Surface coated cutting tools

Abstract

A surface-coated cutting tool wherein: 1) a coating layer includes a layer in which layer A and layer B are alternately laminated; 2) layer A is represented by Al1-aTiaN (0.30≤a≤0.70); 3) layer B is represented by Cr1-cM2cN (M2 is at least one of B and Si, 0.01≤c≤0.40 is satisfied); 4) the per-layer average thickness of each of layer A and layer B is 1-500 nm; 5) the average thickness of the layer in which layer A and layer B are alternately laminated is 0.3-7.0 μm; and 6) when the average thicknesses of layer A and layer B adjacent to each other are represented by TA and TB, respectively, 0.1≤TA / TB≤0.8 or 1.3≤TA / TB≤10.0 is satisfied.

Description

[Technical Field]

[0001] The present invention relates to a surface-coated cutting tool (hereinafter sometimes referred to as a coated tool). This application claims priority to Japanese Patent Application No. 2022-2531, filed on 11 January 2022. All provisions contained in said Japanese Patent Application are incorporated herein by reference. [Background technology]

[0002] Conventionally, coated tools have been known in which a coating layer is formed on the surface of a substrate such as a tungsten carbide (hereinafter referred to as WC)-based cemented carbide to improve the lifespan of cutting tools. Furthermore, various proposals have been made regarding the composition and structure of the coating layer in order to further improve the cutting performance of coated tools.

[0003] For example, Patent Document 1 contains (Ti x Al 1-x )(C y N 1-y A coated tool is described having a coating layer in which a first layer consisting of (where 0.20 ≤ x ≤ 0.60 and 0 ≤ y ≤ 0.5) and a second layer containing CrN are alternately laminated on the surface of a substrate, and the uppermost layer is composed of the first layer. The coating layer is said to have improved toughness without impairing wear resistance and to prevent chipping and peeling, and the coated tool showed sufficient durability in cutting tests using SKD61.

[0004] Furthermore, for example, Patent Document 2 describes a coated tool comprising a base layer in which TiAlN layers and mixed layers of TiAlN and CrBN are alternately laminated on the surface of a substrate, an intermediate layer consisting of a mixed layer of TiAlN and CrBN provided on the base layer, and a CrBN layer provided on the intermediate layer. This coated tool is said to have improved cutting performance and durability for non-ferrous workpieces such as iron-based or copper alloys, which have low hardness and are prone to welding, and for high-hardness steel materials such as tempered steel with a hardness of about 50 HRC. [Prior art documents] [Patent Documents]

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] The present invention has been made in view of the above circumstances and the above proposal, and an object thereof is to provide a coated tool having excellent durability even when used for high-speed cutting of difficult-to-machine materials such as Ti-based alloys.

Means for Solving the Problems

[0007] The surface-coated cutting tool according to an embodiment of the present invention has a substrate and a coating layer provided on the substrate. 1) The coating layer includes a layer in which layer A and layer B are alternately laminated. 2) The layer A is Al 1-a [[ID=​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​ (1) The layer in which the A layer and the B layer are alternately stacked has one or more C layers with an average thickness of 0.3 μm or more and 2.0 μm or less at any position therein, and the C layer is Al 1-d-e Ti d M3 e N(M3 is at least one of B and Si, 0.30≦d≦0.70, 0.00≦e≦0.30, d≠a).

[0009] Furthermore, as another embodiment, It has a substrate and a coating layer provided on the substrate, 1) The coating layer includes a layer in which layers A and B are alternately laminated, 2) The above layer A is Al 1-a-b Ti a M1 b N(M1 is at least one of B and Si, 0.30≦a≦0.70, 0.01≦b≦0.30), 3) The B layer is made of Cr 1-c M2 c N(M2 is at least one of B and Si, 0.01 ≤ c ≤ 0.40), 4) The average thickness of each layer of layer A and layer B is 1 nm or more and 500 nm or less, respectively. 5) The average thickness of the layer in which the A layer and the B layer are alternately stacked is 0.3 μm or more and 7.0 μm or less.

[0010] Furthermore, the surface cutting coating tool according to the above embodiment may satisfy one or more of the following (1) to (2).

[0011] (1) The layer in which the A layer and the B layer are alternately stacked has one or more C layers with an average thickness of 0.3 μm or more and 2.0 μm or less at any position therein, and the C layer is Al 1-d-e Ti d M3 e N(M3 is at least one of B and Si, 0.30≦d≦0.70, 0.00≦e≦0.30, d≠a and / or e≠b). (2) The average thickness of the adjoining A layer and B layer is T A , T B When this happens, 0.1≦TA / T B The value must be ≤ 10.0. [Effects of the Invention]

[0012] The aforementioned surface-coated cutting tool exhibits excellent durability even in high-speed cutting of difficult-to-machine materials such as Ti-based alloys. [Brief explanation of the drawing]

[0013] [Figure 1] This figure schematically shows a longitudinal cross-section (a cross-section perpendicular to the surface of the substrate) of a coating layer according to one embodiment of the present invention. [Figure 2] This figure schematically shows a longitudinal cross-section of a coating layer according to another embodiment of the present invention. [Modes for carrying out the invention]

[0014] The inventors have found that, for example, in high-speed cutting of Ti-based alloys (wet intermittent cutting with an end mill at a cutting speed of 80 m / min or more), the cutting edge has a large thermal and mechanical impact. load We diligently investigated coated tools that possess excellent cutting performance and durability over long-term use, even in cutting processes where the Ti-based alloy workpiece welds to the coated tool due to the action of [unspecified factor]. As a result, we obtained the following findings (1) to (3) regarding the reduction of welding caused by chemical reactions between the elements added to the Ti-based alloy and the coating layer.

[0015] (1) When the coating layer is a composite nitride containing Al and Ti, it is possible to reduce welding even with this composite nitride, but it is more preferable to include B and Si, which have low solid solution in Ti-based alloys, in this composite nitride to reduce welding.

[0016] (2) However, if the content of B and Si increases, hexagonal crystal grains are formed in the composite nitride containing Al and Ti, which reduces the hardness of the coating layer and prevents the coating layer from having sufficient wear resistance.

[0017] (3) Furthermore, even if hexagonal crystal grains are formed in the composite nitride containing Al and Ti, if a composite nitride mainly composed of Cr, which does not readily form hexagonal crystal grains, is laminated with the composite nitride containing Al and Ti, a decrease in the hardness of the coating layer can be prevented and sufficient wear resistance of the coating layer can be obtained.

[0018] The following describes in detail an embodiment of the coating tool of the present invention. In this specification and in the claims, when a numerical range is expressed as "L~M" (where L and M are both numerical values), the range includes an upper limit (M) and a lower limit (L). If a unit is specified only for the upper limit, the units of the upper limit (M) and the lower limit (L) are the same.

[0019] Furthermore, the term "surface of the substrate" as used in this specification and in the claims refers to the average line (straight line) of the roughness curve at the interface between the coating layer closest to the substrate surface and the substrate, calculated arithmetically. According to this method for calculating the average line, even if the substrate has a curved surface, if the tool diameter (diameter of the substrate) is sufficiently large relative to the thickness of the coating layer, the interface between the coating layer and the substrate can be treated as a plane, and thus the surface of the substrate can be determined in the same manner.

[0020] The high-speed cutting of difficult-to-machine materials referred to in the first and second embodiments described below includes, in addition to the wet intermittent cutting of Ti-based alloys with an end mill at a cutting speed of 80 m / min or more, as described above, wet continuous cutting of austenitic stainless steel with a turning insert at a cutting speed of 200 m / min or more, and side cutting of Ni-based alloys with an end mill at a cutting speed of 45 m / min or more.

[0021] The term "coating layer" refers to the layers present on the substrate surface, specifically the Ai layer, Bj layer, Ck layer (the Ck layer exists only in the second embodiment and not in the first embodiment), the underlayer, the upper layer, and any other layers that may occur incidentally.

[0022] Furthermore, in the following, Layer A, Layer B, and Layer C refer to the Ai, Bj, and C layers respectively, but the distinction between Layer A and Ai, Layer B and Bj, and Layer C and Ck is not strictly defined.

[0023] I. First Embodiment Figure 1 is a schematic diagram showing a longitudinal cross-section of the coating layer of a coated tool according to one embodiment of the present invention (in the case of an insert, a cross-section perpendicular to the surface of the substrate, ignoring minute irregularities on the surface of the substrate; in the case of a shaft tool such as an end mill or drill, a cross-section perpendicular to the central axis). In this embodiment, Ai layers (3) and Bj layers (4) are alternately stacked from the substrate (1) toward the surface of the coated tool, i.e., toward the surface of the coating layer (i=1~m, j=1~n, m and n are the number of layers, |mn|≦1). Hereinafter, the embodiment shown in Figure 1 will be referred to as the first embodiment and described accordingly. Note that although the base layer (6) and upper layer (7) are shown in Figure 1, these layers are not required.

[0024] 1. Alternating stacking of layers A and B. In this embodiment, as schematically shown in Figure 1, it is preferable that the substrate (1) is layered alternately with the Ai layer (3) and Bj layer (4) described below, extending toward the tool surface (surface of the coating layer). Note that the alternating layering (2) is also present in the white areas of Figure 1.

[0025] (1) A layer A Composition The average composition of layer A is Al 1-a-b Ti a M1 b It is preferable that N(M1 is at least one of B and Si, with 0.30 ≤ a ≤ 0.70 and 0.00 ≤ b ≤ 0.30). "M1 is at least one of B and Si" means that M1 = B, or M1 = Si, or M1 = B and Si.

[0026] The reasons for setting the values ​​of a and b within the aforementioned ranges are as follows: If the value of a is less than 0.30, the increase in Al content leads to the formation of hexagonal crystal grains, reducing the hardness of layer A and making it impossible to obtain sufficient wear resistance. On the other hand, if the value of a exceeds 0.70, the high-temperature hardness and high-temperature oxidation resistance of layer A decrease. It is more preferable that the value of a be between 0.40 and 0.65.

[0027] Furthermore, while a value of b of 0.00, i.e., the M1 component may not be present, a value of b of 0.01 or higher ensures a more reliable improvement in the welding resistance of layer A. On the other hand, if the value of b exceeds 0.30, layer A becomes brittle, and sufficient wear resistance cannot be obtained. A value of b of 0.03 or higher and 0.10 or lower is more preferable. When the value of b is 0.00, that is, when the M1 component is not included, the average thickness of layer A and layer B is set to T, as will be described later. A , T B When this happens, 0.1≦T A / T B ≤0.8 or 1.2 ≤T A / T B It is preferable that the value is ≤10.0.

[0028] Furthermore, according to one example of the manufacturing method described later, (Al 1-a-b Ti a M1 b The ratio of ) to N is manufactured to be 1:1, but sometimes there are unintentional cases where it is not 1:1. This is also true for other composite nitrides described below.

[0029] I. Average thickness The average thickness per layer of layer A, i.e., the average thickness of the Ai layer, is preferably 1 nm or more and 500 nm or less. The reason for this is that when the average thickness is less than 1 nm, the wear resistance and fracture resistance of the Ai layer are not sufficient, while when it exceeds 500 nm, the internal strain of the Bj layer increases due to lattice mismatch with the adjacent Bj layer, making the Bj layer prone to self-destruction. The average thickness of the Ai layer is more preferably 5 nm or more and 200 nm or less.

[0030] (2)B layer A Composition The average composition of layer B is Cr 1-c M2 c It is preferable that N(M2 is at least one of B and Si, 0.01 ≤ c ≤ 0.40). "M2 is at least one of B and Si" means that M2 = B, or M2 = Si, or M2 = B and Si.

[0031] The reason for setting the value of c within the aforementioned range is as follows: If the value of c is less than 0.01, the welding reduction provided by layer B is not fully realized, while if the value of c exceeds 0.40, layer B becomes brittle, and sufficient wear resistance cannot be obtained. Furthermore, it is more preferable that the value of c be between 0.05 and 0.20.

[0032] The B layer is a single phase, and the film is deposited in a way that prevents the deposition of nitrides such as Si3N4 and BN. These nitrides have low crystallinity and low hardness, so if they are deposited, they may become the starting point for fracture.

[0033] I. Average thickness The average thickness per layer of the B layer, i.e., the average thickness of the Bj layer, is preferably 1 nm or more and 500 nm or less. The reason for this is that when the average thickness is less than 1 nm, the Bj layer does not have sufficient resistance to welding, while when it exceeds 500 nm, the internal strain of the Bj layer increases, making it prone to self-destruction. The average thickness of the Bj layer is more preferably 5 nm or more and 200 nm or less.

[0034] (3) Alternating stacking of Ai and Bj layers It is preferable to have a layer in which A layers and B layers are stacked alternately, that is, Ai layers and Bj layers are stacked alternately in contact with each other. As mentioned above, the average thickness of the Ai layer and Bj layer is preferably 1 nm or more and 500 nm or less (the average thickness of the Ai layer and Bj layer may be the same or different), and the average thickness of the layer in which the Ai layer and Bj layer are stacked alternately is preferably 0.3 μm or more and 7.0 μm or less.

[0035] If the average thickness of the alternating layers of Ai and Bj is less than 0.3 μm, the alternating layers will not be able to obtain sufficient resistance to welding and abrasion. On the other hand, if it exceeds 7.0 μm, the internal strain will increase and it will be prone to self-destruction. It is more preferable that the average thickness be between 1.0 μm and 5.0 μm.

[0036] The average thickness of the adjacent Ai layer and Bj layer is T A , T B If that happens, When M1 is not present (b=0.00), 0.1≦T A / T B ≤0.8 or 1.2 ≤T A / T B Preferably, it is ≤10.0. When M1 is present (0.01 ≤ b ≤ 0.30), then 0.1 ≤ T A / T B It is more preferable that the value be ≤10.0. The reason is, When M1 is not present, T A / T B If the value is less than 0.1 or greater than 10.0, the alternating lamination may be prone to self-destruction due to lattice mismatch between the Ai and B layers. Furthermore, if the value is greater than 0.8 and less than 1.2, there is a risk that the A and B layers will become amorphous mixed layers, resulting in insufficient wear resistance. When M1 is present, T A / T B This is because if the value is less than 0.1 or greater than 10.0, the alternating stacking structure may be prone to self-destruction due to lattice mismatch between the Ai layer and the Bj layer.

[0037] In the first embodiment, T A / T B The calculation is performed as follows: For example, if a stack consists of five layers: Aj, Bi, Aj+1, Bi+1, and Aj+2, and this is the object of measurement, then when [Aj] represents the average thickness of the Aj layer and [Bi] represents the average thickness of the Bi layer, The average of [Aj] / [Bi], [Aj+1] / [Bi], [Aj+1] / [Bj+1], [Aj+2] / [Bi+1] is T A / T B Let's assume that.

[0038] In alternating stacking of Ai and Bj layers, the layer closest to the substrate can be either an Ai or a Bj layer, and the layer closest to the tool surface can also be either an Ai or a Bj layer. In alternating stacking of Ai and Bj layers, there are no particular restrictions on the total number of Ai and Bj layers (m+n), but it is more preferable that it be between 10 and 100.

[0039] ( 4 ) Other layers ( 4 -1) A layer whose existence is more desirable While the aforementioned problems can be sufficiently solved by alternating lamination of Ai and Bj layers (2), in addition to this alternating lamination, a base layer (6) may be selectively provided between the substrate (1) and this alternating lamination (2), and / or an upper layer (7) may be selectively provided on the tool surface side of this alternating lamination, as shown in Figure 1.

[0040] A. Substrate A base layer may be provided to more firmly bond the alternating layers of the substrate, Ai layer, and Bj layer. Examples of base layers include, but are not limited to, composite nitride layers of Al and Ti, composite nitride layers of Al, Ti, and Si, and composite nitride layers of Al and Cr (the composition of these layers is not limited to stoichiometric composition). The average thickness of this base layer may be, for example, 0.3 to 5.0 μm. The base layer may have the same composition as the Ai layer, and when the layer adjacent to the base layer is an Ai layer, the base layer and the Ai layer cannot be distinguished, and the base layer will be in contact with the Bj layer.

[0041] I. Upper layer The upper layer may be provided on the outermost surface (tool surface) of the alternating stacking of Ai and Bj layers on the tool surface side. A TiN layer is an example of the upper layer. Since the TiN layer has a golden hue, it can be used as an identification layer to distinguish whether a coated tool is unused or used by observing the change in the color tone of the coated tool surface. The average thickness of this TiN layer, which serves as the identification layer, can be, for example, 0.1 to 1.0 μm.

[0042] ( 4 -2) Layers that may occur by chance In this embodiment, the film is formed so that only layers A, B, the underlayer, and the upper layer exist. However, when changing the type of layer to be formed, pressure changes and temperature fluctuations may occur unintentionally within the film deposition apparatus, and layers with different compositions from these layers may be formed (unintentionally) by chance between them. These layers are referred to as layers that may occur by chance.

[0043] 2.Base (1)Material The substrate used in this embodiment can be any of the conventionally known substrate materials, as long as it does not hinder the achievement of the aforementioned objectives. For example, it is preferable to use any of the following: cemented carbide (WC-based cemented carbide, including those containing WC and Co, and further containing carbonitrides such as Ti, Ta, and Nb), cermet (for example, those mainly composed of TiC, TiN, and TiCN), ceramics (for example, titanium carbide, silicon carbide, silicon nitride, aluminum nitride, and aluminum oxide), cBN sintered body, or diamond sintered body.

[0044] (2) Shape The shape of the base material is not particularly restricted as long as it is a shape that can be used as a cutting tool; examples include the shape of an insert, the shape of an end mill, and the shape of a drill.

[0045] II. Second Embodiment Figure 2 is a schematic diagram showing a longitudinal cross-section of the coating layer of a coated tool according to another embodiment of the present invention. In this embodiment, the substrate (1) has a layer (8) in which one or more Ck layers (5) are inserted between alternating layers of contacting Ai layers (3) and Bj layers (4) toward the tool surface (surface of the coating layer) (i=1 to m, j=1 to n, m and n are the number of layers, 1 ≤ k ≤ p, p will be described later). Hereinafter, the embodiment shown in Figure 2 will be referred to as the second embodiment and described accordingly. Note that although the base layer (6) and upper layer (7) are shown in Figure 2, these layers are not required.

[0046] 1. A layer in which Ai layers and Bj layers are stacked alternately, with one or more Ck layers inserted at arbitrary positions. As schematically shown in Figure 2, the coating layer according to this embodiment is a layer in which Ai layers (3) and Bj layers (4) are alternately stacked from the substrate toward the tool surface (surface of the coating layer), with one or more Ck layers (5) inserted at arbitrary positions. 8 It is preferable that this is the case. Note that Ai layer (3), Bj layer (4), and Ck layer (5) are also present in the white areas of Figure 2. Here, the Ai layer and Bj layer are the same as those described in the first embodiment, so their description is omitted. There is no particular restriction on the upper limit (p) of the number of inserted Ck layers, but 15 is preferred, and 10 is more preferred. However, it is more preferable that even if layer C is present, there are regions where layers A and B each exist in a continuous sequence of five or more layers (for example, five layers of alternating layers such as A-B-A-B-A-B-A-B-A-B-A-B).

[0047] Even if a Ck layer is included, the average thickness of a layer in which one or more Ck layers are inserted at arbitrary positions in a layer in which Ai and Bj layers are stacked alternately is preferably 0.3 μm or more and 7.0 μm or less, similar to the average thickness of a layer in which Ai and Bj layers are stacked alternately. The reason is that if the average thickness of the coating layer is less than 0.3 μm, sufficient resistance to welding and abrasion cannot be obtained, while if it exceeds 7.0 μm, the internal strain increases and it becomes prone to self-destruction.

[0048] Furthermore, the average thickness of the adjacent Ai layer and Bj layer is T A , T B When T A / T B The preferred range is the same as in the first embodiment. Note T A / T B The calculation method is the same as in the first embodiment. That is, ignoring the presence of the Ck layer (assuming Ck does not exist), for example, if five layers are stacked and this is the target of measurement, then the stacked layers Aj, Bi, Aj+1, Bi+1, and Aj+2 are targeted.

[0049] (1)C layer A Composition The average composition of layer C is Al 1-d-e Ti d M3 e It is preferable that N(M3 is at least one of B and Si, 0.30≦d≦0.70, 0.00≦e≦0.30, d≠a and / or e≠b). "M3 is at least one of B and Si" means that M3 = B, or M3 = Si, or M3 = B and Si.

[0050] The reasons for setting the values ​​of d and e within the aforementioned ranges are as follows: If the value of d is less than 0.30, the increase in Al content leads to the formation of hexagonal crystal grains, reducing the hardness of the C layer and making it impossible to obtain sufficient wear resistance. On the other hand, if the value of d exceeds 0.70, the high-temperature hardness and high-temperature oxidation resistance of the C layer decrease. It is more preferable for the value of d to be between 0.40 and 0.65.

[0051] Furthermore, while a value of e of 0.00, meaning that the M3 component is not required, a value of e exceeding 0.00 (including the M3 component) more reliably improves the welding resistance of the C layer. On the other hand, if the value of e exceeds 0.30, the C layer becomes brittle, and sufficient wear resistance cannot be obtained. A value of e of 0.01 or higher and 0.10 or lower is more preferable.

[0052] I. Average thickness The average thickness per layer of the C layer, i.e., the average thickness of the Ck layer, is preferably 0.3 μm or more and 2.0 μm or less. The reason for this is that when the average thickness is less than 0.3 μm, the wear resistance of the Ck layer is insufficient, while when it exceeds 2.0 μm, the relative thickness of the Ck layer becomes large compared to a layer in which Ai and Bj layers are alternately laminated, and the welding resistance of a layer in which one or more Ck layers are inserted at arbitrary positions in a layer in which Ai and Bj layers are alternately laminated becomes insufficient. The average thickness of the Ck layer is more preferably 0.4 μm or more and 1.0 μm or less.

[0053] (2) Insertion location of the Ck layer In the alternating lamination of Ai layers and Bj layers, it is preferable that one or more Ck layers are inserted at arbitrary positions. Here, "inserted at arbitrary positions" means that the Ck layers are located between Ai layers, between Bj layers, between Ai layers and Bj layers, between the alternating lamination of Ai and Bj layers and the substrate, i.e., at a position adjacent to the substrate (between the lower layer if there is a lower layer, i.e., at a position adjacent to the lower layer), or at the outermost surface of the alternating lamination of Ai and Bj layers, i.e., the tool surface (between the Ai layer, Bj layer and upper layer if there is an upper layer). In other words, when a Ck layer is inserted, if we consider only the three adjacent layers, it will be one of the following: AiCkAi+1, BjCkBj+1, AiCkBj, BjCkAi, CkAiBj "on the substrate or underlayer if there is one", CkBjAi "on the substrate or underlayer if there is one", BjAiCk (Ck is in contact with the tool surface or the upper layer if there is one), or AiBjCk (Ck is in contact with the tool surface or the upper layer if there is one).

[0054] Furthermore, there are no particular restrictions on the number of layers in a layer in which Ai layers and Bj layers are stacked alternately and one or more Ck layers are inserted (the sum of the number of Ai layers, Bj layers, and Ck layers, i+j+k), but it is preferable that it be between 10 and 100. In this alternately stacked layer, there are no restrictions on the position where the C layer is inserted; for example, when there are three or more Ck layers, the number of Ai layers and Bj layers between adjacent Ck layers may be the same or different.

[0055] Furthermore, the layer closest to the substrate can be any of the Ai, Bj, or Ck layers, and the layer closest to the tool surface can also be any of the Ai, Bj, or Ck layers.

[0056] (3) Other layers Regarding the other layers, the description is the same as in the first embodiment, in which, with respect to the base layer, "alternating lamination of substrate, Ai layer, and Bj layer" is replaced with "a layer in which one or more Ck layers are inserted in an alternating lamination of substrate, Ai layer, and Bj layer"; with respect to the upper layer, "the tool surface side of the alternating lamination of Ai layer and Bj layer" is replaced with "the tool surface side of the layer in which one or more Ck layers are inserted in an alternating lamination of Ai layer and Bj layer"; and with respect to layers that may occur accidentally, "layers other than A, B, base layer, and upper layer" is replaced with "layers other than A, B, C, base layer, and upper layer".

[0057] 2.Base The substrate is the same as in the first embodiment.

[0058] III. Measurement Method A focused ion beam (FIB) system was used to cut a longitudinal section, and a scanning electron microscope (SEM) or transmission electron microscope (TEM) was used to examine at least five layers of each type of layer (T A / T BThe measurement is performed on five or more consecutive layers of the same type. For example, five consecutive layers such as A, B, A, B, A, B, A, B, A, B, A, B. If there are fewer than five layers of the same type within the coating layer, all such layers are measured. The thickness of each layer is measured at five locations (the observation magnification can be any magnification that allows for thickness measurement; 50,000 to 500,000 times for thickness measurement of layers A and B, and 10,000 to 10,000 times for layer C and the entire coating layer), and the average value is taken as the average thickness of each layer. Furthermore, the component composition of layers A, B, and C is measured at five locations for each layer using energy-dispersive X-ray spectroscopy (EDS) with SEM or TEM, Auger electron spectroscopy (AES), or electron probe microanalyzer (EPMA), and the average composition is calculated from the average value.

[0059] IV. Manufacturing method The coating layers of the first and second embodiments can be manufactured, for example, by the following PVD method. In the second embodiment, the process for forming layer C is performed, which is different from the first embodiment. In both the first and second embodiments, the process for forming the upper layer and the lower layer is not essential.

[0060] In other words, the Arc Ion Plating (AIP) apparatus is placed in a nitrogen atmosphere. To form the Ai layer, Al 100-a’-b’ Ti a’ M1 b’ (M1 is at least one of B and Si, 20 ≤ a' ≤ 80, 0 ≤ b' ≤ 40) target (AlTiM1 alloy target), For the formation of the Bj layer, Cr 100-c’ M2 c’ (M2 is at least one of B and Si, 1 ≤ c' ≤ 50) target (CrM2 alloy target), For the formation of the Ck layer, Al 100-d’-e’ Ti d’ M3 e’(M3 is a target of at least one of B and Si, 20≦d'≦80, 0≦e'≦40) (AlTiM3 alloy target), Furthermore, if necessary, For the formation of the underlying layer, a target made of alloys such as AlTi, AlTiSi, and AlCr is used, depending on the desired composite nitride layer. For the formation of the upper layer, for example, a Ti target, Prepare, Arc discharges are sequentially generated between these targets and the anode electrode to deposit a base layer, Ai layer, Bj layer, Ck layer, and upper layer of a predetermined average thickness. The composition of each target is expressed as an integer ratio of atoms.

[0061] The above description includes the following features. (Note 1) A surface-coated cutting tool having a substrate and a coating layer provided on the substrate, 1) The coating layer includes a layer in which layers A and B are alternately laminated, 2) The above layer A is Al 1-a-b Ti a N(0.30≦a≦0.70), 3) The B layer is made of Cr 1-c M2 c N(M2 is at least one of B and Si, 0.01 ≤ c ≤ 0.40), 4) The average thickness of each layer of layer A and layer B is 1 nm or more and 500 nm or less, respectively. 5) The average thickness of the layer in which the A and B layers are alternately stacked is 0.3 μm or more and 7.0 μm or less. 6) The average thickness of adjacent layers A and B is set to T A , T B When this happens, 0.1≦T A / T B ≤0.8 or 1.2 ≤T A / T B ≤ 10.0 A surface-coated cutting tool characterized by the following features. (Note 2) The surface-coated cutting tool according to appended claim 1, characterized in that there is a portion where the A layer and the B layer are successively present in at least 5 layers each. (Appended claim 3) The layer in which the A layer and the B layer are alternately laminated has, at any position therein, one or more C layers having an average thickness of 0.3 μm or more and 2.0 μm or less, and the C layer is Al 1-d-e Ti d M3 e N (M3 is at least one of B and Si, 0.30 ≦ d ≦ 0.70, 0.00 ≦ e ≦ 0.30, d ≠ a), the surface-coated cutting tool according to appended claim 1 or 2. (Appended claim 4) A surface-coated cutting tool having a substrate and a coating layer provided on the substrate, 1) The coating layer includes a layer in which the A layer and the B layer are alternately laminated, 2) The A layer is Al 1-a-b Ti a M1 b N (M1 is at least one of B and Si, 0.30 ≦ a ≦ 0.70, 0.01 ≦ b ≦ 0.30), 3) The B layer is Cr 1-c M2 c N (M2 is at least one of B and Si, 0.01 ≦ c ≦ 0.40), 4) The average thickness of each of the A layer and the B layer is 1 nm or more and 500 nm or less, 5) The average thickness of the layer in which the A layer and the B layer are alternately laminated is 0.3 μm or more and 7.0 μm or less A surface-coated cutting tool characterized by the above. (Appended claim 5) When the average thicknesses of the adjacent A layer and the B layer are T A , T B respectively, 0.1 ≦ T A / T B ≦ 10.0, the surface-coated cutting tool according to appended claim 4. (Appended claim 6) The layer in which the A layer and the B layer are alternately laminated has, at any position therein, one or more C layers having an average thickness of 0.3 μm or more and 2.0 μm or less, and the C layer is Al 1-d-e Ti dM3 e A surface-coated cutting tool as described in Appendix 3 or 4, characterized in that N(M3 is at least one of B and Si, 0.30≦d≦0.70, 0.00≦e≦0.30, d≠a and / or e≠b). (Note 7) A surface-coated cutting tool according to appendix 5 or 6, characterized in that there is a portion in which the A layer and the B layer each consist of five or more consecutive layers. (Note 8) A surface-coated cutting tool according to any one of the appendices 1 to 7, characterized in that it has a base layer directly above the substrate. (Note 9) A surface-coated cutting tool according to any one of the appendices 1 to 8, characterized in that the outermost surface of the coating layer is the upper layer. [Examples]

[0062] The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

[0063] (1) Manufacturing of the substrate As raw material powders, WC powder, TiC powder, VC powder, TaC powder, NbC powder, Cr3C2 powder, and Co powder were prepared and blended as shown in Table 1. Then, wax was added and the mixture was ball-milled in acetone for 24 hours, dried under reduced pressure, and then press-molded into compacts of a predetermined shape at a pressure of 98 MPa.

[0064] This compacted powder was vacuum sintered to form a sintered round bar for base formation with a diameter of 6 mm. Furthermore, end mill bases 1 to 4 made of WC-based cemented carbide were manufactured from the aforementioned sintered round bar by grinding, with four square cutting edges measuring 6 mm in diameter and 13 mm in length. Then, each of these substrates 1 to 4 was ultrasonically cleaned in acetone and dried.

[0065] (2) Manufacturing of the coating layer A substrate was mounted along the outer circumference of the rotating table of the AIP apparatus at a predetermined radial distance from the central axis. A target (cathode electrode) of AlTiM1 alloy of a predetermined composition, a target of CrM2 alloy of a predetermined composition, a target of AlTiM3 alloy of a predetermined composition, and further, targets of AlTi, AlTiSi, and AlCr alloys for forming the base layer, and a Ti target for forming the upper layer were arranged in the AIP apparatus.

[0066] After bombarding each of the substrates 1 to 4, the following (2-1) 1) to 5) are used to create an example of a coating tool corresponding to the first embodiment (Examples 1 to 24, 49 to 76) (Although it is written as "Examples 1-24, 49-76," it should be "Reference Examples 1-24, 49-76." Hereafter, including the table entries, it may be written as "Examples" instead of "Reference Examples.") Examples of coating tools corresponding to the second embodiment (Examples 25-48, 77-100) were manufactured by following steps 1') to 6') of (2-2). These examples are shown in Tables 12-27.

[0067] (2-1) Example of a coating tool corresponding to the first embodiment (Reference example) 1) Film formation of the underlying layer Several examples (Reference example) Next, the underlayer was formed using the following procedure. Nitrogen gas was introduced as a reaction gas into the AIP apparatus to create a nitrogen atmosphere of 3.5 Pa for the deposition of the underlayer, as shown in Table 11. The temperature of the substrate rotating on the rotary table was maintained at 480°C, and a DC bias voltage of -45V was applied. An arc discharge was generated between the AlTi, AlTiSi, and AlCr alloy targets and the anode electrode, corresponding to the composition of the underlayer to be deposited, thereby depositing the underlayer on the surface of the substrate. Note that in Tables 2-9, the target composition is expressed differently from the composition of layers A, B, and C, with the ratio of each atom shown as an integer with its sum equal to 100.

[0068] 2) Formation of the Ai layer Nitrogen gas was introduced as the reaction gas into the AIP apparatus, and an arc discharge was generated between the AlTiCrM1 alloy target and the anode electrode to deposit the Ai layer. The nitrogen atmosphere pressure, substrate temperature, and bias voltage were as shown in Tables 2, 3, 6, and 7, respectively.

[0069] 3) Formation of the Bj layer The Bj layer was deposited by generating an arc discharge between the CrM2X alloy target and the anode electrode. The nitrogen atmosphere pressure, substrate temperature, and bias voltage were as shown in Tables 2, 3, 6, and 7, respectively.

[0070] 4) Formation of a film in which Ai layers and Bj layers are alternately stacked. The film formation process described in 2) and 3) above is repeated a predetermined number of times, resulting in Tables 12, 13, 14, 15 and 20-23. Showing the AI ​​layer A layer was formed in which Bj layers were alternately stacked.

[0071] 5) Film formation of the upper layer Several examples (Reference example) Next, the upper layer was deposited using the following procedure. Nitrogen gas was introduced as a reaction gas into the AIP apparatus, and as shown in Table 11, the pressure of the nitrogen atmosphere for upper layer deposition was set to 4.0 Pa, the temperature of the substrate rotating on the rotary table was maintained at 500°C, and a bias voltage of -75V was applied to generate an arc discharge between the Ti target and the anode electrode corresponding to the composition of the upper layer to be deposited, thereby depositing the upper layer.

[0072] (2-2) Example of a coating tool corresponding to the second embodiment 1') Film formation of the underlying layer In some embodiments, a substrate layer was formed. The film formation conditions were the same as those described in 1) above.

[0073] 2') Deposition of the Ai layer The A layer was deposited under the deposition conditions corresponding to 2) of the first embodiment shown in Tables 4, 5, 8, and 9.

[0074] 3') Deposition of the Bj layer The B layer was deposited under the deposition conditions corresponding to 3) of the first embodiment shown in Tables 4, 5, 8, and 9.

[0075] 4') Formation of one or more Ck layers at any position within a layer in which Ai layers and Bj layers are alternately stacked. As mentioned above, the Ck layer was deposited so that it was inserted at arbitrary positions. The deposition conditions for Ck are described in 5'). In other words, when a Ck layer is to be provided adjacent to the base layer, the Ck layer is provided prior to the deposition of the Ai and Bj layers. When the Ck layer is to be inserted between Ai layers, between Bj layers, or between Ai and Bj layers, the deposition process described in 1) and 2) above is repeated a predetermined number of times to form a layer in which a predetermined number of Ai and Bj layers are stacked, and the Ck layer is formed on the outermost surface of this stacked layer. Then, a predetermined number of Ai and Bj layers are stacked alternately to form another layer, and the Ck layer is deposited again as needed. When a Ck layer is to be provided on the outermost surface of the alternating stack of Ai and Bj layers, the Ck layer is deposited after the completion of the alternating stacking of Ai and Bj layers. In this way, Tables 17, 19, 25, and 27 The number of Ck layers shown in the table were inserted at arbitrary positions within these alternatingly stacked layers. In the table, the insertion position of the C layer is the number of layers reached from the substrate (or the underlying layer if one exists) toward the surface of the coating tool, counting the layers adjacent to the substrate (or the underlying layer if one exists) as 1.

[0076] 5') Deposition of the Ck layer With nitrogen atmosphere pressure, substrate temperature, and bias voltage as shown in Tables 4, 5, 8, and 9, an arc discharge was generated between the AlTiM3 alloy target and the anode electrode, and a Ck layer with the composition and average thickness per layer shown in Tables 16, 17, 18, 19, and 24-27 was deposited.

[0077] 6') Film formation of the upper layer In some embodiments, an upper layer was deposited. The deposition conditions were the same as those described in 5) above.

[0078] (3) Comparative Example For comparison, each of the substrates 1 to 4 was ultrasonically cleaned in acetone, dried, and mounted along the outer circumference at a predetermined radial distance from the central axis on the rotating table of the AIP device, as in Examples 1 to 100. (Including examples 1-24 and 49-76) Similarly, bombardment treatment is performed, and the surface-coated inserts 1' to 16' of the comparative examples shown in Tables 28 and 29 (hereinafter referred to as Comparative Examples 1' to 16') are coated according to the film deposition conditions 1' to 16' shown in Table 10. (Comparative Examples 1' to 6' are reference comparative examples. Hereafter, including in the table, they may be referred to simply as comparative examples rather than reference comparative examples.) They manufactured each of them.

[0079] Examples 1 to 100 manufactured as described above (Including examples 1-24 and 49-76) and Comparative Examples 1'~16' (Including Reference Examples 1' to 6') Using the method described above, the average composition and average thickness were calculated (for samples with fewer than 5 C layers, the thickness was measured at 5 locations for all C layers).

[0080] Tables 12-29 show the measured and calculated values. "Overall average thickness (μm)" refers to the average thickness (μm) of the sum of the thicknesses of all Ai and Bj layers in the first embodiment, and the average thickness (μm) of the sum of the thicknesses of all Ai, Bj, and Ck layers in the second embodiment. In Tables 28 and 29, "-" indicates the absence of a value.

[0081] [Table 1]

[0082] [Table 2]

[0083] [Table 3]

[0084] [Table 4]

[0085] Table 5

[0086] Table 6

[0087] Table 7

[0088] Table 8

[0089] Table 9

[0090] Table 10

[0091] Table 11

[0092] Table 12

[0093] Table 13

[0094] Table 14

[0095] Table 15

[0096] Table 16

[0097] Table 17

[0098] Table 18

[0099] Table 19

[0100] Table 20

[0101] Table 21

[0102] Table 22

[0103] Table 23

[0104] Table 24

[0105] Table 25

[0106] [Table 26]

[0107] [Table 27]

[0108] [Table 28]

[0109] [Table 29]

[0110] Next, the above-mentioned Examples 1 to 100 (Including examples 1-24 and 49-76) and Comparative Examples 1'~16' (Including Reference Examples 1' to 6') For each of these tests, wet continuous cutting tests of Ti-based alloys were performed under the following cutting conditions, with the alloys fixed to a milling chuck using a fixed jig, and the wear width of the flank surface of the cutting edge was measured in units of 10 μm.

[0111] <Cutting conditions> Workpiece: Ti-6Al-4V plate with dimensions of 250mm x 100mm and a thickness of 60mm. Cutting speed: 100 m / min. Rotation speed: 5500 min -1 . Cutting depth: ae 0.3 mm, ap 6 mm Feed rate (per tooth): 0.08 mm / tooth Cutting length: 200 m, Cutting fluid: Water-soluble coolant Tables 21-28 show Examples 1-100, respectively. (Including examples 1-24 and 49-76) And comparative examples 1'~16' (Including Reference Examples 1' to 6') The results of the cutting test are shown.

[0112] [Table 30]

[0113] [Table 31]

[0114] [Table 32]

[0115] [Table 33]

[0116] [Table 34]

[0117] [Table 35]

[0118] [Table 36]

[0119] [Table 37]

[0120] In Table 30, the "*" in the "Comparative Example" column indicates the cutting distance (m) until the end of service life due to peeling, welding, chipping, wear, etc.

[0121] From the results shown in Tables 30-37, Examples 1-100 (Including examples 1-24 and 49-76) In all cases, even with high-speed cutting of Ti-based alloys, there is no peeling, welding, chipping, or wear of the coating layer, demonstrating excellent durability. In contrast, Comparative Examples 1'~16' (Including Reference Examples 1' to 6')In all cases, thermal and mechanical loads during high-speed cutting of Ti-based alloys caused peeling, welding, chipping, and wear of the coating layer, resulting in a short tool life.

[0122] The coated tool according to the present invention, in addition to Ti-based alloys, also uses Ni-based heat-resistant alloys and stainless steel, which also have high welding properties and large thermal and mechanical properties at the cutting edge. load Even when materials subjected to this process are subjected to cutting, excellent durability can be expected.

[0123] The embodiments disclosed herein are illustrative in all respects and are not restrictive. The scope of the present invention is indicated by the claims rather than by the embodiments described herein, and all modifications within the scope are intended to be included in the meaning of equivalences of the claims. [Explanation of symbols]

[0124] 1 Base 2. Alternating stacking of Ai and Bj layers 3 AI layer 4 Bj layer 5 Ck layer 6 Base layer 7 Upper layer 8. A layer in which Ck layers are inserted into alternating stacks of Ai and Bj layers.

Claims

1. A surface-coated cutting tool having a substrate and a coating layer provided on the substrate, 1) The coating layer includes a layer in which layers A and B are alternately laminated, 2) The above A layer is Al １－ａ Ti ａ N is (0.30 ≤ a ≤ 0.70), 3) The B layer is made of Cr １－ｃ M2 ｃ N (M2 is at least one of B and Si, 0.01 ≤ c ≤ 0.40), 4) The average thickness of each layer of layer A and layer B is 1 nm or more and 500 nm or less, respectively. 5) The average thickness of the layer in which the A and B layers are alternately stacked is 0.3 μm or more and 7.0 μm or less. 6) When the average thicknesses of the adjacent A layer and B layer are T Ａ , T Ｂ respectively, 0.1 ≦ T Ａ / T Ｂ ≦ 0.8 or 1.2 ≦ T Ａ / T Ｂ ≦ 10.0, and The layer formed by alternately stacking the aforementioned A layer and the B layer has at least one C layer with an average thickness of 0.3 μm or more and 2.0 μm or less at any position therein, and the C layer is Al 1-d-e Ti d M3 e N (M3 is at least one of B and Si, 0.30 ≤ d ≤ 0.70, 0.00 ≤ e ≤ 0.30, d ≠ a) A surface-coated cutting tool characterized by the following features.

2. A surface-coated cutting tool having a substrate and a coating layer provided on the substrate, 1) The coating layer includes a layer in which layers A and B are alternately laminated, 2) The above A layer is Al １－ａ－ｂ Ti ａ M1 ｂ N(M1 is at least one of B and Si, 0.30 ≤ a ≤ 0.70, 0.01 ≤ b ≤ 0.30), 3) The B layer is made of Cr １－ｃ M2 ｃ N (M2 is at least one of B and Si, 0.01 ≤ c ≤ 0.40), 4) The average thickness of each layer of layer A and layer B is 1 nm or more and 500 nm or less, respectively. 5) The average thickness of the layer in which the A and B layers are alternately stacked is 0.3 μm or more and 7.0 μm or less. The layer formed by alternately stacking the A layer and the B layer has at least one C layer with an average thickness of 0.3 μm or more and 2.0 μm or less at any position therein, and the C layer is Al 1-d-e Ti d M3 e N (M3 is at least one of B and Si, 0.30 ≤ d ≤ 0.70, 0.00 ≤ e ≤ 0.30, d ≠ a and / or e ≠ b) A surface-coated cutting tool characterized by the following features.

3. The average thickness of the adjacent A layer and B layer is set to T Ａ , T Ｂ When this happens, 0.1 ≤ T Ａ / T Ｂ The surface-coated cutting tool according to claim 2, characterized in that the coefficient is ≤ 10.0.

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