JP2016185589A - Surface-coated cutting tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coated tool for exhibiting excellent abrasion resistance and defect resistance even when cutting a titanium alloy, a heat resistant alloy, stainless steel or the like under a high speed cutting condition of causing high heat generation.SOLUTION: In a surface-coated cutting tool, a backing layer is composed of an alternate lamination layer of a thin layer C for satisfying (AlTi)(ON) (a is 0.25≤a≤0.75, and b is 0.50≤b≤0.9 in the atomic ratio) and a thin layer D for satisfying (AlTi)N (g is 0.25≤g≤0.75 in the atomic ratio), and an intermediate layer satisfies (AlTi)N (g is 0.25≤g≤0.75 in the atomic ratio), and an upper layer is composed of an alternate lamination ayer of a thin layer A for satisfying (AlCr)(ON) (c and d are 0.20≤c≤0.60, 0.01≤d≤0.50 in the atomic ratio) and a thin layer B for satisfying (AlMn)(ON) (e and f are 0.10≤e≤0.50, 0.01≤f≤0.50 in the atomic ratio).SELECTED DRAWING: Figure 3

Description

  The present invention relates to a surface-coated cutting tool (hereinafter referred to as a coated tool), and more specifically, for example, a work material that is accompanied by high heat generation such as titanium alloy, heat-resistant alloy, and stainless steel and that has a remarkable weldability to a cutting blade. The present invention relates to a coated tool that exhibits high-temperature stability, heat resistance, wear resistance, and welding resistance with excellent hard coating layers when high-speed cutting is performed.

  In general, coated tools are used for turning and planing of work materials such as various types of steel and cast iron, inserts that can be used detachably attached to the tip of a cutting tool, drilling processing of work materials, etc. There are drills, miniature drills, solid type end mills used for chamfering, grooving, shoulder processing, etc. of the work material, etc. Also, inserts are detachably attached and cutting is performed in the same way as solid type end mills Insert type end mill tools are known.

  In recent years, there is a high demand for higher efficiency in cutting metal materials, and it is required to increase the cutting speed. For this reason, it is requested | required that a wear resistance and a fracture | rupture resistance should be improved with respect to the film which coat | covers the tool base | substrate surface of a cutting tool.

Patent Document 1 discloses a hard coating layer based on an aluminum oxide, and Al _1-x M _x (O _1-Y N _Y ) _z (0 ≦ X ≦ 0.5, 0 <Y ≦ 0. 4, Z> 0), and M in this composition is at least one element selected from Ti, Zr, V, Nb, Mo, W, Y, Mg, Si, and B An AlM (ON) hard coating layer is disclosed. Further, the same document discloses that such a hard coating layer is excellent in wear resistance and heat resistance, and can be formed at a substrate temperature of 1000 ° C. or lower, specifically 400 to 600 ° C. Yes.

  Further, Patent Document 2 forms a film on a tool base of a coated tool, and this film is a composite in which one or more first super multi-layer films and one or more second super multi-layer films are alternately laminated. Including a super multi-layer film, wherein the first super multi-layer film is formed by alternately laminating one or more layers each of A1 layers and B layers, and the second super multi-layer film comprises A2 layers and C layers, respectively. It is configured by alternately laminating one or more layers, the A1 layer and the A2 layer are each composed of TiN, TiCN, TiAlN, or TiAlCN, the B layer is composed of TiSiN or TiSiCN, and the C layer Discloses providing a coated tool having a laminated hard coating layer with reduced brittleness problems while maintaining wear resistance and heat resistance by being composed of AlCrN or AlCrCN.

  Further, as another conventional coated tool, for example, an arc ion plating apparatus, which is one of physical vapor deposition apparatuses shown schematically in FIG. 2, is loaded with a tool base, and the tool base is heated to 450 ° C. with a heater. While being heated to a temperature, an arc discharge is generated between the anode electrode and a cathode electrode (evaporation source) on which an Al—Cr alloy having a predetermined composition is set under the condition of current: 100 A and simultaneously reacts in the apparatus. Nitrogen gas is introduced as a gas to form a nitrogen atmosphere. On the other hand, by evaporating evaporated particles on the surface of the tool base under the condition that a bias voltage of −200 V is applied (Al, Cr, for example) ) It is also known that a hard coating layer composed of an N layer is formed (see, for example, Patent Document 3).

JP 2010-236092 A International Publication No. 2008/146727 JP 2000-271699 A

  However, the automation of cutting machines in recent years has been remarkable. On the other hand, there is a strong demand for labor saving, energy saving, and cost reduction for cutting, and as a result, cutting tools have as much influence on the type of work material as possible. However, in a conventional coated tool using a coating layer composed of an (Al, Cr) N layer, there is a tendency to be versatile, that is, a cutting tool capable of cutting as many grades as possible. Is used for cutting at normal cutting speeds of work materials such as steel and cast iron, but titanium alloys, heat-resistant alloys, stainless steel, etc. are accompanied by high heat generation and are applied to the cutting edge. When cutting under high-speed cutting conditions with remarkable impact and weldability, the (Al, Cr) N layer is a hard film, but the film itself may collapse or peel due to its hardness and high residual stress. Questions There are, as a result, occurs rapidly increased in defects in the cutting edge (small chipping), which is at present, leading to a relatively short time service life due.

For example, according to Patent Document 1, although it is possible to improve the wear resistance and heat resistance to some extent, since the problem of such an AlM (ON) hard coating layer shows brittleness, impact during cutting, etc. This causes a problem that the coating itself is broken or peeled off.
Further, even with the hard coating layer of Patent Document 2, even under severe cutting conditions, the individual coatings constituting the laminated structure cannot be sufficiently prevented from being broken or peeled, resulting in a sufficient hard coating. In some cases, the wear resistance of the entire layer could not be obtained.
Therefore, the technical problem to be solved by the present invention, that is, the object of the present invention is to have excellent heat resistance even when cutting titanium alloy, heat-resistant alloy, stainless steel, etc. under high-speed cutting conditions with high heat generation, An object of the present invention is to provide a coated tool that exhibits wear resistance and welding resistance and exhibits excellent cutting performance over a long period of time.

  In view of the above, the inventors of the present invention cut a workpiece with high-temperature heat generation, particularly titanium alloy, heat-resistant alloy, stainless steel, and the like, which has remarkable weldability to the cutting edge under high-speed cutting conditions. In this case, intensive research was conducted to develop a coated tool having a hard coating layer with excellent heat resistance, wear resistance and welding resistance.

As a result, the following new findings were obtained.
(1) The (Al, Cr) (ON) layer has wear resistance, and heat resistance can be improved by containing a predetermined amount of oxygen.
(2) The (Al, Mn) (ON) layer is a very stable substance of Mn oxide itself, and when introduced into the Al oxide, it improves the high-temperature stability of the Al oxide. There is an effect. Furthermore, by further developing this to form a composite oxynitride of Al and Mn, the wear resistance is improved as compared with each oxide. As a result, it exhibits excellent heat resistance, wear resistance, and welding resistance to difficult-to-cut materials that easily generate heat during cutting.
(3) However, when the above-described (Al, Cr) (ON) layer and (Al, Mn) (ON) layer are respectively used alone, the wear resistance can be obtained only by the (Al, Cr) (ON) layer. Even if it can be secured, heat resistance is poor. Conversely, when an (Al, Mn) (ON) layer is used alone, it is practically used as a hard coating layer for cutting tools with poor wear resistance even if heat resistance can be secured. Not right. Further, if it is attempted to increase wear resistance by increasing the thickness of each layer, chipping is likely to occur due to the residual compressive stress generated in the layer, and the cutting performance cannot be maintained over a long period of time.

  Based on such knowledge, the present invention provides an underlayer consisting of alternating layers of thin layers C composed of (Al, Ti) N layers and thin layers D composed of (Al, Ti) (ON) layers, and C layers. An intermediate layer composed of a thicker (Al, Ti) (ON) layer, a thin layer A composed of an (Al, Cr) (ON) layer, and a thin layer B composed of an (Al, Mn) (ON) layer In a coated tool in which an upper layer composed of alternating layers is coated, the average layer thickness of each layer, the composition of thin layers C and D, the composition of thin layers A and B, the total layer thickness of the entire hard coating layer, etc. This is obtained as a result of detailed analysis of the relationship with the cutting performance, and specifically comprises the following configuration.

The present invention has been made based on the research results,
In a surface-coated cutting tool formed by forming a hard coating layer on the surface of a tool base composed of tungsten carbide-based cemented carbide or titanium carbonitride-based cermet,
The hard coating layer is
(A) an underlayer having an alternating layered structure of thin layers C and D formed on the surface of the tool base, wherein the total average layer thickness of the alternating layers is 0.5 to 5.0 μm;
(B) having an average layer thickness of 0.1 to 1.0 μm formed on the surface of the underlayer, and
Composition formula: (Al _1-a Ti _a ) (O _1-b N _b ) (where a represents the content ratio of Ti in the total amount of Al and Ti, and the atomic ratio is 0.25 ≦ a ≦ B represents the content ratio of N in the total amount of O and N, and an intermediate layer satisfying an atomic ratio of 0.50 ≦ b ≦ 0.9);
(C) It consists of an alternating layered structure of thin layers A and thin layers B formed on the surface of the intermediate layer, consisting of an upper layer having a total average layer thickness of 0.5 to 5.0 μm.
(D) The thin layer C has an average layer thickness of 1 to 50 nm, and
Composition formula: (Al _1-a Ti _a ) (O _1-b N _b ) (where a represents the content ratio of Ti in the total amount of Al and Ti, and the atomic ratio is 0.25 ≦ a ≦ Further, b represents the content ratio of N in the total amount of O and N, and the composite nitridation of Al and Ti satisfying the atomic ratio of 0.50 ≦ b ≦ 0.9) Consists of layers
(E) the thin layer D has an average layer thickness of 1 to 50 nm, and
Composition formula: (Al _1-g Ti _g ) N (where g represents the content ratio of Ti in the total amount of Al and Ti, and the atomic ratio is 0.25 ≦ g ≦ 0.75) It consists of a composite nitride layer of Al and Ti that is satisfactory,
(F) The thin layer A has an average layer thickness of 1 to 50 nm, and
Composition formula: (Al _1-c Cr _c ) (O _1-d N _d ) (where c represents the content ratio of Cr in the total amount of Al and Cr, and the atomic ratio is 0.20 ≦ c ≦ In addition, d represents the content ratio of N in the total amount of O and N, and the composite nitridation of Al and Cr satisfying the atomic ratio of 0.01 ≦ d ≦ 0.50) Consists of layers
(G) The thin layer B has an average layer thickness of 1 to 50 nm, and
Composition formula: (Al _1-e Mn _e ) (O _1-f N _f ) (where e represents the content ratio of Mn in the total amount of Al and Mn, and the atomic ratio is 0.10 ≦ e ≦ In addition, f indicates the content ratio of N in the total amount of O and N, and the composite nitridation of Al and Mn satisfying the atomic ratio of 0.01 ≦ f ≦ 0.50) Consists of layers
(H) The base layer and the upper layer are thicker than the intermediate layer, and the total average thickness of the hard coating layer is 1.1 to 11.0 μm. Surface coated cutting tool. "
It is characterized by.

Next, the reason why the numerical values of the constituent layers of the hard coating layer of the coated tool of the present invention are limited as described above will be described.
Composition of the (Al, Ti) (ON) layer constituting the thin layer C of the underlayer:
The (Al, Ti) (ON) layer, which is a thin layer C having an average layer thickness of 1 to 50 nm formed between the tool base and the intermediate layer, forms an alternate laminated (nano laminated) structure together with the thin layer D. Thus, the adhesion strength of the hard coating layer to the tool base is increased and the occurrence of delamination is prevented.
The Ti component, which is a component of the C layer, provides excellent high-temperature strength, and the Al component supplements high-temperature hardness and heat resistance. However, when the thin layer C is represented by the composition formula: (Al _1-a Ti _a ) (O _1-b N _b ), the value of a indicating the content ratio of Ti in the total amount of Al and Ti ( If the atomic ratio is less than 0.25, high temperature strength cannot be ensured, and abnormal damage is likely to occur at the boundary portion of the cutting edge, and defects are likely to occur. On the other hand, the value of a indicating the Ti content is 0. If it exceeds .75, the Al content will be relatively reduced, and not only the high-temperature hardness required for high-speed cutting will be secured, but also the wear resistance will be reduced, and chipping will be prevented. Since it becomes difficult, the value of a is set to 0.25 to 0.75.
The value (atomic ratio) of b indicating the content ratio of N in the total amount of O and N is the content ratio of the component N essential for increasing the hardness of the (Al, Ti) (ON) layer. In order to make the effect sufficient, it is necessary that the content ratio of N occupies more than half of the total amount of O and N. However, if the value of b exceeds 0.9, the content ratio of O becomes relatively less than 0.1, and the effect of improving heat resistance by the addition of O is not sufficiently achieved. Therefore, the value of b is set to 0.50 to 0.9.

Composition of the (Al, Ti) N layer constituting the thin layer D of the underlayer:
Since the thin layer A and the thin layer B, which will be described later, according to the present invention are chemically stable, it is difficult to obtain high adhesion to the surface of the tool base, so it is necessary to provide an underlayer and an intermediate layer between the tool base. There is. As the underlayer, a nitride thin layer D made of (Al, Ti) N is preferably used from the viewpoint of adhesion to the tool base surface, while from the viewpoint of adhesion to the intermediate layer, A thin layer C of oxynitride made of (Al, Ti) (ON) is preferred. Therefore, in the present invention, by forming the base layer as an alternate stack (nano stack) of the thin layer C and the thin layer D, the strength of the base layer itself is increased, and at the same time, the adhesion strength between the tool base and the intermediate layer is increased. . When the thin layer D is expressed by the composition formula: (Al _1-g Ti _g ) N, when the value of g is 0.25 ≦ g ≦ 0.75 in terms of atomic ratio, Excellent thermal stability and excellent wear resistance during high-speed cutting.
Therefore, as the thin layer D, the composition formula: (Al _1-g Ti _g ) N (where g represents the content ratio of Ti in the total amount of Al and Ti, and the atomic ratio is 0.25 ≦ g The composite nitride layer of Al and Ti satisfying (≦ 0.75).

Composition of (Al, Ti) (ON) layer constituting the intermediate layer:
The (Al, Ti) (ON) layer, which is an intermediate layer having an average layer thickness of 0.1 to 1.0 μm formed between the base layer and the upper layer, acts to increase the adhesion strength between the lower layer and the upper layer. .
Since the composition formula of the (Al, Ti) (ON) layer of the intermediate layer is the same as the composition formula of the thin layer C of the underlayer, the adhesion strength with the underlayer is high. And in this invention, the adhesive strength with an upper layer can be further improved by forming the layer thickness of an intermediate | middle layer much thicker than the thin layer C. FIG.
In the composition formula of the intermediate layer: (Al _1-a Ti _a ) (O _1-b N _b ), the technical reason for setting the value of a to 0.25 to 0.75, and the value of b to 0 The technical reason for setting .50 to 0.9 is the same as that described for the thin layer C.

Composition of the (Al, Cr) (ON) layer constituting the thin A layer of the upper layer:
The (Al _1-c Cr _c ) (O _1-d N _d ) layer of the thin layer A that constitutes an alternate laminated structure with the thin layer B described later has uniform wear resistance, heat resistance and toughness throughout the layer. However, the Cr component, which is a constituent component, provides excellent high-temperature strength and high-temperature lubricity, and the Al component supplements high-temperature hardness and heat resistance. For this reason, a low friction coefficient is maintained even under high temperature cutting conditions, and excellent heat resistance is exhibited. However, the c value (atomic ratio, the same applies hereinafter) indicating the content ratio of Cr in the total amount with Al is 0. If it is less than 20, the high temperature strength cannot be ensured, so abnormal damage is likely to occur at the boundary of the cutting edge and defects are likely to occur, so a long life cannot be expected. When the c value indicating the Cr content ratio exceeds 0.60, the Al content ratio is relatively decreased, and not only the high-temperature hardness required for high-speed cutting can be secured, but also wear resistance. The c value was determined to be 0.20 to 0.60 because the properties also deteriorated and it becomes difficult to prevent the occurrence of chipping.
D (atomic ratio) indicating the content ratio of N in the total amount of O and N is determined from the viewpoint of maintaining the high hardness and heat resistance of the (Al, Cr) (ON) layer. If the value exceeds 0.50, the heat resistance decreases due to a relative decrease in the O content, whereas if d decreases to 0.01 or less, the hardness decreases. Therefore, the value of d is determined to be more than 0.01 and 0.50 or less.

Composition of (Al, Mn) (ON) layer constituting upper thin B layer:
The (Al _1-e Mn _e ) (O _1-f N _f ) layer of the thin layer B that constitutes an alternate laminated structure with the thin layer A described above has uniform wear resistance, heat resistance and toughness throughout the layer. However, the Mn component, which is a constituent component, provides excellent high-temperature stability, and by using a composite oxynitride of Al and Mn, wear resistance is improved compared to each oxide. To do. As a result, high temperature hardness and heat resistance are complemented by cutting components. Therefore, a low friction coefficient is maintained even under high temperature cutting conditions, and excellent heat resistance is exhibited, but the e value (atomic ratio, the same applies hereinafter) indicating the content ratio of Mn in the total amount with Al is 0. If it is less than 10.10, high temperature strength cannot be ensured, so abnormal damage is caused at the boundary portion of the blade edge and defect is likely to occur, so a long life cannot be expected. When the e value indicating the Mn content ratio exceeds 0.50, the Al content ratio is relatively reduced, and not only the high-temperature hardness required for high-speed cutting cannot be secured, but also wear resistance. The e value was determined to be 0.10 to 0.50 because it was difficult to prevent the occurrence of chipping.
F (atomic ratio) indicating the content ratio of N in the total amount of O and N is determined from the viewpoint of maintaining high hardness and heat resistance of the (Al, Mn) (ON) layer,
When the value of f exceeds 0.50, the heat resistance is lowered due to the relative decrease in the O content, whereas when the value of f is 0.01 or less, the hardness is lowered. Therefore, the value of f is determined to be more than 0.01 and 0.50 or less.

Average layer thickness of the upper layer composed of the underlayer, the intermediate layer and the thin layers A and B and the total layer thickness of the hard coating layer:
If the average layer thickness of the base layer of the hard coating layer of the present invention is less than 0.5 μm, sufficient adhesion strength and wear resistance required for the base layer cannot be secured, while 5.0 μm If it exceeds 1, chipping and defects are likely to occur, so the total average layer thickness of the underlayer was determined to be 0.5 to 5.0 μm.
In addition, the base layer has an alternately laminated structure configured by alternately laminating thin layers C and thin layers D having different compositions, thereby improving the adhesion strength to the tool base and the adhesion strength to the intermediate layer. When the average layer thickness of each of the thin layers C and D is less than 1 nm, it is difficult to clearly form each thin layer having a predetermined composition, while each of the thin layers C and D is one layer. When the average layer thickness exceeds 50 nm, the chip strength and chipping resistance decrease due to the decrease in the film strength due to the coarsening of the particles. Therefore, the average layer thickness of each of the thin layer C and the thin layer D is 1 to 1. It was determined to be 50 nm.
Further, if the average layer thickness of the (Al, Ti) (ON) layer constituting the intermediate layer is less than 0.1 μm, the effect of increasing the adhesion strength between the underlayer and the upper layer is small, while the average When the layer thickness exceeds 1.0 μm, the chipping resistance and chipping resistance deteriorate, so the average layer thickness of the intermediate layer was determined to be 0.1 to 1.0 μm.
Further, the upper layer has an alternate laminated structure in which thin layers A and thin layers B having different compositions are alternately laminated, so that the growth of particles in each layer is prevented from being coarsened. In addition to improving the film strength and preventing the propagation and propagation of cracks by this laminated structure, the chipping resistance and chipping resistance are improved. If the average layer thickness is less than 1 nm, it is difficult to clearly form each thin layer as having a predetermined composition, and the above-described excellent characteristics of each thin layer cannot be exhibited. On the other hand, if the average layer thickness of each of the thin layer A and the thin layer B exceeds 50 nm, the chip strength and chipping resistance decrease due to the decrease in film strength due to the coarsening of the particles. The average layer thickness of each layer B was determined to be 1 to 50 nm.
Furthermore, when the total average layer thickness of the upper layer composed of the alternately laminated structure of the thin layer A and the thin layer B is less than 0.5 μm, excellent chipping resistance, chipping resistance, and wear resistance are exhibited over a long period of use. On the other hand, if the total average layer thickness of the upper layer exceeds 5.0 μm, defects and chipping are likely to occur. Therefore, the total average layer thickness of the upper layer is determined to be 0.5 to 5.0 μm. .
In addition, when the total average layer thickness of the whole hard coating layer including the underlayer, the intermediate layer, and the upper layer described above is less than 1.1 μm, excellent chipping resistance and chipping resistance can be sufficiently exhibited. On the other hand, if it exceeds 11.0 μm, on the contrary, chipping and defects are likely to occur. Therefore, the total average layer thickness of the entire hard coating layer was set to 1.1 to 11.0 μm.
Furthermore, when the total average layer thickness of the underlayer or the total average layer thickness of the upper layer is equal to or less than the average layer thickness of the intermediate layer, the ratio of the underlayer and the upper layer in the entire hard coating layer relatively decreases. Therefore, since sufficient wear resistance cannot be ensured, the total average layer thickness of the underlayer or the total average layer thickness of the upper layer is made larger than the average layer thickness of the intermediate layer.

As shown in FIG. 3, the hard coating layer of the present invention includes the (Al, Ti) (ON) layer constituting the thin layer C of the foundation layer and the (Al, Ti) N constituting the thin layer D of the foundation layer. (Al, Ti) (ON) layer constituting an intermediate layer, and (Al, Cr) (ON) layer constituting an upper layer thin layer A and thin layer B constituting an upper layer (Al, Mn) (ON) layer. Each of the above layers is, for example, a tool base is loaded into an arc ion plating apparatus which is one type of physical vapor deposition apparatus schematically shown in FIG. 1, and the inside of the apparatus is heated by a heater (not shown). In a state heated to a temperature of 500 ° C.,
(A) For example, arc discharge is generated between the anode electrode and the Al—Ti alloy as the cathode electrode (evaporation source) under the condition of current: 110 A, and simultaneously, nitrogen gas is introduced into the apparatus as a reaction gas. For example, the reaction atmosphere is 5.0 Pa, and the tool substrate is vapor-deposited for a predetermined time under the condition that a bias voltage of −100 V is applied, for example. The (Al, Ti) N layer which is the layer D is formed.
(B) Next, an arc discharge is generated between the anode electrode and the Al—Ti alloy as the cathode electrode (evaporation source), for example, under the condition of current: 110 A, and the atmosphere in the apparatus is simultaneously changed to 0.5 to 9. In a mixed atmosphere of oxygen and nitrogen of 0 Pa (for example, the ratio of the flow rate% of oxygen: nitrogen is 50:50), the tool base is deposited for a predetermined time under the condition that a bias voltage of, for example, −100 V is applied. An (Al, Ti) (ON) layer, which is a thin layer C of a base layer having a predetermined target layer thickness, is formed on the surface of the substrate.
The underlayer of the present invention can be formed by alternately repeating the steps (a) and (b) until a predetermined total layer thickness is reached.
(C) Next, an arc discharge is generated between the anode electrode and the Al—Ti alloy as the cathode electrode (evaporation source), for example, under the condition of current: 110 A, and the atmosphere in the apparatus is simultaneously changed to 0.5 to 9. A tool base is formed by vapor deposition for a predetermined time under a condition in which a bias voltage of −100 V is applied, for example, in an oxygen-nitrogen mixed atmosphere of 0 Pa (for example, a ratio of flow rate% of oxygen: nitrogen is 50:50). An (Al, Ti) (ON) layer, which is an intermediate layer having a predetermined target layer thickness, is formed on the surface.
(D) Next, arc discharge is generated between the anode electrode and the Al—Cr alloy as the cathode electrode (evaporation source), for example, under the condition of current: 110 A, and at the same time, the atmosphere in the apparatus is changed to 0.5 to 9. A tool base is formed by vapor deposition for a predetermined time under a condition in which a bias voltage of −100 V is applied, for example, in an oxygen-nitrogen mixed atmosphere of 0 Pa (for example, a ratio of flow rate% of oxygen: nitrogen is 50:50). The (Al, Cr) (ON) layer, which is a thin layer A having a predetermined target layer thickness, is formed on the surface.
(E) Next, a cathode electrode (evaporation source) made of an Al—Mn alloy having a predetermined composition is arranged in the apparatus, and, for example, an electric current is provided between the anode electrode and the Al—Mn alloy as the cathode electrode (evaporation source). : Arc discharge is generated under the condition of 110A, and the atmosphere in the apparatus is set to an oxygen-nitrogen mixed atmosphere of 0.5 to 9.0 Pa (for example, the ratio of oxygen: nitrogen flow% is 50:50). For example, an (Al, Mn) (ON) layer constituting a thin layer B having a predetermined target layer thickness is formed on the thin layer A by performing deposition for a predetermined time under the condition that a bias voltage of −100 V is applied. It is formed.
The upper layer of the present invention can be formed by alternately repeating the steps (d) and (e) until a predetermined total layer thickness is reached.
As a result, the hard coating layer of the present invention can be formed by vapor deposition by the steps (a) to (e).

  According to one aspect of the coated tool of the present invention, the hard coating layer has an alternately laminated structure of a thin layer C composed of an (Al, Ti) (ON) layer and a thin layer D composed of an (Al, Ti) N layer. A base layer, an intermediate layer made of (Al, Ti) (ON) layer, and a thin layer A made of (Al, Cr) (ON) layer and a thin layer made of (Al, Mn) (ON) layer By being composed of an upper layer having an alternating laminated structure with B, the underlayer increases the adhesion strength between the tool base and the intermediate layer, and the intermediate layer increases the adhesion strength between the underlayer and the upper layer, Due to the synergistic effect of the excellent wear resistance and heat resistance of the thin layer A of the upper layer and the excellent high temperature hardness and heat resistance and toughness of the thin layer B, the hard coating layer has excellent high temperature hardness, Heat resistance, high temperature strength, wear resistance, lubricity, impact resistance, chipping resistance, chip resistance As a result, it has excellent wear resistance over a long period of time even with high-speed cutting with high heat generation, especially with titanium alloys, heat-resistant alloys, stainless steel, etc. It exhibits heat resistance.

The arc ion plating apparatus used for forming the hard coating layer which comprises this invention coated tool and a comparative coated tool is shown, (a) is a schematic plan view, (b) is a schematic front view. It is a schematic explanatory drawing of the conventional arc ion plating apparatus explaining a prior art. It is a longitudinal cross-sectional block diagram of the hard coating layer which comprises this invention coated tool.

  Next, the coated tool of the present invention will be specifically described with reference to examples.

WC powder, TiC powder, ZrC powder, VC powder, TaC powder, NbC powder, Cr ₃ C ₂ powder, TiN powder, TaN powder, and Co powder all having an average particle diameter of 1 to 3 μm are prepared as raw material powders. These raw material powders are blended into the composition shown in Table 1, wet mixed by a ball mill for 72 hours, dried, and then pressed into a green compact at a pressure of 100 MPa. Medium, sintered at 1400 ° C. for 1 hour, and after sintering, tool bases A-1 to A-6 made of WC-base cemented carbide having an ISO standard / CNMG120408 insert shape were formed. .

In addition, as raw material powders, TiCN (mass ratio, TiC / TiN = 50/50) powder, Mo ₂ C powder, ZrC powder, NbC powder, TaC powder, WC, all having an average particle diameter of 0.5 to 2 μm. Prepare powder, Co powder, and Ni powder, mix these raw material powders into the composition shown in Table 2, wet mix for 24 hours with a ball mill, dry, and press-mold into green compact at 100 MPa pressure Then, this green compact was sintered in a nitrogen atmosphere of 2 kPa at a temperature of 1500 ° C. for 1 hour, and after sintering, a tool substrate B made of TiCN base cermet having an ISO standard / CNMG120408 insert shape was used. -1 to B-4 were formed.

(A) Next, each of the tool bases A-1 to A-6 and B-1 to B-4 is ultrasonically cleaned in acetone and dried, and then the arc ion plating apparatus shown in FIG. The first electrode is provided with three cathode electrodes (evaporation sources) that are mounted along the outer peripheral portion at a predetermined distance in the radial direction from the central axis on the inner rotary table, and that face each other across the rotary table. The Al—Ti alloy having a predetermined composition for forming the thin layer C, the thin layer D and the intermediate layer of the underlayer, the Al—Cr alloy having the predetermined composition for forming the thin layer A as the second electrode, As an electrode, an Al-Mn alloy having a predetermined composition for forming the thin layer B is disposed,
(B) First, the inside of the apparatus is evacuated and kept at a vacuum of 0.1 Pa or less, and the inside of the apparatus is heated to 500 ° C. with a heater, and then rotated to a tool base that rotates while rotating on a rotary table. A DC bias voltage is applied, and an arc discharge is generated by passing a current of 100 A between the Al—Ti alloy (cathode electrode) and the anode electrode, and the tool base surface is bombard washed.
(C) Next, the atmosphere in the apparatus is maintained in a nitrogen atmosphere of 0.5 to 9.0 Pa, and a DC bias voltage of -20 to -150 V is applied to the rotating tool base while rotating on the rotary table, and the cathode An arc discharge is generated by passing a current of 130 A between the Al—Ti alloy electrode, which is an electrode (evaporation source), and the anode electrode, and a thin layer D of an underlayer having a target composition and a target layer thickness shown in Table 3 The (Al, Ti) N layer is formed by vapor deposition.
(D) Next, for example, arc discharge is generated between the anode electrode and the Al—Ti alloy as the cathode electrode (evaporation source) under the condition of current: 130 A, and at the same time, the atmosphere in the apparatus is changed to 0.5-9. By depositing on the tool base for a predetermined time under a condition of applying a bias voltage of, for example, −100 V, in an oxygen / nitrogen mixed atmosphere of 0.0 Pa (for example, the ratio of flow rate% of oxygen: nitrogen is 50:50), The (Al, Ti) (ON) layer, which is a thin layer C of the base layer having the target composition and target layer thickness shown in Table 3, was formed by vapor deposition.
The above-mentioned (c) and (d) are alternately repeated to form an underlayer consisting of alternating layers of thin layers C and D having the target total average layer thickness shown in Table 3 on the surface of the tool base.
(E) Next, the atmosphere inside the apparatus is maintained in an oxygen-nitrogen mixed atmosphere of 0.5 to 9.0 Pa (for example, the ratio of the flow rate% of oxygen: nitrogen is 50:50), and rotates while rotating on the rotary table. A DC bias voltage of −20 to −150 V was applied to the tool base, and a current of 130 A was passed between the Al—Ti alloy electrode serving as the cathode electrode (evaporation source) and the anode electrode to generate arc discharge. The (Al, Ti) (ON) layer as an intermediate layer having the target composition and target layer thickness shown in FIG.
(F) Next, the atmosphere in the apparatus is maintained in an oxygen-nitrogen mixed atmosphere of 0.5 to 9.0 Pa (for example, the ratio of the flow rate% of oxygen: nitrogen is 50:50), and rotates while rotating on the rotary table. A DC bias voltage of −20 to −150 V was applied to the tool base, and a current of 130 A was passed between the Al—Cr alloy electrode as the cathode electrode (evaporation source) and the anode electrode to generate arc discharge. (Al, Cr) (ON) layer as the thin layer A having the target composition and target layer thickness shown in FIG.
(G) Next, the atmosphere in the apparatus is kept in an oxygen-nitrogen mixed atmosphere of 0.5 to 9.0 Pa (for example, the ratio of the flow rate% of oxygen: nitrogen is 50:50), and rotates while rotating on the rotary table. A direct current bias voltage of −50 to −150 V is applied to the tool base, and a current of 130 A is passed between the Al—Mn alloy of the cathode electrode and the anode electrode to generate an arc discharge. On top of this, an (Al, Mn) (ON) layer as a thin layer B having the target composition and target layer thickness shown in Table 4 is deposited and then arc discharge between the cathode electrode (evaporation source) and the anode electrode Stop
The above (f) and (g) were alternately repeated to form an alternate lamination having a target total average layer thickness shown in Table 4 on the intermediate layer.
Surface-coated inserts (hereinafter referred to as the present invention-coated inserts) 1 to 10 as the present invention-coated tools were produced by the above (a) to (g), respectively.

For comparison purposes,
(A) Each of the tool bases A-1 to A-6 and B-1 to B-4 is ultrasonically cleaned in acetone and dried, and then in the arc ion plating apparatus shown in FIG. Attached along the outer periphery at a predetermined distance in the radial direction from the central axis on the rotary table, and arranged with three cathode electrodes (evaporation sources) facing each other across the rotary table, as the first electrode, An Al—Ti alloy having a predetermined composition for forming the thin layer C, the thin layer D and the intermediate layer of the underlayer, and an Al—Cr alloy having a predetermined composition for forming the thin layer A as the second electrode, a third electrode As an Al-Mn alloy having a predetermined composition for forming the thin layer B,
(B) First, the inside of the apparatus is evacuated and kept at a vacuum of 0.1 Pa or less, and the inside of the apparatus is heated to 500 ° C. with a heater, and then rotated to a tool base that rotates while rotating on a rotary table. A DC bias voltage is applied, and an arc discharge is generated by passing a current of 100 A between the Al—Ti alloy (cathode electrode) and the anode electrode, and the tool base surface is bombard washed.
(C) Next, the atmosphere in the apparatus is maintained in a nitrogen atmosphere of 0.5 to 9.0 Pa, and a DC bias voltage of -20 to -150 V is applied to the rotating tool base while rotating on the rotary table, and the cathode An arc discharge is generated by flowing a current of 120 A between the Al—Ti alloy electrode, which is an electrode (evaporation source), and the anode electrode, and the underlayer D having the target composition and target layer thickness shown in Table 5 is generated. The (Al, Ti) N layer is formed by vapor deposition.
(D) Next, for example, an arc discharge is generated between the anode electrode and the Al—Ti alloy as the cathode electrode (evaporation source) under the condition of current: 120 A, and the atmosphere in the apparatus is changed to 0.5 to 9 at the same time. By depositing on the tool base for a predetermined time under a condition of applying a bias voltage of, for example, −100 V, in an oxygen / nitrogen mixed atmosphere of 0.0 Pa (for example, the ratio of flow rate% of oxygen: nitrogen is 50:50), The (Al, Ti) (ON) layer, which is a thin layer C of the base layer having the target composition and target layer thickness shown in Table 3, was formed by vapor deposition.
The above-mentioned (c) and (d) are alternately repeated to form an underlayer consisting of alternating layers of thin layers C and D having the target total average layer thickness shown in Table 3 on the surface of the tool base.
(E) Next, the atmosphere inside the apparatus is maintained in an oxygen-nitrogen mixed atmosphere of 0.5 to 9.0 Pa (for example, the ratio of the flow rate% of oxygen: nitrogen is 90:10), and rotates while rotating on the rotary table. A DC bias voltage of −20 to −150 V is applied to the tool base, and an arc discharge is generated by causing a current of 120 A to flow between the Al—Ti alloy electrode, which is the cathode electrode (evaporation source), and the anode electrode. (Al, Ti) (ON) layer as an intermediate layer having the target composition and target layer thickness shown in FIG. (F) Next, the atmosphere in the apparatus is maintained in an oxygen-nitrogen mixed atmosphere of 0.5 to 9.0 Pa (for example, the oxygen: nitrogen flow rate ratio is 90:10), and rotates while rotating on the rotary table. A DC bias voltage of −20 to −150 V is applied to the tool base, and a current of 120 A is passed between the Al—Cr alloy electrode, which is the cathode electrode (evaporation source), and the anode electrode to generate arc discharge. The (Al, Cr) (ON) layer as the thin layer A having the target composition and target layer thickness shown in Table 6 was formed by vapor deposition.
(G) Subsequently, the atmosphere inside the apparatus is maintained in an oxygen-nitrogen mixed atmosphere of 0.5 to 9.0 Pa (for example, the ratio of the flow rate% of oxygen: nitrogen is 5:95) and rotates while rotating on the rotary table. A DC bias voltage of −20 to −500 V is applied to the tool base to be used, and a current of 120 A is passed between the Al—Mn alloy of the cathode electrode and the anode electrode to generate an arc discharge. Further, after the (Al, Mn) (ON) layer as the thin layer B having the target composition and the target layer thickness shown in Table 6 is formed by vapor deposition, arc discharge between the cathode electrode (evaporation source) and the anode electrode is performed. Stop,
The above (f) and (g) were alternately repeated to form an alternate lamination having a target total average layer thickness shown in Table 6 on the intermediate layer.
Surface coated inserts (hereinafter referred to as comparative coated inserts) 1 to 6 as comparative coated tools were produced by the above (a) to (g), respectively.
The formation conditions (bias voltage, oxygen partial pressure, nitrogen partial pressure) of each layer are also shown in Tables 5 and 6.
In addition, about the comparison covering insert 1, it did not form alternate lamination | stacking, but was taken as the hard coating layer which consists only of (Al, Ti) N layer.

About this invention coated insert 1-10 and comparative coated insert 1-6, the cutting test was done on the following cutting conditions.
Work Material: Ni-19% Cr-18.5% Fe-5.2% Cd-5% Ta-3% Mo-0.9% Ti-0.5% Al-0.3% by mass% Ni-based alloy round bar having a composition of Si-0.2% Mn-0.05% Cu-0.04% C;
Cutting speed: 60 m / min. ,
Cutting depth: 1.8 mm,
Feed: 0.22 mm / rev. ,
Cutting time: 6 minutes,
Wet continuous high-speed high-feed cutting test of Ni-based alloy under the following conditions (cutting condition A) (normal cutting speed and feed are 35 m / min. And 0.15 mm / rev., Respectively),
Work material: JIS / SUS304 (HB180) round bar,
Cutting speed: 150 m / min. ,
Cutting depth: 2.0mm,
Feed: 0.32 mm / rev. ,
Cutting time: 9 minutes,
(Continuous cutting speed and feed rate are 120 m / min. And 0.3 mm / rev., Respectively)
Work material: Round bar of Ti base alloy having a composition of Ti-6% Al-4% V in mass%,
Cutting speed: 120 m / min. ,
Cutting depth: 2.2 mm,
Feed: 0.28 mm / rev. ,
Cutting time: 11 minutes,
Wet continuous high-speed high-cut cutting test of Ti-based alloy under the following conditions (cutting condition C) (normal cutting speed, cutting and feed are 100 m / min., 2.0 mm., 0.2 respectively. mm / rev.),
The flank wear width of the cutting edge was measured in any high-speed cutting test.
The measurement results are shown in Table 7.

As in Example 1, all of WC powder, TiC powder, ZrC powder, VC powder, TaC powder, NbC powder, Cr ₃ C ₂ powder, TiN powder, TaN powder, and Co powder having an average particle diameter of 1 to 3 μm. The raw material powder consisting of the above is blended in the composition shown in Table 1, wet mixed for 72 hours with a ball mill, dried, and then pressed into a green compact at a pressure of 100 MPa. , Temperature: Sintered at 1400 ° C. for 1 hour to form a round tool sintered body for forming a tool base having a diameter of 13 mm. WC-base cemented carbide tool bases (end mills) A-1 to A-6 having a four-blade square shape with a diameter x length of 10 mm x 22 mm and a twist angle of 30 degrees were manufactured. .

  Then, the surfaces of these tool bases (end mills) A-1 to A-6 were ultrasonically cleaned in acetone and dried, and then charged into the arc ion plating apparatus shown in FIG. 1 under the same conditions, the thin layer D composed of the (Al, Ti) N layer having the target composition and the target layer thickness shown in Table 8, and the target composition and the target layer thickness (Al, Ti) shown in Table 8. The thin layer C composed of the (ON) layer, the target composition shown in Table 8, and the intermediate layer composed of the (Al, Ti) (ON) layer having the target layer thickness, and the target composition and target layer shown in Table 9. Hardness with a target total average layer thickness shown in Table 9 consisting of an alternating layered structure of thin layers A composed of (Al, Cr) (ON) layers and thin layers B composed of (Al, Mn) (ON) layers By forming the coating layer by vapor deposition, the surface-coated cemented carbide engine of the present invention as the coated tool of the present invention is used. Mill (hereinafter, the present invention refers to the coating end mill) 10 was prepared, respectively.

For comparison purposes, the surfaces of the tool bases (end mills) A-1 to A-5 are ultrasonically cleaned in acetone and dried, and then loaded into the arc ion plating apparatus shown in FIG. Then, in the same process as in Example 1, using the formation conditions (bias voltage, nitrogen partial pressure) shown in Table 8, the target composition and the target layer thickness (Al, Ti) N layer shown in Table 10 are formed. The thin layer D and the thin layer C composed of the (Al, Ti) (ON) layer having the target composition and the target layer thickness shown in Table 10, and the target composition and the target layer thickness (Al, shown in Table 10). It consists of an intermediate layer composed of (Ti) (ON) layer, a thin layer A composed of (Al, Cr) (ON) layer and a (Al, Mn) (ON) layer of the target composition and target layer thickness shown in Table 11. Hard coating layer having a target total average layer thickness shown in Table 8 having an alternate laminated structure with thin layer B By vapor deposited surface coating cemented carbide end mills of the comparison coated tool (hereinafter, compared referred to as coated end mill) was produced, respectively 1-5.
In addition, about the comparison coating | coated end mill 1, the formation of an alternating lamination was not performed but it was set as the hard coating layer of only the (Al, Ti) N layer.

Next, for the present invention coated end mills 1-10 and comparative coated end mills 1-5,
Work Material-Plane Dimensions: 100mm x 250mm, Thickness: 50mm, Mass%, Ni-19% Cr-14% Co-4.5% Mo-2.5% Ti-2% Fe-1.2 Ni-base alloy plate material having a composition of% Al-0.7% Mn-0.4% Si,
Cutting speed: 65 m / min. ,
Groove depth (cut): 1.8 mm,
Table feed: 140mm / min,
Wet high-speed grooving test of Ni-based alloy under the following conditions (normal cutting speed and groove depth are 50 m / min. And 1.0 mm, respectively),
The cutting groove length was measured until the flank wear width of the outer peripheral edge of the cutting edge reached 0.1 mm, which is a guide for the service life.
The measurement results are shown in Tables 9 and 11, respectively.

  The round bar sintered body with a diameter of 13 mm manufactured in Example 2 was used, and from this round bar sintered body, the dimensions of the groove forming part diameter × length were 8 mm × 22 mm and the twist angle by grinding. WC base cemented carbide tool bases (drills) A-1 to A-6 each having a 30-degree two-blade shape were produced.

  Next, the cutting blades of these tool bases (drills) A-1 to A-6 are subjected to honing, ultrasonically cleaned in acetone, and dried in the arc ion plating apparatus shown in FIG. Under the same conditions as in Example 1, the target composition shown in Table 12 and the thin layer D composed of the (Al, Ti) N layer of the target layer thickness, and the target composition and target layer thickness shown in Table 12 The thin layer C composed of the (Al, Ti) (ON) layer, and the intermediate layer composed of the (Al, Ti) (ON) layer having the target composition and target layer thickness shown in Table 12, and A thin layer A composed of an (Al, Cr) (ON) layer having a target composition and a target layer thickness, and a thin layer consisting of an (Al, Mn) (ON) layer having a target composition and a target layer thickness also shown in Table 9. The hard cover having the target total layer thickness shown in Table 13 and having an alternate laminated structure with the layer B By depositing a layer, the present invention surface-coated cemented carbide drills of the present invention coated tool (hereinafter, the present invention refers to the coating drill) 1 to 10 were prepared, respectively.

  For the purpose of comparison, the surfaces of the tool bases (drills) A-1, 2, 4 to 6 are subjected to honing, ultrasonically cleaned in acetone and dried, and the arc shown in FIG. In the same process as in Example 1 using the ion plating apparatus, the formation conditions (bias voltage, nitrogen partial pressure) shown in Table 14 were used, and the target composition and target layer thickness (Al , Ti) a thin layer D composed of an N layer, a target composition shown in Table 14, a thin layer C composed of an (Al, Ti) (ON) layer having a target layer thickness, and a target composition shown in Table 14; An intermediate layer composed of an (Al, Ti) (ON) layer having a target layer thickness, a thin layer A composed of an (Al, Cr) (ON) layer having a target composition and a target layer thickness shown in Table 15, and Table 15 Intersection with thin layer B consisting of (Al, Mn) (ON) layers with the indicated target composition and target layer thickness Surface-coated carbide drills (hereinafter referred to as comparative coated drills) 1 to 5 as comparative coated tools are manufactured by vapor-depositing a hard coated layer having a target total layer thickness shown in Table 15 having a laminated structure. did. In addition, about the comparison covering drill 1, the formation of an alternating lamination was not performed but it was set as the hard coating layer only of the (Al, Ti) N layer.

Next, for the present invention coated drills 1-10 and comparative coated drills 1-5,
Work Material—Plane Size: 100 mm × 250 mm, Thickness: 50 mm, Mass%, Ni-19% Cr-18.5% Fe-5.2% Cd-5% Ta-3% Mo-0.9 Ni-based alloy plate having a composition of% Ti-0.5% Al-0.3% Si-0.2% Mn-0.05% Cu-0.04% C,
Cutting speed: 65 m / min. ,
Feed: 0.18 mm / rev,
Hole depth: 25 mm,
Wet high-speed drilling machining test of Ni-based alloy under the conditions (normal cutting speed and feed are 20 m / min. And 0.12 mm / rev, respectively),
(Using water-soluble cutting oil), and the number of drilling operations was measured until the flank wear width of the cutting edge surface reached 0.3 mm.
The measurement results are shown in Tables 13 and 15, respectively.

  It is a thin layer A constituting the hard coating layer of the present coated inserts 1 to 10, the present coated end mills 1 to 10, and the present coated drills 1 to 10 as the present coated tool obtained as a result (Al, Cr) (ON) layer and thin layer B (Al, Mn) (ON) layer composition, comparative coated inserts 1-6 as comparative coated tools, comparative coated end mills 1-5, and comparative coated drill 1 The composition of the (Al, Cr) (ON) layer which is the thin layer A and the (Al, Mn) (ON) layer which is the thin layer B constituting the hard coating layer 5 and the underlying layer (Al, Ti ) The composition of the thin layer D consisting of the N layer and the thin layer C consisting of the (Al, Ti) (ON) layer, and the composition of the (Al, Ti) (ON) layer as the intermediate layer were measured using a transmission electron microscope. Measured by the energy dispersive X-ray analysis method used. It showed target composition substantially the same composition.

  Moreover, when the average layer thickness of each layer which comprises the said hard coating layer was cross-sectional measured using the scanning electron microscope, all showed the average layer thickness (average value of five places) substantially equal to target layer thickness. .

From the results shown in Tables 7, 9, 11, 13, and 15, the coated tool of the present invention has a predetermined composition on the tool substrate, an underlayer comprising alternating layers of thin layers C and D having a target layer thickness, Further, after forming an intermediate layer having a predetermined composition and a target layer thickness, a result of forming an alternate stack composed of a thin layer A having a predetermined composition and a target layer thickness and a thin layer B having a predetermined composition and a target layer thickness In the state in which the (Al, Cr) (ON) layer, which is the thin layer A, is firmly bonded to the surface of the tool substrate, the chipping resistance, high temperature hardness, and high temperature strength are improved, and the thin layer B (Al , Mn) (ON) layer has excellent heat resistance and wear resistance, and due to the synergistic effect of alternating lamination of thin layer A and thin layer B with different compositions, impact resistance, chipping resistance, crack resistance progress As a result, the high-speed cutting of titanium alloy, heat-resistant alloy, stainless steel, etc. , Excellent chipping resistance can be secured, without chipping, exhibit excellent wear resistance for a long time.
On the other hand, in the comparative coated tool in which any one of the layers constituting the hard coating layer deviates from the composition and average layer thickness specified in the present invention, all are high-speed cutting of titanium alloy, heat-resistant alloy, and stainless steel. It is apparent that the wear resistance is not sufficient and the toughness of the film is reduced, so that chipping occurs at the cutting edge and the service life is reached in a relatively short time.

  As described above, the coated tool of the present invention is excellent in wear resistance and fracture resistance in high-speed cutting such as titanium alloy, heat-resistant alloy, stainless steel as well as cutting of general work materials. Since it exhibits excellent cutting performance and exhibits excellent cutting performance over a long period of time, it can satisfactorily respond to automation of the cutting apparatus, labor saving and energy saving of cutting, and cost reduction.

Claims (1)

In a surface-coated cutting tool formed by forming a hard coating layer on the surface of a tool base composed of tungsten carbide-based cemented carbide or titanium carbonitride-based cermet,
The hard coating layer is
(A) an underlayer having an alternating layered structure of thin layers C and D formed on the surface of the tool base, wherein the total average layer thickness of the alternating layers is 0.5 to 5.0 μm;
(B) having an average layer thickness of 0.1 to 1.0 μm formed on the surface of the underlayer, and
Composition formula: (Al _1-a Ti _a ) (O _1-b N _b ) (where a represents the content ratio of Ti in the total amount of Al and Ti, and the atomic ratio is 0.25 ≦ a ≦ B represents the content ratio of N in the total amount of O and N, and an intermediate layer satisfying an atomic ratio of 0.50 ≦ b ≦ 0.9);
(C) It consists of an alternating layered structure of thin layers A and thin layers B formed on the surface of the intermediate layer, consisting of an upper layer having a total average layer thickness of 0.5 to 5.0 μm.
(D) The thin layer C has an average layer thickness of 1 to 50 nm, and
Composition formula: (Al _1-a Ti _a ) (O _1-b N _b ) (where a represents the content ratio of Ti in the total amount of Al and Ti, and the atomic ratio is 0.25 ≦ a ≦ Further, b represents the content ratio of N in the total amount of O and N, and the composite nitridation of Al and Ti satisfying the atomic ratio of 0.50 ≦ b ≦ 0.9) Consists of layers
(E) the thin layer D has an average layer thickness of 1 to 50 nm, and
Composition formula: (Al _1-g Ti _g ) N (where g represents the content ratio of Ti in the total amount of Al and Ti, and the atomic ratio is 0.25 ≦ g ≦ 0.75) It consists of a composite nitride layer of Al and Ti that is satisfactory,
(F) The thin layer A has an average layer thickness of 1 to 50 nm, and
Composition formula: (Al _1-c Cr _c ) (O _1-d N _d ) (where c represents the content ratio of Cr in the total amount of Al and Cr, and the atomic ratio is 0.20 ≦ c ≦ In addition, d represents the content ratio of N in the total amount of O and N, and the composite nitridation of Al and Cr satisfying the atomic ratio of 0.01 ≦ d ≦ 0.50) Consists of layers
(G) The thin layer B has an average layer thickness of 1 to 50 nm, and
Composition formula: (Al _1-e Mn _e ) (O _1-f N _f ) (where e represents the content ratio of Mn in the total amount of Al and Mn, and the atomic ratio is 0.10 ≦ e ≦ In addition, f indicates the content ratio of N in the total amount of O and N, and the composite nitridation of Al and Mn satisfying the atomic ratio of 0.01 ≦ f ≦ 0.50) Consists of layers
(H) The base layer and the upper layer are thicker than the intermediate layer, and the total average thickness of the hard coating layer is 1.1 to 11.0 μm. Surface coated cutting tool.