JP4636557B2 - Replaceable blade cutting tool - Google Patents

Description

  The present invention relates to a blade part replaceable coated cutting tool in which a cutting blade member is coated with a film in a cutting tool in which a cutting blade member is detachably attached to the tip of a tool body.

  A technique related to the surface treatment of the tool body is disclosed in Patent Document 1.

Japanese Patent Laid-Open No. 2003-231006

Patent Document 1 discloses that the surface of a cutting tool holder is colored by black dyeing with a caustic soda solution and subjected to a rust prevention effect treatment. However, the oxide film formed by the black dyeing process tends to peel off, and when applied to a cutting tool, there is a problem that the appearance is impaired by peeling of the film. Furthermore, the oxide film formed by the treatment with black dyeing is formed of scaly iron tetroxide and has pinholes, so it is a treatment that expects a temporary rust prevention effect, and a sufficient rust prevention effect Can't get.
Therefore, the problem to be solved by the present invention is that in the blade part replaceable coated cutting tool in which the cutting blade member is detachably attached to the tool body, in addition to the improvement of the adhesion of the coating coated on the surface of the cutting blade member, An object of the present invention is to provide a blade-part-exchange-type coated cutting tool that is coated with a film having a particularly excellent antirust effect.

The present invention relates to a cutting tool in which a cutting blade member 2 is detachably attached to the tip of a tool body 1, and the cutting blade member 2 has a base portion 4 holding a blade portion 3 on one end side and a base portion 4 on the other end side. A connecting portion 5 for connecting to the tool body 1 is provided, and the cutting blade member 2 is a high-strength material such as high-speed tool steel, alloy tool steel, die steel, etc., and a coating is coated on the surface thereof. The film is composed of at least one of 4a, 5a, 6a group elements, Al, Si, and B coated by arc ion plating (hereinafter referred to as AIP) and sputtering (hereinafter referred to as SP). One or more compounds selected from the contained nitride, carbonitride, oxycarbonitride, and the half-value width W value of the (200) plane of the face-centered cubic structure at the X-ray diffraction peak is Cukα1 in when measured at 2 [Theta], it provided 0.6 ° ≦ W ≦ 1.2 °,該切 A blade portion replaceable coated cutting tool, characterized in that imparted with compressive residual stress in the member 2. By adopting this configuration, in addition to improving the adhesion of the coating film coated on the surface of the cutting blade member, it is possible to provide a blade-part exchange-type coated cutting tool coated with a coating film that has a particularly excellent antirust effect. .

  According to the present invention, in the blade part replaceable coated cutting tool in which the cutting blade member is detachably attached to the tool body, in addition to improving the adhesion of the coating coated on the surface of the cutting blade member, the rust prevention effect is remarkably excellent It was possible to provide a blade-cutting-type coated cutting tool coated with a coating.

FIG. 1 shows an example of the blade part replaceable coated cutting tool of the present invention. In order to detachably attach the cutting blade member 2 to the tool main body 1, the structure is fixed to the tool main body 1 via the connection portion 5. As a connection method, for example, a male screw is formed in the connection portion 5, screwed into the female screw portion 7 provided in the attachment hole 6 of the tool body 1, and screwed into the attachment hole 6 together with the connection portion 5. The blade part can be easily replaced on the machine, which is preferable in terms of work efficiency.
The surface of the cutting blade member 2 is coated with a film. The coating is one or more selected from nitride, carbonitride, oxycarbonitride coated with AIP, SP containing one or more of 4a, 5a, 6a group elements, Al, Si, B A compound. As the coating method, any one of AIP alone, SP alone, or a combination of AIP and SP can be adopted. By adopting these means, since the activated ions having high energy are applied to the surface of the cutting blade member and coated, the adhesion of the coating on the surface of the cutting blade member can be improved. In addition, the base portion 4 having a complicated three-dimensional shape can be coated while the blade member itself revolves, so that the coating is good. Furthermore, the covering area can be easily controlled by applying an appropriate mask process to the connecting portion 5. For example, when the composition of the film is Ti-containing nitride, carbonitride, oxycarbonitride, Cr-containing nitride, carbonitride, oxycarbonitride, the adhesion between the cutting edge member, the substrate and the film Can make significant improvements. By containing O or C in the film, an oxidation protective film formed on the surface of the film is formed at an early stage and has an excellent antirust effect and welding resistance. By replacing one part of N in the film with O or C, a large strain is generated in the crystal lattice, a larger compressive residual stress is generated, and high hardness can be realized.

The constituent elements of the coating used in the present invention contain a combination of elements with different ionic radii, resulting in large strain in the crystal lattice and greater compressive residual stress compared to the film thickness. Therefore, it is preferable. This is because the film has a high hardness. The coating is based on Ti, and in addition, if one or more of 4a, 5a, 6a group elements such as Nb, Cr, W, V, Zr, Mo, Al, Si, B are selected, the coating is More heat resistance and fracture resistance can be imparted, and this effect provides an excellent rust prevention effect. In addition, when Ti is replaced with Cr, a film having further excellent heat resistance can be realized. When the film contains one or more elements of the 4a, 5a, and 6a group elements, the film can have high hardness and heat stability, and therefore wear resistance and heat resistance can be obtained when used as a cutting tool. On the other hand, even if only TiN, ZrN, and HfN are contained, if one or more of Al, Si, and B are not contained, the following inconvenience occurs. Furthermore, the film used in the present invention preferably contains S. As a result, when used as a cutting tool, an oxidation protection film is formed on the surface of the film at a relatively early stage before the surface of the film reaches a high temperature. An effect can be obtained. Furthermore, excellent welding resistance can be realized even during use as a cutting tool. The blade part replaceable coated cutting tool of the present invention has a more excellent rust-proofing effect and resistance because the amount of S contained in the coating is 0.3% or more and 10.0% or less in atomic%. It has weldability and is preferable. If the amount of S is less than 0.3%, the effect of S is weak, and if it exceeds 10.0%, the crystallinity of the film is deteriorated, and the oxidation resistance and wear resistance affecting the rust prevention effect are lowered. A trend appears.
Here, in order to contain S, there is a method of using a reaction gas, but for safety and environmental considerations, S is contained in the target, and this is evaporated and ionized by arc discharge, glow discharge or the like. Therefore, it is preferable to form an S-containing film.

By making the crystal structure of the film a face-centered cubic structure, it is preferable because a hard film with higher hardness and excellent wear resistance and heat stability can be obtained. On the other hand, when the face-centered cubic structure is not used, the hardness is slightly lowered and the wear resistance tends to be lowered. When the half-value width W value of the (200) plane at the X-ray diffraction peak of the film is measured by Cukα1, by setting 0.6 ° ≦ W ≦ 1.2 ° at 2θ, a film having crystallinity is obtained. Therefore, it is preferable. A hard film having a large compressive residual stress and excellent wear resistance can be obtained. When the half width W value is less than 0.6 degrees, the strain in the film becomes too large, and internal defects such as dislocations increase, resulting in a drawback that the mechanical strength is remarkably lowered. On the other hand, if it exceeds 1.2 degrees, the crystallinity of the film is lowered, and there is a disadvantage that the film hardness and the wear resistance are greatly lowered. Furthermore, the adhesiveness is deteriorated and the defect resistance is remarkably lowered.
A film in which the half width W value of the (200) plane at the X-ray diffraction peak is 2θ and 0.6 degrees ≦ W ≦ 1.2 degrees can be obtained by controlling the film forming conditions. For example, it is preferable to set the pressure in the range of 3 to 10 Pa, increase the plasma density generated during film formation, and set the DC bias voltage in the range of 15 to 300 V. When the pressure is set lower than 3.0 Pa, the half-value width W value is increased and easily exceeds 1.2 degrees. However, when it exceeds 10 Pa, it is less than 0.6 degrees. When the bias voltage is set to less than 15V, the half-value width W value becomes small and is less than 0.6 degrees. However, when it exceeds 300V, it tends to be larger than 1.2 degrees. However, since the optimum film forming conditions depend on the target and the film forming apparatus to be used, it is necessary to find and adjust the optimum value by experiment in consideration of film adhesion and the like.

  In the blade part replaceable coated cutting tool of the present invention, in order to provide the blade part by mounting the insert on one end side of the cutting blade member, it is preferable that a base part for holding the insert is provided. The blade portion is formed by mounting the insert on the base portion. Appropriate selection of the shape of the base portion and the shape of the cutting edge of the insert is preferable because it can be applied to various cutting tools with interchangeable blades such as milling tools, end mills, drills, and turning tools.

  In the present invention, it is possible to select optimum materials for the cutting blade member and the tool main body, respectively. For example, it is preferable that at least a part of the cutting blade member is a high-strength material such as a steel material such as high-speed tool steel, alloy tool steel, or die steel. Further, when the tool body is a high-hardness material such as a cemented carbide, it is preferable because the rigidity and wear resistance of the tool are improved. By forming the cutting blade member by an injection molding method, the diameter of the cutting blade member can be reduced. Further, the coating treatment of the present invention can also be applied to the head of a mounting screw for fixing the insert, a clamp piece, a wedge, and the like. Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Example 1
The tool of the present invention shown in FIG. 1 is a blade part exchange-type coated cutting tool having a blade diameter of 25 mm and two inserts attached thereto. The cutting blade member was made of HRC45 SKD61 material, and the cutting blade member and the tool main body were integrated by screwing and fitting of the brazing portion to produce the cutting tool of the present invention. The surface of the cutting blade member was coated with a film using the AIP method and the SP method. The coating material was coated with one or more compounds selected from nitride, carbonitride, and oxycarbonitride. The reaction gas used was selected from nitrogen, methane, acetylene, a mixed gas of argon and oxygen, and a mixed gas of nitrogen and oxygen to obtain a target film. As the evaporation source, various alloy targets were selected and used. A Ti target was used for coating the cutting blade member of Example 1 of the present invention. The coating temperature was 500 ° C., the reaction pressure was 6.0 Pa, the TiN film was formed with a DC bias voltage of 50V. Invention Examples 2 to 14, Comparative Examples 15 and 16, Invention Examples 17 to 25, Comparative Example 26 and Invention Examples 27 to 30 are based on the film formation conditions of Invention Example 1 unless otherwise specified. The average film thickness was set to about 2 μm. On the other hand, in the conventional example 31, the cutting blade member having the same shape as the example of the present invention was subjected to black dyeing treatment under normal conditions. The film thickness of the black film of triiron tetroxide was 2 μm. The prepared samples are shown in Table 1.

Inventive Examples 1 to 9 having a Ti-based composition and a Cr-based composition were prepared by setting the bias voltage condition to 50 V using the AIP method. Inventive Examples 10 to 30 having S component in the coating composition were prepared. Among them, Invention Examples 10 to 14 and Comparative Examples 15 and 16 having different half-value width W values of the films were produced by changing only the bias voltage in a range of 20 V to 350 V. Inventive Examples 17 and 18 were prepared using TiBS and TiSiS as target materials and adding B and Si into the coating. In order to add Cr and Nb to the target, AIP method and SP method were used in combination to apply a large compressive residual stress to the film, and inventive examples 19 and 20 having high hardness were produced. Invention Examples 21 to 25 and Comparative Example 26 were produced in which the S content in the target was changed to change the S content of the film. Inventive Examples 27 to 29 were prepared by introducing oxygen or hydrocarbon-based gas such as methane or acetylene during film formation, and containing oxygen or carbon in the film. Invention Example 30 was produced by substituting Cr for the target composition used in Invention Example 10 with Cr.
The S content of the example of the present invention was measured with an energy dispersive X-ray analyzer (S-792X1, manufactured by Horiba, hereinafter referred to as EDX), and the X-ray diffraction pattern of the film was measured with an X-ray diffractometer (Rigaku Corporation) ) -Made RU-200BH), the X-ray diffraction pattern was measured in the range of 2θ = 10 to 145 degrees by the 2θ-θ scanning method. CuKα1 ray (λ = 0.15405 nm) was used as the X-ray source, and background noise was removed by software built in the apparatus. As a result of the measurement, in Examples 1 to 30 of the present invention, the detected 2θ peak position substantially matched the X-ray diffraction pattern (JCPDS file number 38-1420) of TiN whose crystal structure is a face-centered cubic structure. The half width W value of the (200) plane peak was measured. These evaluation results are shown in Table 1.
Further, the coated cutting blade member was exposed to an environment that promotes corrosion, and evaluated by repeated tests of drying and wetting using an environmental testing machine. The test conditions were left for 3 days in an atmosphere at a temperature of 40 ° C. and a humidity of 98%, and then a total of 7 days for 4 days in an atmosphere at a temperature of 23 ° C. and a humidity of 60% was defined as one cycle. This was performed continuously for 4 cycles, and the evaluation was performed every cycle. The evaluation results are shown in Table 1.
From this test result, it was confirmed that the cutting blade member subjected to the coating treatment of the present invention did not show any red rust and had a high antirust effect. In particular, the present invention examples 1 to 14, 17 to 25, and 27 to 30 in which the half width W value of the ( 200) plane is 2θ and is in the range of 0.6 degrees ≦ W ≦ 1.2 degrees are 3 At the end of the cycle, no rust was seen and a high rust prevention effect was shown. This is because a dense film having good crystallinity was formed. On the other hand, with the conventional black-dyed product, a satisfactory antirust effect was not obtained.

By the cutting test, the adhesion of the film, the peeling due to abrasion during the cutting process, the damage state due to wear and the adhesion state of the welded material were visually evaluated. The cutting test conditions for the tool were divided into two types. In test condition 1, the adhesion evaluation of the film by milling was performed. In test condition 2, the damage state due to wear of the film by helical processing and the adhesion state of the welded material were evaluated. The drilling conditions by helical cutting, which are likely to cause damage due to chip welding and abrasion, increase the machining depth as machining progresses, making it difficult to discharge chips. Therefore, chip welding and damage to the tool body become significant. The machining shape was set so that the hole diameter was 40 mm and the machining depth was 30 mm. Evaluation was performed under the following conditions.
(Test condition 1)
Cutting method: Milling Work material: S50C material Cutting speed: 120 m / min (rotation speed: 1530 rotations / minute)
Table feed rate: 1530 mm / min (feed rate of 1 blade: 0.5 mm / blade)
Table feed rate: 1530 mm / min (feed rate of 1 blade: 0.5 mm / blade)
Axial depth of cut (Ad): 0.5 mm
Radial depth of cut (Rd): 8.0 mm
(Test condition 2)
Cutting method: drilling by helical cutting Work material: S50C, hardness, HB220
Cutting speed: 120 m / min (rotation speed: 1530 revolutions / minute)
Table feed rate: 1530 mm / min (feed rate of 1 blade: 0.5 mm / blade)
Helical pitch: 1.0mm
Cutting oil: None (dry cutting)

In test condition 1, after performing a continuous cutting test for 20 hours, the state of the coating on the surface of the cutting blade member was observed. About the example of the present invention and the comparative example , the state in which the film was covered was maintained, and the excellent adhesion of the film could be confirmed. On the other hand, in Conventional Example 31, a portion of the oxidized black film was peeled off by rubbing with chips, and the skin surface exposure of the cutting blade member was observed. In particular, a severe rubbing state was observed on the outer peripheral surface around the base portion to which the insert was attached, the bottom surface following the cutting edge, and the chip pocket portion.
Under the test condition 2, when the surface of the cutting blade member was observed when the drilling process was repeated 5 times, no remarkable morphological changes were observed in the inventive examples and the comparative examples, and the results were good. However, in the conventional example 31, scratches on the oxidized black film and adhesion of chips were observed. In particular, severe rubbing was observed on the outer peripheral surface, bottom surface and chip pocket portion around the base portion to which the insert was attached. Then, when the present invention example was continuously used and the drilling member surface was observed again when the drilling process was repeated 20 times, the film containing the S component was more than the film containing no S component. The amount of chip adhesion was small. This is because, since it contains S, an oxidation protective film was formed on the surface of the film at the initial stage of cutting, and excellent welding resistance was obtained. Further, in Examples 19 and 20 of the present invention in which Cr and Nb were contained in the film, the abrasion state of the film was small. This is because a large residual compressive stress is applied, and the film is hardened. Invention Examples 27, 28, and 29 contained carbon and oxygen in the film, so that there were few welds. This is because when the film contains O or C, the film surface has excellent lubricating properties.

FIG. 1 shows a blade exchangeable coated cutting tool of Example 1 of the present invention.

1: Tool body 2: Cutting blade member 3: Blade portion 4: Base portion 5: Connection portion (male screw portion)
6: Mounting hole 7: Female thread

Claims (1)

In a cutting tool in which a cutting blade member 2 is detachably attached to the tip of a tool body 1, the cutting blade member 2 has a base portion 4 that holds a blade portion 3 on one end side, and the tool body 1 on the other end side. The cutting edge member 2 has a high-strength material such as high-speed tool steel, alloy tool steel, die steel, and the surface thereof is coated with a coating, One or more selected from nitride, carbonitride, oxycarbonitride containing at least one of 4a, 5a, 6a group elements, Al, Si, B coated by arc ion plating and sputtering When the half-value width W value of the (200) plane of the face-centered cubic structure at the X-ray diffraction peak is measured by Cukα1, 2θ is 0.6 ° ≦ W ≦ 1.2 ° provided, the blade portion replaceable, characterized in that imparted with compressive residual stress in the cutting edge member 2 Covering a cutting tool.

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