.
At present , China's ceramic tool application is still in its infancy , the actual application of the development of slower . Ceramic cutting tools is mainly used for hard alloy cutting tools difficult to cut the workpiece rough . Aerospace manufacturing industry to promote the use of ceramic tools for a long time , in the ceramic tool geometric parameters , cutting the amount of use and technology need to accumulate experience . Ceramic materials Compared with cemented carbide , ceramic materials have higher hardness , heat and abrasion resistance . Ceramic tool chemical stability , antioxidant capacity are better than carbide , very suitable for dry continuous high-speed cutting high-temperature alloys , hardened just , bearing steel , high strength steel and other difficult to process materials . Aero engines in the application of many high-temperature alloys , shaft parts more , it is the ceramic tool to play its advantages . To achieve efficient processing , to replace some of the ceramic cutting tool carbide tool is completely feasible . Ceramic tool is not a universal tool , only the correct use in order to give full play to its superiority.
In view of the characteristics of ceramic cutting tools , the selection must pay attention to three aspects : ① to choose a good system rigidity , can effectively prevent the damage to the tool vibration , improve tool life . ② to prevent the impact of parts on the tool . For high hardness and irregular shape of the rough , should be cut and cut out at the first chamfering and then cutting . ③ to optimize the geometric parameters of the tool , the ceramic tool often used zero angle or negative front angle cutting . We have to fully grasp the performance of the workpiece material , based on the appropriate measures to make cutting to achieve high quality , high efficiency , low cost.
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