TW201936300A - Cutting tool and manufacturing method therefor - Google Patents

Abstract

Provided is a cutting tool having both good adhesion resistance and smoothness and a manufacturing method therefor. The cutting tool is constituted by a composite material including a ceramic phase and a metal phase, wherein a cutting edge portion of the cutting tool has a cutting edge ridgeline and a cutting edge constituting surface which forms the cutting edge ridgeline. The cutting edge constituting surface has a surface portion in which the ceramic phase protrudes from the composite material layer including the ceramic phase and the metal phase, the ceramic phase is present intermittently, and the metal phase is absent. The surface roughness of the surface portion is represented by an arithmetic mean roughness Ra ≤ 0.1 [mu]m and a skewness Rsk ≤ -0.01.

Description

Cutting tool and its manufacturing method

The invention relates to a cutting tool with good durability and a manufacturing method thereof.

A composite alloy including a composite material having a hard phase typified by ceramics and a metal phase typified by Ni, Co, Fe, etc. is used in tools and jigs due to its excellent impact resistance at room temperature and high temperature. For example, the composite material is also applied to a cutting blade for cutting paper, resin film, metal plate, etc., and various studies have been conducted since then. For example, cited document 1 describes a cutting blade characterized in that the cutting blade includes at least one selected from the group of Cr, V, and Ta containing 0.3 mass% to 3.0 mass% in total in terms of carbide. And 8% by mass to 15% by mass of Co, the remainder is a cemented carbide of WC particles with an average particle size of 0.1 μm to 0.5 μm. Furthermore, cited document 2 describes a method for cutting or cutting a multilayer capacitor, a multilayer ceramic substrate, etc., or a ceramic green sheet, with a particle size including WC of 1.0 μm or less and a Co content of 8% as a bonding phase A thin cutting blade featuring ~ 20% cemented carbide. [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2004-291137 [Patent Document 2] Japanese Patent Laid-Open No. 2002-86387

[Problems to be Solved by the Invention] In the above-mentioned composite alloy cutting tool, if the workpiece is a metal material or an amorphous (amorphous) thin strip, there is adhesion due to contact between metals , And such problems as abrasion or chipping occur. If the abrasion occurs on the blade, burrs are generated on the end surface of the workpiece to be cut due to a decrease in sharpness, so the accuracy required by the product cannot be achieved. Therefore, with further precision requirements or use in a more severe environment, it is required to further improve the adhesion resistance while maintaining the smoothness and sharpness of the working surface of the cutting tool so as not to generate abrasion powder when attacking the processed material. In response to the request, the invention of Patent Document 1 is an excellent invention for increasing the hardness of the surface of cemented carbide. However, there is no description on the suppression of the deterioration of the surface state caused by the removal of Co, and there is room for research. Moreover, the invention of Patent Document 2 is an invention in which irregularities are formed on the surface in order to improve the adhesion of the diamond film, and particularly in a precision cutting tool, there is a possibility that the desired surface quality cannot be obtained. An object of the present invention is to provide a cutting tool having good adhesion resistance and smoothness, and a method for manufacturing the same. [Means to solve the problem]

The present invention has been made in view of the aforementioned problems. That is, one aspect of the present invention is a cutting tool including a composite material containing a ceramic phase and a metal phase. The cutting tool is characterized in that a cutting edge portion of the cutting tool has a cutting edge ridge line and constitutes a cutting edge ridge A line blade formation surface having the ceramic phase protruding from the composite material layer having the ceramic phase and the metal phase and intermittently existing the ceramic phase and lacking the surface portion of the metal phase The surface roughness of the surface portion satisfies the arithmetic average roughness Ra ≦ 0.1 μm and the skewness Rsk ≦ −0.01. Preferably, the skewness Rsk ≦ -1.0 of the surface of the cutting tool. Preferably, the ceramic phase is WC or TiC, and the metal phase is at least one selected from Co, Ni, and Fe. The preferred feature is that at least one layer of carbide, nitride, oxide, carbonitride or at least one element selected from the group consisting of group 4a, group 5a and group 6a is formed on the surface portion Boron film, or diamond-like carbon film.

Furthermore, another aspect of the present invention is a method for manufacturing a cutting tool, which is a method for manufacturing a cutting tool including a composite material containing a ceramic phase and a metal phase. The method for manufacturing a cutting tool is characterized by: The cutting edge portion of the cutting tool has a cutting edge ridge line and a cutting edge configuration surface constituting the cutting edge ridge line, and the manufacturing method of the cutting tool includes a shape processing step in which a tool base material including the composite material is a cutting edge configuration surface The portion of the tool base is adjusted to Ra ≦ 0.1 μm by grinding processing; and a surface improvement step, after the shape processing step, the portion of the tool base material adjusted to Ra ≦ 0.1 μm that becomes the blade formation surface is etched and removed The metal phase forming part of the blade-forming surface is configured such that the blade-forming surface has the ceramic phase protruding from the composite material layer having the ceramic phase and the metal phase, and the ceramic phase intermittently exists The surface portion of the metal phase is absent, and the surface roughness of the surface portion becomes Rsk ≦ -0.01. Preferably, the surface improvement step is wet etching using an acid solution. [Effect of invention]

According to the present invention, a cutting tool having good adhesion resistance and smoothness can be obtained.

Hereinafter, the present invention will be described in detail. However, the present invention is not limited to the embodiments listed here, and can be appropriately combined or improved without departing from the technical idea of the invention. The cutting tool of the present invention is a cutting tool including a composite material in which a ceramic phase (hereinafter also referred to as a hard phase) and a metal phase as a binder (bonding phase) are mixed. The cutting tool is characterized by having both the advantages of a hard phase (excellent strength) and the advantages of a metal phase (high ductility and toughness).

The ceramic phase of the cutting tool of the present invention is preferably selected from W (tungsten), Cr (chromium), Mo (molybdenum), V (vanadium), Zr (zirconium), Al (aluminum), and Si (silicon) , Nb (niobium), Ta (tantalum), and Ti (titanium) at least one of carbide, nitride, carbonitride, oxide, and boride. More preferably, it is at least one kind selected from the group consisting of carbides, nitrides, carbonitrides, oxides, and borides of W or Ti. Furthermore, the metal phase of the cutting tool of the present invention is preferably selected from at least one of Co (cobalt), Ni (nickel), Fe (iron), W (tungsten), and Mo (molybdenum). More preferably, it is at least one selected from Co, Ni, and Fe. Unless otherwise specified, the cutting tool of the present embodiment includes a WC-Co composite material in which tungsten carbide (WC) is selected for the ceramic phase and Co is selected for the metal phase.

FIG. 1 shows a schematic view of a cylindrical knife (hereinafter also referred to as a slit knife) which is an example of a cutting tool of the present embodiment. The present invention can be used in a cutting tool such as a punch for punching, in addition to the cylindrical knife. Furthermore, it can also be applied to shearing tools such as shearing blades having sharp wedge angles. The cylindrical knife of the present embodiment is used in a cutting machine that cuts a metal strip 12 to a metal strip 13 of a desired width as shown in FIG. 1, and the cylindrical upper knife 1A and the cylindrical upper knife are arranged at a fixed interval. The cylindrical lower blade 1B cuts the workpiece by shearing the upper blade and the lower blade. The cylindrical blade has a blade ridge line 4 (solid white line), a blade configuration surface 6 that constitutes the blade, and a blade configuration surface 7 (hereinafter, the blade configuration surface 6 is also described as an outer peripheral surface, and the blade configuration surface 7 is described For the side). The enlarged view of part A of the cutting tool in FIG. 1 is shown in FIG. 2. As shown in FIG. 2, the cutting tool of the present embodiment is characterized by including a composite material containing a ceramic phase 2 and a metal phase 3 on a blade ridge line 4 and a blade configuration surface 6 and a blade configuration surface that constitute a cutting edge of the cutting tool 7 includes the ceramic phase 2 protruding from the composite material layer, the ceramic phase 2 intermittently (discontinuously) in the in-plane direction of the blade forming surface 6 and the blade forming surface 7, and lacking the surface portion of the metal phase 3, the blade The surface roughness of the constituent surface 6 and the blade constituent surface 7 satisfies: arithmetic average roughness Ra ≦ 0.1 μm and skewness Rsk ≦ −0.01. Here, "the surface portion where the ceramic phase intermittently exists and lacks the metal phase" means that there is substantially no metal phase. As in the embodiment of the manufacturing method described later, the blade ridge line and the blade constituent surface are produced by removing the metal phase from the portion of the tool base material shown in FIG. 3 including the ceramic phase and the metal phase that becomes the blade ridge line and the blade constituent surface . By the removal of the metal phase, the blade ridge line of the cutting tool of the present embodiment forms a concave portion 5 that is recessed toward the center of the rotating shaft from the portion that contacts the workpiece, thereby forming an intermittent blade ridge line. By having the blade ridge line described above, the cutting tool of the present embodiment improves the bite performance to the material to be processed, thereby suppressing the reduction of the shear stress caused by the sliding of the material to be cut near the cutting edge and improving the cutting Break performance. In addition, the blade formation surface also has a surface portion in which a ceramic phase intermittently exists and lacks a metal phase, similar to the blade ridge line, whereby it can be set that the blade ridge line and the blade formation surface of the cutting tool do not have softness and are easily adhered. Due to the metal phase of the material to be processed, the adhesion resistance of the cutting tool can be improved. Furthermore, good cutting can be performed without generating a defective state of the cut surface such as a secondary shear surface or excessive burrs on the cut surface of the workpiece. In addition, since the uneven surface of the blade is appropriately formed with irregularities, the tool tends to easily fall off from the workpiece during cutting. Thereby, the effect of suppressing the entanglement of the burr generated in the processed material and reducing the mixing of the broken burr into the product can be expected. In addition, the blade ridge line of the cutting tool of this embodiment is discontinuous as described above, and the ceramic phase forming the blade ridge line is intermittent as shown in FIG. 2, but it can be smoothly connected with a straight line and a curve with a fixed curvature (The dotted line portion 5a is a virtual blade ridge line). With the shape of the blade, the bite performance of the blade can be improved, and smooth cutting can be performed.

In this embodiment, in the removal of the metal phase, there may be a part that is not completely removed, so it is explained that there is substantially no metal phase. When compared with the majority of the cutting tool including the ceramic phase and the metal phase (substrate portion), the amount of metal phase present in the blade ridge line and the blade formation surface is significantly different, making it easy to determine that there is substantially no metal The phase includes the ceramic phase. Furthermore, the blade ridge line and the blade formation surface may include materials other than the ceramic phase and the void, or the ceramic phase and the metal phase filling the void. The void is formed by removing the metal phase, and may be a void at all times, or the void may be filled with a material other than the metal phase. For example, by filling the voids with a resin-based material mainly composed of polytetrafluoroethylene, it is possible to exert effects such as preventing the exposure of the metal layer and suppressing the shedding of hard particles. Furthermore, by filling the resin-based material, an effect of suppressing the entanglement of burrs generated in the workpiece can also be expected. Of course, some voids may remain.

The portion (surface portion) constituted by the ceramic phase protruding in this embodiment is preferably formed in a range of at least 0.2 μm in the depth direction from the blade formation surface. With this, the adhesion resistance can be further improved (hereinafter, the layered portion formed along the in-plane direction of the blade formation surface including the ceramic phase from which the metal phase is removed is also referred to as a hard reinforcement layer). The thicker the hardened layer, the longer the period of time when the advantageous effect is obtained, so it is more preferable to form a range of 0.5 μm from the blade formation surface in the depth direction (direction perpendicular to the blade formation surface), particularly preferably Form a range to 1 μm. In addition, as will be described later, a coating layer may be formed on the blade formation surface. In addition, at this time, the range of the surface portion (hard reinforcement layer) in the depth direction represents the depth from the blade-constituting surface in the state where there is no coating layer. In addition, in order to make it easier to form voids formed in the hard reinforcement layer, the cutting tool of the present invention preferably has a diameter of the ceramic phase of 1 μm or more. In addition, the diameter of the ceramic phase can be obtained from the average value of the circle-equivalent diameter of the ceramic phase existing in the field of view by observing the surface and the cross section of the cutting tool at a magnification of 3,000 to 20,000 times, for example. The upper limit of the thickness of the hardened layer is not particularly limited, and it may be about 15 μm in production. In addition, according to the manufacturing method of the present invention described later, the hardened layer is formed almost uniformly on the entire blade ridge line and the blade constituent surface by etching, so as long as a scanning line electron microscope (scanning electron microscope (SEM) is used) ), Etc., for example, it may be sufficient to confirm the range of about 10 μm to 20 μm in the in-plane direction on the cross section of the blade formation surface.

In addition, it is preferable that the ratio of the area of the ceramic phase to the total of the area of the ceramic phase and the area of the metal phase at the cross-sectional area ratio be the ratio of the ceramic phase to the main part of the cutting tool Compared with the ceramic ratio of the hardened layer, the ceramic ratio of the hardened layer is higher, and the ceramic ratio of the hardened layer is more than 99%. An example of a method for measuring the ceramic ratio is shown. First, the blade constituent surface of the cutting tool is cut in a direction orthogonal to the surface, and a photograph is taken at a predetermined magnification using a scanning electron microscope (SEM) so that the blade constituent surface enters the field of view. The substantially flat or curved blade formation surface which is the contact surface with the material to be processed is connected by the line A, and the line A is made to the depth of the cutting tool at a position of at least 0.2 μm in the depth direction from the blade formation surface Line B moving in parallel. Then, the ratio of the area occupied by the ceramic phase when the area ratio after removing the void from the area surrounded by the line A, the line B, and the photo end is 100% is the ceramic comparison ratio. In addition, the “substantially flat surface” in the present embodiment refers to a shape in which the entire surface can be regarded as a flat surface except for the minute irregularities existing on the upper surface of the ceramic phase that becomes the contact surface.

In the cutting tool of this embodiment, it is also important that, among the roughness of the blade-constituting surface, the arithmetic mean roughness Ra (according to JIS-B-0601-2001) is 0.1 μm or less, and the skewness Rsk is −0.01 or less . As a result, in the cutting tool of the present invention, in the roughness curve of the blade-forming surface in contact with the workpiece, the convex portion becomes wider than the concave portion, and the formation of sharp convex portions can be suppressed. The convex portion of the contact surface is a starting point of wear or seizure, and thus exhibits good sliding characteristics. Moreover, for example, if the contact surface between the cutting tool and the workpiece is smooth and lubricating oil is used during cutting, it is difficult to impregnate the lubricating oil to the parts where the contact surfaces are in contact with each other. However, in the present invention, Rsk is used It is -0.01 or less, thereby forming an appropriate concave portion (hereinafter, also referred to as a void) on the working surface of the cutting tool, whereby the impregnability of the lubricating oil can be improved and good sliding characteristics can be exerted. In addition, when the working surface of the cutting tool and the material to be processed is smooth, there is a possibility of vacuum adhesion. However, the concave portion prevents the contact surface of the cutting tool and the material to be in a vacuum state. And by the above effect, good sliding characteristics can be obtained. Even in order to obtain the above effect more reliably, the Rsk of the present invention is preferably -1.0 or less. In addition, it is preferable that the blade ridge line of this embodiment also has the same roughness curve as the blade configuration surface. The present invention exerts an effect when the material to be processed includes a metal material. In particular, for the amorphous alloy thin strip that has been difficult to process, if the cutting tool of the present invention is used, stable cutting can also be expected.

In order to further improve the abrasion resistance, the cutting tool of this embodiment may form carbides and nitrides including at least one element selected from the group consisting of Group 4a, Group 5a and Group 6a on the blade ridge line and surface portion , Oxide, carbonitride or boride film. It is preferable to apply a film including Cr-based nitride, Ti-based nitride, or Ti-based carbonitride. Particularly preferred are coatings including TiCN, AlCrN, TiSiN, TiAlN, AlCrSiN, TiAlSiN, TiAlCrSiN. In the case of applying AlCrSiN, in order to further improve the wear resistance, the composition formula of Al _x Cr _y Si _z (x + y + z = 100) is preferably controlled to be 20 <x <75､25 <y <75 ､ 0 <z <10, more preferably 50 <x <55､45 <y <50､0.1 <z <1. Furthermore, in the case of applying TiAlSiN to the film, the composition formula of Ti _x Al _y Si _z (x + y + z = 100) is preferably controlled to be 25 <x <75､20 <y <75 <0.0､0.0 <z <10 range. The preferable film thickness of the film is 0.1 μm to 5.0 μm, and the more preferable film thickness is 0.5 μm to 2.0 μm. The reason is that if the film thickness is too thick, there are protrusions that cannot trace the ceramic phase, and there is a possibility that the advantageous effects such as the adhesion resistance may not be exerted. If the film thickness is too thin, there is The possibility that the wear resistance improvement effect cannot be fully obtained. Here, when an Al _x Cr _y Si _z N film is used, it may have an inclined composition in which the x value increases from the substrate side toward the film surface side and the y value decreases. By this, the adhesion strength with the base material can be further improved. Further, regarding the surface roughness of the film, it is preferable that the arithmetic average roughness Ra is 0.06 μm or less and the maximum height Rz is 1.0 μm or less. By this, the unevenness on the surface of the film can be suppressed from being the starting point of friction, thereby further improving the wear resistance.

The cutting tool of this embodiment may apply a diamond-like carbon film (hereinafter also referred to as DLC film) in addition to the above-mentioned film. The DLC film can also improve the abrasion resistance of the cutting tool. The DLC film also forms irregularities on the surface of the film in a manner that imitates the irregularities on the surface of the hardened layer, so it can be expected to also play a role by providing the gap advantage. For the DLC film, in order to obtain higher hardness and to improve the adhesion with the cutting tool, the content of hydrogen atoms in the surface of the DLC film may be set to 0.5 atom% or less, and the nitrogen content to 2 atoms %the following. Furthermore, by setting the hydrogen content in the interface side of the DLC film and the hardened layer to be 0.7 atomic% or more and 7 atomic% or less, and the nitrogen content to be more than 2 atomic% and less than or equal to 10 atomic%, further wear resistance can be expected Consumable improvement. The content of the hydrogen atom can be determined by, for example, the elastic rebound particle detection method (Elastic Recoil Detection Analysis (ERDA) analysis). Moreover, the content of nitrogen atoms can be obtained by, for example, Auger electron spectroscopy (Auger electron spectroscopy (AES)).

In order to impart abrasion resistance or heat resistance, the DLC film may contain metallic (including semi-metallic) elements, as long as the compounds of metals, alloys, carbides, nitrides, carbonitrides, carbonitrides, carboborides, etc. The form can be contained. The content ratio (atomic%) of metal (including semimetal) elements is preferably 2% or more, and particularly preferably, it can be set to 5% or more. However, when the content ratio of metal (including semimetal) elements increases, the sliding characteristics tend to decrease. Therefore, the content ratio (atomic%) of metal (including semimetal) elements can be set to 20% or less, more preferably 10% or less. In addition, the thickness of the DLC film can be set to 0.1 μm to 1.5 μm or 0.1 μm to 1.2 μm in order to further improve the durability or the adhesion to the metal mold, in order to provide sufficient wear resistance to the metal mold The film thickness of the DLC film can also be set to 0.2 μm or more. In order to achieve smooth surface roughness and excellent wear resistance at the same time, the film thickness of the DLC film may be set to 0.6 μm to 1.2 μm. The surface roughness of the DLC film is also preferably: the arithmetic average roughness Ra is 0.06 μm or less, and the maximum height roughness Rz is 1.0 μm or less. If the Ra has a smoothness of 0.03 μm or less and Rz of 0.5 μm or less, it is possible to reduce surface defects that become the starting point of welding of the workpiece. It is particularly preferable that Ra is 0.02 μm or less and Rz is 0.3 μm or less.

Next, the manufacturing method of the present invention will be described. The manufacturing method of the present invention is characterized by having a shape processing step such that a portion of the tool base material including a composite material containing a ceramic phase and a metal phase that becomes a blade-constituting surface is Ra ≦ 0.1 μm; a surface improvement step is based on the shape After the processing step, the surface of the tool base material adjusted to Ra ≦ 0.1 μm is etched to remove the metal layer near the surface. The tool base material including the composite material can be produced by a known method, for example, it can be obtained by pressing and molding a mixed powder of ceramic powder and metal powder into a predetermined shape, and then, under a vacuum environment Sintering is carried out at a temperature of 1250 ° C to 1550 ° C. In addition, in order to further increase the strength of the cutting tool, the mixed powder used in the manufacturing method of the present invention is preferably a volume ratio of metal powder of 3% to 30 when the total volume of ceramic powder and metal powder is 100% %. Moreover, the ceramic powder is preferably selected from W (tungsten), Cr (chromium), Mo (molybdenum), V (vanadium), Zr (zirconium), Al (aluminum), Si (silicon), Nb (niobium) At least one of Ta (tantalum) and Ti (titanium) is selected from carbide, nitride, carbonitride, oxide, and boride. More preferably, it is selected from carbides, nitrides, carbonitrides, oxides, and borides of W or Ti. The metal powder is preferably selected from at least one of Co (cobalt), Ni (nickel), Fe (iron), W (tungsten), Mo (molybdenum), more preferably from Co, Ni, Fe Choose from at least one.

<Shape processing step> In the manufacturing method of the present invention, the surface of the portion of the prepared tool base material that becomes the blade formation surface is adjusted to Ra ≦ 0.1 μm by grinding, grinding, cutting, electrical discharge machining, etc. Shape processing steps. By the shape processing step, the surface of the cutting tool, especially the blade configuration surface that becomes the working surface, is smoothed, whereby the cutting tool formed after the subsequent surface improvement step can be formed into the following hardened layer, namely : A hard reinforced layer with smooth and moderate recesses and a surface roughness of Ra ≦ 0.1 μm and skewness Rsk ≦ -0.01 is formed. The upper limit of the more preferable Ra is 0.05 μm, and the upper limit of the more preferable Ra is 0.02 μm. The lower limit is not particularly limited, and considering mass productivity, it can be set to 0.005 μm, for example. Here, the shape processing step can be combined with a plurality of steps, for example, it can be adjusted to Ra ≦ 0.1 μm by grinding and finishing after roughing by grinding. In this case, a known polishing method can be used for polishing, and buffing polishing using diamond paste can also be performed in order to obtain a desired surface roughness reliably.

<Surface improvement step> Next, in the manufacturing method of the present invention, after performing the shape processing step, the tool base material whose portion constituting the blade formation surface is adjusted to Ra ≦ 0.1 μm is etched to remove the metal phase near the surface Surface improvement steps. FIG. 3 is an enlarged schematic view of the tool substrate before the surface improvement step. Through the surface improvement step, the metal phase 3 is removed, whereby the blade ridge line and the blade constituent surface can be made into a ceramic phase as shown in FIG. 2 protruding from the composite material layer having the ceramic phase and the metal phase, The ceramic phase intermittently exists but lacks the structure of the metal phase. In the present invention, etching is applied to the surface improvement step. For the etching, wet etching using an acidic solution or an alkaline solution or dry etching using a discharge plasma can be used. More preferably, it is easy to make the hard strengthening layer including the ceramic phase thick, and it is easy to stably adjust Rsk to a negative value by wet etching. With the above surface improvement step, the Ra of the blade-constituting surface may become larger than that of the shape processing step, but it can also be used to remove minute machining chips that have bitten into the processing surface by etching during grinding processing, so There are also cases where the smoothness improves and Ra becomes small.

In this embodiment, when wet etching is applied to the surface improvement step, an acidic solution such as hydrochloric acid, nitric acid, or nonaqueous water may be used for the etching solution. However, it is preferable to use a metal phase with high removal ability, and it is easy to strengthen the hard The layer formed by the water. Here, when wet water is used for wet etching, in order to reliably adjust Rsk to a value of -1.0 μm or less, the etching treatment time is preferably more than 30 seconds. A better processing time is 60 seconds or more, and a particularly preferable processing time is 90 seconds or more. In the case where dry etching is applied to the surface improvement step, existing methods can be applied. In the embodiment, for example, the chamber in which the plasma is generated is set to a reduced-pressure Ar environment of about 2 Pa, the Ar gas is made into a plasma, and a bias voltage of -300 V is applied to the substrate to etch. A cutting tool having a desired hardened layer is obtained. In addition, if the above-mentioned treatment is performed on the blade formation surface, the blade ridge line may be formed discontinuously.

In the manufacturing method of the cutting tool of the present invention, in order to further improve the wear resistance, the blade ridge line and the blade surface may be coated with at least at least one element selected from the group consisting of Group 4a, Group 5a, and Group 6a. A coating of carbide, nitride, oxide, or boride. It is preferable to apply a film including Cr-based nitride, Ti-based nitride, or Ti-based carbonitride. Particularly preferred are coatings including TiCN, AlCrN, TiSiN, TiAlN, AlCrSiN, TiAlSiN, TiAlCrSiN. In the case of applying AlCrSiN, in order to further improve the wear resistance, the composition formula of Al _x Cr _y Si _z (x + y + z = 100) is preferably controlled to be 20 <x <75､20 <y <75 The range of ､ 0 <z <10 is more preferably controlled to be within the range of 50 <x <55 <45 <45 <y <50 <0.1 <z <1. Moreover, in the case of applying TiAlSiN to the film, the composition formula of Ti _x Al _y Si _z (x + y + z = 100) is preferably controlled to be 20 <x <75､25 <y <75､0.0 <z <10 range. As the film forming method of the film, a physical vapor deposition (PVD) method can be used, but it is preferable to use a sputtering method that can obtain a smoother film surface with fewer droplets to form the film . In the case of using the sputtering method, in order to further improve the surface smoothness and the adhesion strength between the cutting tool and the film, it is more preferable to set the bias voltage applied to the substrate to 40 V to 150 V.

In addition, in the manufacturing method of the cutting tool of the present embodiment, in order to further improve the abrasion resistance, a DLC film may be coated on the blade ridge line and the blade constituent surface. Regarding the coating of the DLC film, a known film forming method such as a sputtering method or a plasma chemical vapor deposition (CVD) method can be used. If a filtered arc deposition (Filtered Arc Deposition) method is used, it can be expected DLC coating with fewer and smoother droplets. In addition, in order to form a DLC film with high hardness and high adhesion to the cutting tool, in this embodiment, there is a tendency to preferably reduce the flow rate of hydrogen-containing gas such as nitrogen and / or hydrocarbon introduced into the furnace , Coated with DLC film on one side. Here, in order to contain hydrogen on the surface of the DLC film on the hard reinforcement layer side, while removing the oxide film or contamination existing on the surface of the hard reinforcement layer, a mixed gas containing hydrogen may be used instead of introducing a gas containing hydrogen Gas bombard (gas bombard) treatment. The hydrogen mixed gas at this time is more preferably a mixed gas containing argon gas and hydrogen gas of 4% by mass or more with respect to the total mass of the mixed gas. [Example]

(Example 1) A cutting blade including a composite material in which WC was selected for the ceramic phase and Co was selected for the metal phase was prepared. The volume ratio of ceramic powder to metal powder of the composite material is 82:18. After grinding the portion of the cutting tool that becomes the blade constituent surface to Ra = 1.5 μm with a grinding tool, the blade constituent surface was polished to Ra = 0.005 μm by polishing and grinding using a diamond paste. Then, the cutting tool after polishing was immersed in nonaqueous water for 60 seconds to prepare a sample of the present invention in which Co (metal phase) was removed to form a hardened layer. Then, the obtained cutting tool was used to actually perform the cutting process, and the surface of the processed cutting tool was observed. The material to be processed is 13Cr stainless steel strip of SUS 420J2 system, and the total thickness of steel strips with different thicknesses ranging from 0.075 μm to 0.4 μm is cut by about 3500 m. The plate conveying speed of the steel strip at this time is about 60 m / min.

(Surface roughness measurement) With respect to the sample of the present invention example, the surface roughness of the blade-constituting surface was measured. For the measurement of surface roughness, a stylus roughness meter made by Tokyo Precision Co., Ltd. (surfcom) was used. The measurement conditions are evaluation length 4 mm, measurement speed 0.3 mm / s, threshold 0.8 mm, and filter type Gaussian. As a result of the measurement, it can be confirmed that the surface of the sample of the example of the present invention is smooth and has few convex portions. In particular, Rsk exhibits a large value of -1.8. This indicates that the concave portion in the roughness curve of the working surface is formed to a deep position, and it can be estimated that the hard reinforcement layer of the present invention is formed to a deep position.

[Table 1]

An enlarged photograph of both sides of the steel strip cut by the cutter of the present invention is shown in FIG. 4. It can be confirmed from FIG. 4 that even if a large number of cuts are made, the cut surface of the steel strip cut by the cutter of the example of the present invention shows a good cut surface without generating secondary shear surfaces or excessive burrs. .

(Example 2) The cutters of the examples of the present invention and the comparative example were prepared, and 13Cr stainless steel (plate thickness 0.1 mm) of the SUS420J2 system was cut at the same length. For the example of the present invention, the surface improvement cutter used in Example 1 was used, and the treatment of the present invention was not performed for the comparative example, and a cutter having a previous shape having a continuous blade ridge line as shown in FIG. 3 was used. The side of the steel strip after cutting was confirmed, and as a result, the maximum burr height at the start of cutting was 1 μm in the steel strip cut by the cutter of the comparative example, compared to 3 at the end of cutting The maximum burr height of μm. On the other hand, it can be confirmed that the maximum burr height at the end of the cutting of the steel strip cut using the cutter of the example of the present invention is also 1 μm, which is the same as that at the beginning of the steel strip. From the results, it can be confirmed that the cutter of the example of the present invention can perform better cutting than the comparative example, and can also perform further intermittent cutting.

(Example 3) Next, the material to be processed was changed to a Ni alloy, and the same length was cut with the cutter of the example of the present invention and the cutter of the comparative example, and poor performance was confirmed. Ni alloys are prone to burrs during cutting due to their softness, and the excessive burrs generated tend to break off and fall off, which tends to be in the form of metal powder. The generated amount of the metal powder is used as an index indicating the burr suppression effect of the cutter. The result of counting the abrasion powder is shown in Fig. 5. As shown in FIG. 5, it can be confirmed that the count of metal powder generated when using the cutter of the example of the present invention is reduced by about 35% compared to the count of metal powder generated when using the cutter of the comparative example. In particular, the number of counts of metal powder with a maximum diameter of 100 μm or more, which is likely to cause a decrease in product quality, also shows that the inventive example is about 50% of the comparative example, so that the cutting knife of the inventive example can be confirmed and compared The cutter of the example has fewer excessive burrs formed in the material to be processed, and can perform stable material cutting.

1. 1A, 1B‧‧‧cutting tool

2‧‧‧Ceramic phase

3‧‧‧Metal phase

4‧‧‧ Blade Ridge

5‧‧‧recess

5a‧‧‧Imaginary Blade Ridge

6, 7‧‧‧ blade formation surface

12‧‧‧Metal belt

13‧‧‧Metal strip

A‧‧‧part

FIG. 1 is a schematic diagram showing a metal tape cutting device of a cutter (Slitter) which is a cutting tool of the present embodiment. FIG. 2 is an enlarged schematic view of part A of the cutting tool of the present embodiment shown in FIG. 1. Fig. 3 is a schematic view of an enlarged part A of a cutting tool or a cutting tool before the surface improvement step. FIG. 4 is an enlarged photograph of both sides of a steel belt cut using the cutting tool of this embodiment. 5 is a graph showing the amount of abrasion powder generated during cutting of the cutting tool of the present invention and the cutting tool of the comparative example.

Claims (7)

A cutting tool, characterized by comprising a composite material containing a ceramic phase and a metal phase, wherein the cutting blade portion of the cutting tool has a cutting edge ridge line and a cutting edge configuration surface constituting the cutting edge ridge line, and the cutting edge configuration surface has a surface Part, the ceramic phase in the surface part protrudes from the composite material layer having the ceramic phase and the metal phase, and the ceramic phase in the surface part intermittently exists and lacks the metal phase, so The surface roughness of the surface portion satisfies: arithmetic average roughness Ra ≦ 0.1 μm, skewness Rsk ≦ −0.01. The cutting tool according to item 1 of the patent application, wherein the skewness Rsk ≦ -1.0 of the surface portion. The cutting tool according to claim 1 or claim 2, wherein the ceramic phase is WC or TiC, and the metal phase is at least one selected from Co, Ni, and Fe. The cutting tool according to any one of claims 1 to 3, wherein more than one layer of film or diamond-like carbon film is formed on the surface portion, and the film includes a group selected from Group 4a, A carbide, nitride, oxide, carbonitride, or boride of at least one of the element groups composed of Group 5a and Group 6a. The cutting tool according to any one of claims 1 to 4, wherein materials other than the metal phase are arranged between the ceramic phases on the surface portion. A method for manufacturing a cutting tool, characterized in that it is a method for manufacturing a cutting tool including a composite material containing a ceramic phase and a metal phase, wherein the blade portion of the cutting tool has a blade ridge line and a blade ridge line The blade forming surface, the manufacturing method of the cutting tool includes: a shape processing step of adjusting a portion of the tool base material that becomes the blade forming surface to an arithmetic average roughness Ra ≦ 0.1 μm by grinding, the tool base material including The composite material; and a surface improvement step, after the shape processing step, the portion of the tool base material adjusted to the arithmetic mean roughness Ra ≦ 0.1 μm that becomes the blade formation surface is etched to remove the blade The metal phase forming part of the surface is configured such that the blade forming surface has a surface portion in which the ceramic phase protrudes from the composite material layer including the ceramic phase and the metal phase, and the The ceramic phase intermittently exists in the surface portion and lacks the metal phase, and the surface roughness of the surface portion becomes Rsk ≦ -0.01. The method for manufacturing a cutting tool as described in item 6 of the patent application range, wherein the surface improvement step is wet etching using an acidic solution.