Application of CNC tool technology in aviation field

Today, with the continuous development of new aviation materials, there are an increasing number of difficult-to-machine materials such as high-strength steel, high-temperature alloys, titanium alloys, and composite materials. This plays an important role in promoting and promoting the development of CNC tool technology. In the development process of CNC high-speed cutting technology, the key position of cutting tools and cutting tool technology has become increasingly apparent.
The cutting heat and tool wear generated during CNC high-speed cutting are much higher than those during ordinary speed cutting. Therefore, the tool materials used in CNC high-speed cutting are very different from those used in ordinary speed cutting. The tool materials There are higher requirements, mainly including:

•High hardness, strength and wear resistance;

•High toughness and strong impact resistance;

•High thermal hardness and chemical stability;

•Strong thermal shock resistance.

Many new tool materials have emerged, but it is difficult to find tool materials that meet the above requirements at the same time. Therefore, the technology of cutting tools coated with high thermal hardness and wear resistance coatings on tool material substrates with relatively good impact toughness has developed rapidly. In addition, high-hardness materials such as CBN and diamond can also be sintered on a matrix of cemented carbide or ceramic materials with good impact resistance and toughness to form a CNC high-speed machining tool with excellent comprehensive cutting performance.
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With the increasing application of difficult-to-machine materials such as high-strength steel, high-temperature alloys, titanium alloys and composite materials in the aviation field, modern CNC tool materials can no longer be limited to the currently widely used high-speed steel and ordinary carbide, and should be based on different requirements. Processing materials, and select tool materials considering tool service life and processing quality. The following is a selection of CNC tool materials according to the classification of materials commonly used in domestic aviation manufacturing:

(1) Aluminum alloy: Aluminum alloy is most commonly used in the aviation field. Commonly used CNC tool materials include aluminum high-speed steel, K10 and K20 series of cemented carbides.

(2) Ordinary steel: For CNC cutting of ordinary steel, cobalt high-speed steel M42, cemented carbide and cermet are mainly used as tool materials in the domestic aviation manufacturing industry.

(3) High-strength steel and high-temperature alloys: In the field of aviation manufacturing, high-strength steel and high-temperature alloys account for an increasing proportion of materials. The tools used to process such parts mainly use high-strength, high-toughness and high-wear resistance. It is processed by cemented carbide materials and cermet materials that combine a durable ultra-fine grained alloy matrix and a TiAlN coating.

(4) Titanium alloy: Titanium alloy has high strength and high impact toughness. Its work hardening phenomenon is very serious. During cutting, the temperature is high and the tool wear is serious. When processing titanium alloy materials, cobalt high-speed steel M42 and Zhuzhou diamond cutting are often used. KMG405 and other series of carbide-coated tool materials produced by Tool Co., Ltd.

(5) Composite materials: Composite materials have been widely used in the aviation field, and their usage is growing rapidly. PCD-coated carbide and ceramics are mainly used as tool materials for processing such materials.
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(1) CNC high-speed cutting requirements for tool geometric parameters. In addition to the selection of tool materials, the correct selection of the geometric parameters of the cutting edge of the tool and the chip breaking method of the tool have a great impact on the efficiency of CNC high-speed cutting, the quality of the machined surface, the tool life and the generation of cutting heat. This is CNC An important factor in high-speed tool technology. The geometric parameter selection of the tool cutting edge should be considered from the following aspects:

•Appropriate tool relief angle and reasonable feed speed can produce sufficient chip thickness to take away heat and avoid cutting hardening.

•The rake angle of the cutting edge is an important parameter that affects the cutting load of the tool and should be selected reasonably.

•The cutting load is related to the feed per cutting edge of the tool. For multi-piece insert tools, the cutting load acts on each insert; for solid tools, the cutting load acts on each tooth. Therefore, the feed should be chosen between a reasonable value.


Generally speaking, the geometric angles of CNC high-speed tools mostly correspond to traditional tools. Choosing reasonable tool parameters, in addition to maintaining sharp cutting edges and sufficient strength, is also an important purpose to form chips of sufficient thickness so that the chips can become heat sinks for the cutting process. The higher the cutting speed, the more heat is generated. Therefore, in the CNC high-speed cutting process, the key issue is to find ways to transfer the cutting heat to the chips as much as possible, and to use the high-speed cutting chips to quickly carry the cutting heat away. Walk.

(2) Correct selection of tool materials and cutting parameters based on the workpiece material and processing procedures is an important link to ensure that CNC high-speed cutting can achieve the expected results. At present, CNC high-speed cutting parameters cannot be selected through relevant cutting manuals like ordinary cutting. CNC high-speed machining does not yet have a complete process parameter table and CNC high-speed cutting database. There is also no specific formula to determine the best value for each tool. The best combination of cutting parameters. In actual production, the optimal cutting speed and feed speed must be determined through experiments based on factors such as the materials being processed and process characteristics.
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(1) Inlaid tool with high connection strength. In CNC high-speed cutting, coating, laminated tool technology and embedded tools are widely used. For embedded tools, if the blade embedded in the cutter body does not have sufficient connection strength, it will be separated from the cutter body under the action of a large centrifugal force. Tools with a rotation speed of more than 10,000r/min have this risk. Therefore, it is not safe to use only one clamping screw to hold down the blade at high rotational speeds. The embedded tools used in high-speed cutting are different from ordinary tools. The insert must be safely embedded in the cutter body, that is, tightly embedded in the slot of the cutter body, and the insert must be fastened to the cutter body with screws in a direction perpendicular to the centrifugal force. .

(2) The connection method between the tool and the tool holder. The requirements for tool holders and tool chucks used in CNC high-speed cutting are: high clamping accuracy; large transmission torque; good structural symmetry, which is conducive to the dynamic balance of the tool; small overall size, but the overhang of the tool should be appropriately increased quantity to expand the processing range. 5 CNC high-speed cutting requirements for tool dynamic balance and other requirements In CNC high-speed cutting, dynamic balance issues should be considered. The dynamic balance that affects CNC high-speed cutting is mainly manifested in two aspects: the imbalance between the tool and the tool holder and the imbalance of the machine tool spindle. The tool dynamic balancing accuracy level specified in the safety standard ISO15641 for high-speed rotating tools should be within G40. Therefore, for tools used in CNC high-speed cutting, every aspect of the tool should be fully considered. For example, in the design of end mills, try to use integral tools with good symmetry, use straight handles, and use an even number of teeth. , Tool materials are made of imported materials with better quality. Strictly control the cutting runout, the coaxiality between the cutting edge and the tool holder, and the dimensional accuracy of the cutting edge and tool holder to ensure the dynamic balance requirements of the tool. In the practical application of CNC high-speed cutting tools, in addition to the correct selection of tool materials, cutting parameters and tool dynamic balance, other issues related to the tool must also be considered, mainly including: improving the stiffness of the cutting system; considering the centrifugal force endured by the tool; the need Add special safety features.
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