JP2010274334A - Surface-coated cutting tool and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface-coated cutting tool excellent in both of wear resistance and chipping resistance. <P>SOLUTION: This surface-coated cutting tool includes a base material and a coating layer, and in a cross section cut in a plane including a normal line with respect to a coating layer surface, when a straight line connecting a boundary point (a) between an area to which honing is applied on a rake surface of the base material and an area to which honing is not applied and a boundary point (b) between an area to which honing is applied on a flank thereof and an area to which honing is not applied is a straight line I, a straight line connecting a boundary point (c) between an area to which honing is applied on a rake surface of the coating layer and an area to which honing is not applied and a boundary point (d) between an area to which honing is applied on a flank thereof and an area to which honing is not applied is a straight line II, and an angle with which the straight line I and the straight line II cross is θ, the angle θ is within the range of 1°≤θ≤20°. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a surface-coated cutting tool including a base material and a coating layer formed on the surface of the base material, and a method for manufacturing the surface-coated cutting tool.

  Conventionally, a cutting tool made of a cemented carbide made of a WC-Co alloy or an alloy obtained by adding a carbonitride such as Ta and / or Ta and Nb to a WC-Co alloy or a WC-Co alloy has been used for cutting of general steel and castings. Has been. However, since the cutting edge of the cutting tool becomes a high temperature of 800 ° C. or higher during the cutting process, the cutting tool made of these cemented carbides is easily plastically deformed by the heat during the cutting process. As a result, the progress of flank wear tends to increase.

Therefore, in order to improve the cutting characteristics of the cutting tool at high temperature, the cemented carbide is used as a base material (base material), and the carbide, nitride, or carbonitride of group IVa metal of the periodic table is formed on the surface thereof. A surface-coated cutting tool in which a single layer of hard ceramics such as TiC, TiN, or TiCN, or Al ₂ O ₃ or a coating layer composed of a composite layer of these hard ceramics is used. For forming these coating layers, a chemical vapor deposition method such as a CVD (Chemical Vapor Deposition) method or a physical vapor deposition method such as an ion plating method or an ion sputtering method is used.

  Among the coating layers formed by these methods, particularly, the coating layer formed by chemical vapor deposition has very high adhesion strength with the base material of the cemented carbide, and has excellent wear resistance. In recent years, since the coating layer tends to become thicker due to the demand for higher speed and higher efficiency of cutting, the adhesion strength between the cemented carbide base material and the coating layer is important.

However, when the coating layer is formed by chemical vapor deposition, the temperature of the coating layer becomes a high temperature of about 1000 ° C. Therefore, when the coating layer is cooled to room temperature after forming the coating layer, the cemented carbide base material and the coating layer are formed. Tensile stress remains in the coating layer due to the difference in thermal expansion coefficient. As a result, when a crack is generated starting from the surface of the coating layer during cutting, the crack is propagated by tensile stress, and the coating layer is dropped or chipped. Specifically, the thermal expansion coefficient of the cemented carbide base material is about 5.1 × 10 ⁻⁶ K ⁻¹ , whereas the thermal expansion coefficient of the coating layer is about 9.2 × for TiN, for example. 10 ⁻⁶ K ⁻¹ , about 7.6 × 10 ⁻⁶ K ⁻¹ for TiC, and about 8.5 × 10 ⁻⁶ K ⁻¹ for Al ₂ O ₃ .

  The thickness of the coating layer of the surface-coated cutting tool currently in general use is in the range of about several μm to about tens of μm. Although the wear resistance increases as the coating layer thickness increases, For this reason, the thicker the coating layer, the higher the possibility that the tool will cause abnormal damage, resulting in reduced fracture resistance. In addition to the above, since the coating layer of the surface-coated cutting tool that is currently used generally grows depending on the surface shape of the substrate, the intermittent load during cutting is an interface between different coating layers on the cutting edge. In addition, since it acts on the interface between the coating layer and the substrate, cracks concentrate on the interface, and as a result, the coating layer is likely to fall off or chipping.

  Therefore, various techniques for improving the characteristics of such a coating layer have been proposed. For example, Japanese Patent Application Laid-Open No. 07-216549 (Patent Document 1) describes a technique for improving the cutting life of a cutting tool by eliminating cracks generated during cooling after forming an alumina layer.

Japanese Patent Laid-Open No. 05-057507 (Patent Document 2) discloses that a TiN or TiCN film is formed on the surface of a tool base made of a hard material as an outermost layer by chemical vapor deposition. After forming an Al ₂ O ₃ film as an adjacent inner layer, only the cutting edge of the tool is polished and the Al ₂ O ₃ film is exposed to improve chip welding resistance and impact resistance during cutting. It has been proposed as a technique for extending the tool life.

JP 07-216549 A JP 05-057507 A

  However, even with the tool disclosed in Patent Document 1, tensile stress still remains in the coating layer, so when cutting intermittently in high-speed machining and high-efficiency machining, it is still not fracture resistant. There was a problem of inferiority. In addition, since the outer shape of the coating layer and the base material at the edge of the cutting edge of the cutting tool is similar, intermittent loads during cutting are concentrated at the interface between the different coating layers and at the interface between the coating layer and the base material. Therefore, there was a problem that cracks occurred at the interface.

  In addition, the tool disclosed in Patent Document 2 focuses on the surface roughness of the cutting edge, and when intermittent loads during cutting are concentrated at the interface between the coating layers and the interface between the coating layer and the substrate. There was a problem that cracks occurred at the interface.

  Due to the problems as described above, there has been a problem that wear progresses non-uniformly due to dropping or chipping of the coating layer, and wear resistance decreases. These problems are problems in general for surface-coated cutting tools, but are particularly prominent problems in surface-coated cutting tools used for cutting such as milling and turning of grooved materials. In the surface-coated cutting tool used for the above-mentioned application, the chipping of the cutting edge is extremely likely to occur when an intermittent load is applied. Therefore, an object of the present invention is to provide a surface-coated cutting tool that is excellent in both wear resistance and fracture resistance.

  The surface-coated cutting tool of the present invention includes a base material and a coating layer formed on the surface of the base material, and the base material and the coating layer are each subjected to a honing treatment at the edge of the blade edge, In a cross section when the surface-coated cutting tool is cut along a plane including a normal line to the surface of the coating layer, a region where the honing treatment is performed on the rake face of the base material and a region where the honing treatment is not performed A straight line connecting a boundary point a and a boundary point b between a region where the honing process is performed on the flank of the base material and a region where the honing process is not performed is defined as a straight line I, and the rake surface of the coating layer The boundary point c between the region where the honing process is performed and the region where the honing process is not performed, and the region where the honing process is performed on the flank of the coating layer and the honing process are performed When the straight line connecting the boundary point d with the straight line is a straight line II and the angle at which the straight line I and the straight line II intersect is θ, the angle θ is in the range of 1 ° ≦ θ ≦ 20 °. It is characterized by.

  Here, the coating layer preferably has a thickness of 3 μm to 20 μm. The base material includes a plurality of hard phases made of a hard compound and a binder phase that bonds the hard phases, and the hard compound is an IVa group element (Ti, Zr, Hf, etc.) in the periodic table. Selected from the group consisting of carbides, nitrides, and carbonitrides of at least one element belonging to any one of the group elements Va, Vb (Nb, Ta, etc.) and Group VIa (Cr, Mo, W, etc.) It is preferable to consist of at least one compound and tungsten carbide. Alternatively, the hard compound is preferably tungsten carbide.

  On the other hand, the binder phase is preferably composed of at least one element selected from the group consisting of iron, cobalt, and nickel, and the coating layer is composed of a group IVa element, a group Va element, a group VIa in the periodic table. It is preferably composed of a compound comprising at least one element selected from the group consisting of element, aluminum, and silicon and at least one element selected from the group consisting of carbon, nitrogen, oxygen, and boron (B). .

  Moreover, this invention is a manufacturing method of the surface coating cutting tool in any one of said, Comprising: By masking a part by the side of the flank of the said coating layer, with respect to the blade edge ridgeline part of the said coating layer The present invention also relates to a method for manufacturing a surface-coated cutting tool including a step of performing a honing process.

  The surface-coated cutting tool of the present invention has excellent wear resistance and excellent fracture resistance by having the configuration as described above.

It is typical sectional drawing of the edge edge line part periphery of the surface coating cutting tool of this invention at the time of cut | disconnecting in the plane containing the normal line with respect to the surface of a coating layer. It is typical sectional drawing of the state which masked the surface coating cutting tool with the masking plate.

  Hereinafter, the present invention will be described in more detail. In the following description, the description may be made with reference to the drawings. In the drawings of the present invention, the same reference numerals denote the same or corresponding parts.

<Surface coated cutting tool>
The surface-coated cutting tool of the present invention includes a base material and a coating layer formed on the surface of the base material. The surface-coated cutting tool of the present invention having such a configuration is usefully used as a cutting edge-exchangeable cutting tip for drilling, end milling, milling, turning, crankshaft pin milling, and the like. Although not limited to these uses and shapes. The surface-coated cutting tool of the present invention is particularly suitable for cutting applications where intermittent loads are applied, such as milling and turning of grooved materials.

<Base material>
As the base material of the surface-coated cutting tool of the present invention, a conventionally known material known as such a cutting tool base material can be used without particular limitation. For example, cemented carbide (for example, WC base cemented carbide, including WC, including Co, or further including carbonitride such as Ti, Ta, Nb, etc.), cermet (TiC, TiN, TiCN, etc.) High-speed steel, ceramics (titanium carbide, silicon carbide, silicon nitride, aluminum nitride, aluminum oxide, and mixtures thereof), cubic boron nitride sintered body, diamond sintered body Etc. can be mentioned as examples of such a substrate.

In the present invention, among the base materials as described above, in particular, those having a structure including a plurality of hard phases (usually a matrix) made of a hard compound and a binder phase for bonding the hard phases together. Particularly preferred is a cemented carbide produced by sintering a powder of metal carbide which is a hard compound. Here, as such a hard compound, for example, a group consisting of carbide, nitride, and carbonitride of at least one element belonging to any of group IVa element, group Va element, and group VIa element of the periodic table It is preferable to consist of at least one compound selected from tungsten carbide. Alternatively, the hard compound is preferably only tungsten carbide. A specific example of at least one compound selected from the group consisting of carbides, nitrides, and carbonitrides of at least one element belonging to any of group IVa element, group Va element, and group VIa element of the periodic table Examples thereof include TiC, TiN, TaC, NbC, ZrCN, Cr ₃ C ₂ , ZrC, ZrN, TiCN, and the like. The hard phase may be composed of cermet or the like instead of the hard compound.

  The hard phase composed of the hard compound as described above is hard and has excellent wear resistance. In addition, the decrease in hardness at high temperatures is small. For this reason, it is suitable as a raw material for the substrate of the surface-coated cutting tool of the present invention.

  On the other hand, the binder phase has a function of binding the hard phases to each other, and is preferably composed of, for example, at least one element selected from the group consisting of iron-based metals, that is, iron, cobalt, and nickel. . A bonded phase of such an element is suitable because it has a property of strengthening the bond between the hard phases, particularly hard phases made of metal carbides. When the hard phase is made of cermet, the binder phase is particularly preferably cobalt, nickel, or an alloy of cobalt and nickel.

  In the present invention, when a cemented carbide is used as the base material, the effect of the present invention is exhibited even if such a cemented carbide contains an abnormal phase called free carbon or η phase in the structure. The base material used in the present invention may have a modified surface. For example, in the case of cemented carbide, a de-β layer may be formed on the surface, or in the case of cermet, a surface hardened layer may be formed, and even if the surface is modified in this way, The effect is shown.

<Coating layer>
The coating layer of the present invention includes a mode in which the entire surface of the substrate is coated and a mode in which the coating layer is not partially formed. The aspect which the lamination | stacking aspect of a part differs is also included. Moreover, it is preferable that the whole thickness of such a coating layer of this invention is 3 micrometers or more and 20 micrometers or less, More preferably, they are 5 micrometers or more and 18 micrometers or less. By setting the thickness of the coating layer to 3 μm or more, the effect of improving the wear resistance of the coating layer can be obtained, and the wear resistance improves as the thickness of the coating layer increases. On the other hand, the chipping resistance of the coating layer can be ensured by setting the thickness of the coating layer to 20 μm or less.

  As such a coating layer, a conventionally known coating layer can be used without any particular limitation, and is made of, for example, hard ceramics, particularly IVa group element, Va group element, VIa group element, aluminum, and silicon of the periodic table. It is preferably composed of a compound comprising at least one element selected from the group and at least one element selected from the group consisting of carbon, nitrogen, oxygen, and boron.

More specifically, as such a compound, carbide, nitride, carbon of at least one element selected from the group consisting of group IVa element, group Va element, group VIa element, aluminum and silicon in the periodic table And at least one compound selected from the group consisting of nitride, oxide, carbonate, carbonitride, boronitride, and borocarbonitride. More specifically, TiC, TiCN, TiN, TiSiN, TiSiCN, TiCNO, TiHfN, TiNbN, TiTaN, TiAlN, TiAlCrN, TiAlSiN, TiAlSiCrN, TiBN, TiAlBN, TiSiBN, TiBCN, TiAlBCN, TiSiBCN, CrN, AlN, AlCrN, Al 2 O 3, ZrN, ZrCN, ZrO 2, VN, It is mentioned such as TiO ₂ That.

  Such a coating layer may be a single layer or a composite layer composed of a plurality of layers. By forming such a coating layer on the substrate surface, the wear resistance is improved.

<Honing treatment and angle θ>
In the surface-coated cutting tool of the present invention, the base material and the coating layer described above are each subjected to a honing process at the edge of the cutting edge. Here, the edge of the cutting edge is the ridge where the rake face and the flank face intersect, and its peripheral part (if there is no ridge, the ridge line part is assumed to intersect the rake face and the flank face hypothetically. It includes a peripheral part) and refers to a part involved in cutting. Moreover, the site | part participating in cutting means the site | part where the temperature rises by the site | part which is actually in contact with a workpiece, and its peripheral site | part. The honing process refers to a process of chamfering or rounding (R) applying to the ridges because chipping or the like easily occurs when the edge ridge line portion forms a clear ridge. For this reason, although the blade edge ridge line portion is defined as described above, the edge is in a state of being chamfered or rounded (R), and there are few cases that actually show a clear edge.

  In the surface-coated cutting tool of the present invention, for example, as shown in FIG. 1, a normal line to the surface of the coating layer 2 (a straight line perpendicular to the surface when the coating layer 2 is assumed to be a plane or a curved surface) is provided. In the cross section when the surface-coated cutting tool 10 is cut by a plane including the boundary point a between the region 5 on which the honing treatment is performed on the rake face 3 of the substrate 1 and the region on which the honing treatment is not performed. A straight line connecting the boundary point b between the region 5 subjected to the honing process and the region not subjected to the honing process on the flank 4 of the substrate 1 is represented by a straight line I (shown by a broken line in FIG. 1). ) And the boundary point c between the region 6 subjected to the honing treatment on the rake face 3 of the coating layer 2 and the region not subjected to the honing treatment, and the honing on the flank 4 of the coating layer 2 A straight line connecting a boundary point d between the region 6 subjected to the process and the region not subjected to the honing process is defined as a straight line II (represented by a broken line in FIG. 1), and the straight line I and the straight line II When the angle at which the angle intersects is θ, the angle θ (the narrower angle) is in the range of 1 ° ≦ θ ≦ 20 °. The angle θ is more preferably in the range of 2 ° ≦ θ ≦ 10 °.

  In this way, by controlling the angle θ to the specific range as described above, it becomes possible to disperse the impact load acting on the edge of the cutting edge during the cutting process. It became possible to increase the adhesion strength of the. For this reason, it is possible to prevent the coating layer from falling off or chipping while improving the wear resistance by the coating layer, and thus the surface-coated cutting tool of the present invention is excellent in both wear resistance and chipping resistance. It will be a thing. When the angle θ exceeds 20 °, the covering function of the covering layer is not sufficiently exhibited, so that the wear resistance of the tool is lowered. On the other hand, when the angle θ is less than 1 °, a sufficient load distribution effect cannot be obtained, and chipping due to peeling of the coating layer is caused.

  In the above, each boundary point is determined by observing the cross section with a microscope. Usually, a point at which the straight line is bent with respect to the rake face and the flank face exhibiting a straight line in the cross section is defined as a boundary point.

  In addition, there are an infinite number of planes including the normal line because the plane is rotated about the normal line, and the angle θ is 1 ° ≦ θ ≦ 20 ° in any one of the planes. When it is difficult to specify the angle θ as in the case where it is out of the range, the center of the rake face of the coating layer surface as the normal line (if the through hole is formed in the center, the through hole Select the normal to the geometrical center when assuming that is not open, and include a ridge that intersects the two flank faces with this normal (including a hypothetical ridge) ) In the cross-section when cut by a plane including the same as the above (if there are a plurality of such cross-sections, it is determined by any one cross-section). This is because the edge of the cutting edge in the cross section is usually the central part of the cutting process.

  In addition, when the coating layer of the area | region where the honing process is performed becomes thin compared with the coating layer of the area | region where the honing process is not performed, and the coating layer is formed by two or more layers May reduce the number of stacked layers.

<Manufacturing method>
The manufacturing method of the surface coating cutting tool which concerns on this invention includes the process of performing a honing process with respect to the blade edge ridgeline part of the said coating layer by masking a part by the side of the flank of the said coating layer. The production method of the present invention can include other optional steps as long as such a step is included. For example, a step of preparing a base material, a step of performing a honing process on a cutting edge ridge line portion of the base material, The process of forming a coating layer etc. can be included in this order. And it is preferable to perform the process of performing a honing process with respect to the blade edge ridgeline part of a coating layer after these processes. Hereinafter, such a manufacturing method will be described in more detail.

  First, a base material is prepared. Then, a honing process is performed with respect to the edge edge line part of a base material using a brush or a plastic medium. Such a honing process may use a method in which fine particles collide with a substrate using shot peening. In addition, conventionally well-known conditions can be employ | adopted for various conditions of such a honing process.

  Next, a coating layer is formed on the surface of the substrate. The coating layer is formed on the substrate at a temperature of 800 ° C. or higher and 1100 ° C. or lower, for example, by placing the substrate in a chamber and using a vapor phase synthesis method such as a CVD method. In particular, the coating layer formed by such a CVD method is preferable because the adhesion strength with the base material is very high. In addition, this makes it possible to form a thick coating layer and improve wear resistance. The method for forming the coating layer in the present invention is not limited to such a CVD method. Instead of such a CVD method, for example, a physical vapor deposition method such as an ion plating method or an ion sputtering method is used. It may be used.

  Next, honing treatment is performed on the ridge line portion of the coating layer by masking a part of the flank side of the coating layer on the flank side of the coating layer formed as described above. Apply. In this case, such masking is performed as shown in FIG. 2 (a ridge (a hypothetical ridge where the two flank surfaces intersect with the normal to the center of the rake face on the surface of the coating layer with the surface-coated cutting tool masked). A sectional view when cutting them in a plane including a case where the cutting edge portion is included. (Note that the portion indicated by a broken line in the center of the drawing indicates a through hole.) As shown in FIG. And the flank face (assuming that it intersects (assumingly) an edge (assuming)) to 0.05 mm to 0.45 mm, preferably 0.1 mm to 0.4 mm (indicated by A in FIG. 2). Part) is covered with a masking plate 30 (preferably a metal plate) having a thickness (part indicated by B in FIG. 2) of 0.5 mm to 4 mm, preferably 0.7 mm to 3 mm. Applying a masking against the flank face side. Such masking is usually performed by covering the flank side of the surface-coated cutting tool with a masking plate in a band shape.

  Then, a honing process is performed on the edge portion of the edge of the coating layer masked as described above using a brush or a plastic medium. Such a honing process may use a method in which fine particles collide with the coating layer using shot peening. The masking medium is not limited to the masking plate. Moreover, conventionally well-known conditions can be employ | adopted for conditions other than the above of such a honing process.

  In this way, by masking a part of the coating layer on the flank side (that is, the remaining part excluding a certain range from the blade edge part), media such as brushes or plastic media wrap around the flank side during the honing process. Since this can be suppressed, the angle θ as described above can be formed. Such an angle θ can be adjusted by adjusting the range not masked by the masking plate and / or the thickness of the masking plate as described above.

  Note that the angle θ as described above cannot be formed when the masking as described above is not performed during the honing process of the edge of the edge of the coating layer. In such a case, the chipping resistance of the surface-coated cutting tool cannot be improved.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited to these.

<Example 1>
A cemented carbide base material having a cutting tool shape of JIS B 4120 (1998) CNMG120408 defined in JIS (Japanese Industrial Standard) was prepared as a base material. In addition, a total of 18 such substrates were prepared for each of the samples (A1 to A6) to be described later. The composition of this base material is composed of 87.0 wt% WC, 7.0 wt% Co, 3.0 wt% TiC, and 3.0 wt% NbC.

And the honing process was performed using the SiC brush etc. with respect to the blade edge ridgeline part of this base material. Next, a coating layer was formed on the surface of the substrate honed in this way. This coating layer is formed by a CVD method. First, TiN having a thickness of 0.5 μm is formed so as to be in contact with the surface of the substrate, and then MT (moderate temperature) -TiCN having a thickness of 7.0 μm is sequentially formed thereon. TiN having a thickness of 1.0 μm, Al ₂ O ₃ having a thickness of 7.0 μm, and TiN having a thickness of 1.5 μm were formed in this order.

  Subsequently, honing treatment is performed on the ridge line portion of the coating layer by masking a part of the flank side of the coating layer with respect to the flank side of the coating layer formed as described above. gave. Specifically, the flank face side of the coating layer was masked with the following masking plates (metal plates) having different thicknesses so that the range of 0.2 mm from the blade edge portion was not covered. That is, the masking plate (using SUS304 as a metal) has a thickness of 0.1 mm for sample A2, a thickness of 0.5 mm for sample A3, a thickness of 1.0 mm for sample A4, and a sample A5. The thickness was 4.0 mm, and the thickness of Sample A6 was 5.0 mm. On the other hand, the sample A1 was not masked. Such a honing process was performed using a brush from the surface of the edge of the edge of the coating layer to obtain a surface-coated cutting tool.

  Of each sample (surface-coated cutting tool) thus obtained, one for each sample, the normal to the surface of the coating layer (normal to the center of the rake face) and the corner (two flank surfaces intersect) The sample was cut along a plane including the edge to be machined, and the cross section was mechanically polished. And angle (theta) was measured by observing this cross section using an electron microscope. The results are shown in Table 1.

  On the other hand, wear resistance was evaluated under the following conditions using one sample for each sample among the samples not cut as described above. Further, the remaining samples were evaluated for chipping resistance (chipping resistance) under the following conditions using one sample for each sample. These results are also shown in Table 1 below.

<Evaluation of wear resistance>
Work material: SCM435 (JIS)
Cutting speed: 270 m / min.
Feed: 0.3 mm / rev.
Cutting depth: 1.5mm
Cutting oil: wet cutting time: 20 min.
Evaluation: Measuring the flank wear amount (the smaller the value, the better the wear resistance)
<Evaluation of fracture resistance>
Work material: SCM435 (JIS) grooved material cutting speed: 330 m / min.
Feed: 0.25 mm / rev.
Cutting depth: 1.5mm
Cutting oil: Wet evaluation: Time until chipping or chipping (the longer the better the chipping resistance)

  In Table 1, samples A3 to A5 are examples, and samples A1, A2 and A6 are comparative examples. As can be seen from Table 1, the samples A3 to A5, which are examples of the present invention, obtained the same flank wear amount results as the samples A1 and A2, while the chipping or The time until loss ("shock time" in Table 1) is dramatically increased. On the other hand, Sample A6 had a time until chipping or chipping almost equivalent to Samples A3 to A5, but the flank wear amount was larger than those of these Examples. Therefore, from the above results, it was confirmed that the surface-coated cutting tool of the present invention was excellent in both wear resistance and fracture resistance.

<Example 2>
The same substrate as that used in Example 1 was prepared. In addition, a total of nine such base materials were prepared for each of the samples (B1 to B3) described later.

And the honing process was performed using the SiC brush etc. with respect to the blade edge ridgeline part of this base material. Next, a coating layer was formed on the surface of the substrate honed in this way. This coating layer is formed by a CVD method. First, TiN having a thickness of 0.5 μm is formed so as to be in contact with the surface of the substrate, and then MT (moderate temperature) -TiCN having a thickness of 10.0 μm is sequentially formed thereon. TiBN having a thickness of 1.0 μm, Al ₂ O ₃ having a thickness of 6.0 μm, and TiN having a thickness of 1.5 μm were formed in this order.

  Subsequently, honing treatment is performed on the ridge line portion of the coating layer by masking a part of the flank side of the coating layer with respect to the flank side of the coating layer formed as described above. gave. Specifically, a masking plate having a thickness of 1 mm (a metal plate (using SUS304 as a metal)) is used so that only a range in which the distance from the blade edge portion is as follows is not covered. Masking was applied to the flank side of the coating layer. That is, the distance from the blade edge portion (see “Masking position” column in Table 2) is 0 mm for sample B1, 0.25 mm for sample B2, and 0.50 mm for sample B3, respectively. Masking was performed so as not to cover only (the sample B1 was covered with the entire flank by the masking plate). In addition, such honing process was performed using the brush from the surface of the blade edge ridgeline part of the coating layer, and the surface coating cutting tool was obtained.

  Of each sample (surface-coated cutting tool) thus obtained, one for each sample, the normal to the surface of the coating layer (normal to the center of the rake face) and the corner (two flank surfaces intersect) The sample was cut along a plane including the edge to be machined, and the cross section was mechanically polished. And angle (theta) was measured by observing this cross section using an electron microscope. The results are shown in Table 2.

  On the other hand, wear resistance was evaluated under the same conditions as in Example 1 using one sample for each sample among the samples not cut as described above. Furthermore, the remaining samples were evaluated for chipping resistance (chipping resistance) under the same conditions as in Example 1 using one sample for each sample. These results are also shown in Table 2 below.

  In Table 2, sample B2 is an example, and samples B1 and B3 are comparative examples. As is clear from Table 2, the sample B2 which is an example of the present invention has a flank wear amount result equivalent to that of the sample B3, while the time until chipping or chipping is shorter than that of the sample B3 ( The “impact time” in Table 2) has been dramatically increased. On the other hand, although the sample B1 has almost the same time until chipping or chipping as the sample B2, the flank wear amount is larger than that of this example. Therefore, from the above results, it was confirmed that the surface-coated cutting tool of the present invention was excellent in both wear resistance and fracture resistance.

  Although the embodiments and examples of the present invention have been described as described above, it is also planned from the beginning to appropriately combine the configurations of the above-described embodiments and examples.

  It should be understood that the embodiments and examples disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  DESCRIPTION OF SYMBOLS 1 Base material, 2 Coating layer, 3 Rake face, 4 Relief face, 5,6 The area | region where the honing process is performed, 10 Surface coating cutting tool, 20 Cutting edge part, 30 Masking plate.

Claims (7)

A surface-coated cutting tool comprising a substrate and a coating layer formed on the substrate surface,
The base material and the coating layer are each subjected to a honing process at the edge portion of the blade edge,
In a cross section when the surface-coated cutting tool is cut at a plane including a normal line to the surface of the coating layer, a region where the honing treatment is performed on the rake face of the base material and a region where the honing treatment is not performed A straight line connecting a boundary point a and a boundary point b between a region where the honing process is performed on the flank of the base material and a region where the honing process is not performed is defined as a straight line I, and the rake surface of the coating layer A boundary point c between a region subjected to honing processing and a region not subjected to honing processing, and a region subjected to honing processing and a region not subjected to honing processing on the flank of the covering layer. When a straight line connecting the boundary point d is a straight line II, and an angle between the straight line I and the straight line II is θ,
The angle θ is a surface-coated cutting tool in a range of 1 ° ≦ θ ≦ 20 °.   The surface-coated cutting tool according to claim 1, wherein the coating layer has a thickness of 3 μm to 20 μm. The base material includes a plurality of hard phases made of a hard compound and a binder phase that bonds the hard phases;
The hard compound is at least one compound selected from the group consisting of carbides, nitrides, and carbonitrides of at least one element belonging to any of group IVa element, group Va element, and group VIa element of the periodic table The surface-coated cutting tool according to claim 1 or 2, comprising tungsten carbide. The base material includes a plurality of hard phases made of a hard compound and a binder phase that bonds the hard phases;
The surface-coated cutting tool according to claim 1, wherein the hard compound is tungsten carbide.   The surface-coated cutting tool according to claim 3 or 4, wherein the binder phase is composed of at least one element selected from the group consisting of iron, cobalt, and nickel.   The covering layer is selected from the group consisting of at least one element selected from the group consisting of group IVa elements, group Va elements, group VIa elements, aluminum, and silicon in the periodic table, and carbon, nitrogen, oxygen, and boron. The surface-coated cutting tool according to any one of claims 1 to 5, wherein the surface-coated cutting tool is composed of a compound composed of at least one element. It is a manufacturing method of the surface covering cutting tool in any one of Claims 1-6,
The manufacturing method of the surface coating cutting tool including the process of performing a honing process with respect to the blade edge ridgeline part of the said coating layer by masking a part by the side of the flank of the said coating layer.

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