JP2012192517A - Surface-coated cutting tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a surface-coated cutting tool that exhibits excellent chipping resistance and wear resistance in high-speed cutting such as high-speed gear cutting, high-speed milling, and high-speed drilling.
SOLUTION: The composition formula: [Al _X Cr _Y Si _Z ] N (atomic ratio, 0.2 ≦ X ≦ 0.45, on the surface of a tool substrate such as a carbide substrate, a cermet substrate, or a high-speed tool steel substrate. 0.4 ≦ Y ≦ 0.75, 0.01 ≦ Z ≦ 0.2, X + Y + Z = 1), and a thin layer A composed of an (Al, Cr, Si) N layer, and [Al _U Ti _V Si _W N (atomic ratio, 0.05 ≦ U ≦ 0.75, 0.15 ≦ V ≦ 0.94, 0.01 ≦ W ≦ 0.1, U + V + W = 1) is satisfied (Al, Ti, Si) ) An upper layer having an alternately laminated structure with a thin layer B made of an N layer, and an underlayer of the (Al, Ti, Si) N layer formed between the upper layer and the tool base surface. A hard coating layer is formed.
[Selection figure] None

Description

  The present invention has excellent high-temperature hardness, high-temperature toughness, high-temperature strength, and heat-resistant plastic deformability with a hard coating layer, and is accompanied by high heat generation such as high-speed gear cutting, high-speed milling, and high-speed drilling. At the same time, the hard coating layer has excellent chipping resistance and wear resistance even when it is used for cutting that requires a large impact and mechanical load on the cutting edge, and has excellent tool characteristics. The present invention relates to a surface-coated cutting tool (hereinafter referred to as a coated tool) that can be demonstrated over a long period of time.

  In general, as a coated tool, for throwing inserts that can be used detachably attached to the tip of a cutting tool for turning and planing of various materials such as steel and cast iron, and for drilling and cutting the work material Known drills and miniature drills, end mills used for chamfering and grooving, shoulder processing, etc. of the work material, solid hob, pinion cutter used for gear cutting of the tooth profile of the work material, etc. Yes.

Specific examples of the coated tool include tungsten carbide (hereinafter referred to as WC) based cemented carbide, titanium carbonitride (hereinafter referred to as TiCN) based cermet, and high-speed tool steel (hereinafter referred to as high speed steel). On the surface of the configured tool base,
Composition formula: When expressed by [Al _X Cr _Y Si _Z ] N,
Al / Cr / Si composite nitride layer satisfying 0.75 ≦ X ≦ 0.95, 0.05 ≦ Y ≦ 0.25, and X + Y + Z = 1 (where X, Y, and Z are atomic ratios) It is known to improve the heat resistance and wear resistance of the coated tool by providing at least one hard coating layer (hereinafter referred to as (Al, Cr, Si) N layer).
Also, on the surface of the tool base,
Composition formula: [Al _U Ti _V Si _W ] N
Composite nitride layer of Al, Ti, and Si satisfying 0.05 ≦ U ≦ 0.75, 0.01 ≦ W ≦ 0.10, U + V + W = 1 (where U, V, and W are atomic ratios) It is also known to improve the oxidation resistance and wear resistance of the coated tool by providing a hard coating layer (hereinafter referred to as (Al, Ti, Si) N layer).

  The above-mentioned conventional coated tool is, for example, loaded with the tool base into an arc ion plating apparatus which is a kind of physical vapor deposition apparatus shown in a schematic explanatory view in FIG. While being heated to a temperature, an arc discharge is generated between the cathode electrode (evaporation source) having a component composition corresponding to the type of hard coating layer to be vapor deposited and the anode electrode, for example, under a current of 90 A, and at the same time Nitrogen gas is introduced into the apparatus as a reaction gas to form a reaction atmosphere of 2 Pa. On the other hand, the hard coating layer is formed on the surface of the tool base under the condition that a bias voltage of, for example, −100 V is applied to the tool base. It is also known that it is manufactured by vapor deposition.

Japanese Patent Laid-Open No. 2006-175569 Japanese Patent No. 2793773

  In recent years, the performance of cutting machines has been remarkable. On the other hand, there are strong demands for labor saving and energy saving and further cost reduction for cutting. With this, cutting tends to be faster. In conventional coated tools, when this is used for cutting under normal cutting conditions such as steel and cast iron, no particular problem arises, but this can be achieved, for example, by high-speed gear cutting or high-speed milling. When used for cutting that involves high heat generation, such as high-speed drilling, and that imposes a large impact or mechanical load on the cutting edge, the toughness of the hard coating layer is insufficient, or the thermoplastic deformation Due to the occurrence of uneven wear due to, the occurrence of chipping and chipping cannot be suppressed, and the progress of wear is promoted, so the service life is reached in a relatively short time.

  In view of the above, the inventors of the present invention are accompanied by high heat generation such as high-speed gear cutting, high-speed milling, high-speed drilling, etc. In order to develop a coated tool that exhibits excellent chipping resistance and wear resistance under hard cutting conditions, a layer forming material constituting the hard coating layer of the conventional coated tool and its structure As a result of conducting research focusing on the following, the following findings were obtained.

(A) The Al component in the (Al, Cr, Si) N layer constituting the hard coating layer of the conventional coated tool (see Patent Document 1) has high temperature hardness, the Cr component has high temperature toughness and high temperature strength. In addition to improving the high-temperature oxidation resistance in the state of coexistence of Al and Cr, the Si component also has the effect of improving the heat-resistant plastic deformation, but accompanied by the generation of high heat, and against the cutting edge However, under severe cutting conditions such as high-speed gear cutting, high-speed milling, and high-speed drilling that require a large impact and mechanical load, it cannot be said that high-temperature toughness and high-temperature strength are sufficient. In contrast, increasing the Cr content ratio to improve high-temperature toughness and high-temperature strength results in deterioration of wear resistance due to a relative decrease in Al content ratio. (Al, Cr, Si) chipping resistance in the hard coating layer consisting of N layers, that there is a limit to suppression and improvement of fracture resistance.

(B) On the other hand, the Al component and Si component in the (Al, Ti, Si) N layer constituting the hard coating layer of the conventional coated tool (see Patent Document 2) have the same action as described above, and Since the Ti component has the effect of further improving high temperature toughness and high temperature strength, the (Al, Ti, Si) N layer is used even under severe cutting conditions such as high speed gear cutting, high speed milling, and high speed drilling. The hard coating layer made of is excellent in chipping resistance and chipping resistance, but on the other hand, it is inferior in wear resistance due to lack of high temperature hardness and heat plastic deformation.

(C) Therefore, the thin layer A composed of the (Al, Cr, Si) N layer of the above (a) having a predetermined composition and a predetermined layer thickness, and (Al, When the hard coating layer is formed by alternately laminating the thin layers B composed of (Ti, Si) N layers, the hard coating layer composed of the alternately laminated structure of the thin layers A and B has a predetermined thickness. Excellent high temperature toughness possessed by the thin layer B without impairing the superior wear resistance possessed by the thin layer A as a whole hard coating layer by setting the layer thickness within a predetermined range.・ Because it has high strength at the same time, the coated tool with the hard coating layer consisting of the alternating layered structure of thin layer A and thin layer B is accompanied by high heat generation and has a great impact on the cutting edge. High speed gear cutting, high speed milling and high speed drill Even in the case of using the cutting severe cutting conditions etc., to exhibit excellent chipping resistance, fracture resistance and wear resistance.

This invention has been made based on the above findings,
“(1) In a surface-coated cutting tool in which a hard coating layer is formed on the surface of a tool base,
The hard coating layer is composed of an upper layer having an alternately laminated structure of thin layers A and B, and an underlayer formed between the upper layer and the tool base surface,
The upper layer thin layer A and thin layer B each have a layer thickness of 0.01 to 0.1 μm, and thin layer A and thin layer B have a total layer thickness of 1 to 10 μm, ,
(A) The thin layer A is
Composition formula: When expressed by [Al _X Cr _Y Si _Z ] N,
0.2 ≦ X ≦ 0.45, 0.4 ≦ Y ≦ 0.75, 0.01 ≦ Z ≦ 0.2, and X + Y + Z = 1 (where X, Y, and Z are atomic ratios) are satisfied. A composite nitride layer of Al, Cr and Si;
(B) The thin layer B is
Composition formula: [Al _U Ti _V Si _W ] N
0.05 ≦ U ≦ 0.75, 0.15 ≦ V ≦ 0.94, 0.01 ≦ W ≦ 0.1, U + V + W = 1 (where U, V, and W are atomic ratios) A composite nitride layer of Al, Ti and Si,
The surface-coated cutting tool (coated tool), wherein the underlayer has a layer thickness of 0.5 to 10 μm and has a composition satisfying the composition formula of the thin layer B.
(2) The surface-coated cutting tool (coated tool) according to (1), wherein the surface-coated cutting tool (coated tool) is a gear cutting tool using high-speed tool steel as a tool base.
(3) The surface-coated cutting tool (coated tool) according to (1), wherein the surface-coated cutting tool (coated tool) is an end mill having a high-speed tool steel as a tool base.
(4) The surface-coated cutting tool (coated tool) according to (1), wherein the surface-coated cutting tool (coated tool) is an end mill or a drill having a tungsten carbide base cemented carbide as a tool base. "

  Next, the reason why the numerical values of the hard coating layer of the coated tool of the present invention are limited as described above will be described.

(A) Thin layer A
The Al component in the thin layer A composed of the (Al, Cr, Si) N layer is improved in high-temperature hardness, and the Cr component is improved in high-temperature toughness and high-temperature strength. The Si component has the effect of improving the heat-resistant plastic deformation. And if X value (atomic ratio) which shows the content rate of Al is less than 0.2 in the ratio which occupies for the total amount of Cr and Si, the minimum high temperature hardness and high temperature oxidation resistance cannot be secured, If this X value exceeds 0.45, high temperature toughness and high temperature strength will decrease, causing chipping and chipping. Therefore, the X value should be 0.2-0. 45. Further, if the Y value (atomic ratio) indicating the Cr content ratio is less than 0.4 in the ratio of the total amount of Al and Si, the minimum required high temperature toughness and high temperature strength cannot be ensured. The occurrence of chipping / defects cannot be suppressed. On the other hand, if the Y value exceeds 0.75, the wear progress is promoted due to a decrease in the relative Al content. It was set to 0.75. Furthermore, if the Z value (atomic ratio) indicating the content ratio of Si is less than 0.01 in the ratio of the total amount of Al and Cr, it is not possible to expect an improvement in wear resistance due to an improvement in heat plastic deformation, On the other hand, if the Z value exceeds 0.2, the tendency to decrease the wear resistance improving effect is observed, so the Z value was determined to be 0.01 to 0.2.
For X, Y, and Z, particularly desirable ranges are 0.35 ≦ X ≦ 0.45, 0.4 ≦ Y ≦ 0.55, and 0.03 ≦ Z ≦ 0.10.

(B) Thin layer B
The thin layer B composed of the (Al, Ti, Si) N layers constituting the alternately laminated structure with the thin layer A is provided to supplement the characteristics (high temperature toughness and high temperature strength) that are lacking in the thin layer A. Layer.
As already described, the thin layer A has excellent wear resistance especially by containing the Al component and Si component, and further has a predetermined chipping resistance and fracture resistance by containing the Cr component. Although it is held, it generates heat and withstands use under severe cutting conditions that impose a large impact and mechanical load on the cutting edge, such as high-speed gear cutting, high-speed milling, and high-speed drilling. For this purpose, the thin layer A is required to have further high-temperature toughness and high-temperature strength, and in order to ensure this, it is necessary to contain more Cr in the thin layer A. The content ratios of Al and Si must be reduced. In that case, the thin layer A has insufficient high-temperature hardness and high-temperature oxidation resistance, which leads to a decrease in wear resistance. C in layer A It is not possible to achieve a further increase of the content.
Therefore, in the present invention, the thin layer B composed of the (Al, Ti, Si) N layer is alternately laminated with the thin layer A to form a hard coating layer composed of the alternately laminated structure of the thin layer A and the thin layer B. The high-temperature toughness that the thin layer A has, the high-temperature toughness that the thin layer A lacks, the high-temperature toughness that the adjacent thin layer B has, The high-temperature strength makes up for it, so that the entire hard coating layer exhibits excellent chipping resistance, chipping resistance, and wear resistance.
The effects of the Al component and Si component in the composition formula of the thin layer B are the same as in the case of the thin layer A, but the U value (atomic ratio) indicating the Al content is less than 0.05, or If the W value (atomic ratio) indicating the ratio is less than 0.01, it is impossible to ensure the minimum required high-temperature hardness, high-temperature oxidation resistance, and heat-resistant plastic deformability, resulting in reduced wear resistance. When the U value exceeds 0.75, the effect of improving the high temperature toughness and high temperature strength due to the addition of the Ti component cannot be expected due to the relative decrease in the Ti component content, and the W value is 0. If it exceeds .1, a tendency to lower the wear resistance improving effect is observed. Therefore, the U value indicating the Al content ratio was determined to be 0.05 to 0.75, and the W value indicating the Si content ratio was determined to be 0.01 to 0.1. Further, when the V value (atomic ratio) indicating the Ti content is less than 0.15, it is not possible to expect a further excellent effect of improving high temperature toughness and high temperature strength, while the V value is 0.94. In such a case, it is impossible to ensure the minimum required high-temperature hardness and high-temperature oxidation resistance due to a decrease in the content ratio of the relative Al component and Si component. V value which shows a ratio was defined as 0.15-0.94.
Regarding U, V, and W, particularly desirable ranges are 0.45 ≦ U ≦ 0.55, 0.4 ≦ V ≦ 0.5, and 0.03 ≦ W ≦ 0.07.

(C) Layer thickness If the thickness of each of the thin layer A and the thin layer B is less than 0.01 μm, it is difficult to clearly form each thin layer as having a predetermined composition. The effect of improving wear resistance and the effect of improving the high temperature toughness by the thin layer B are not sufficiently exhibited. On the other hand, if the thickness of each of the thin layer A and the thin layer B exceeds 0.1 μm, the disadvantages of each thin layer That is, if it is a thin layer A, insufficient toughness and insufficient strength, and if it is a thin layer B, insufficient wear resistance may appear locally in the layer, which may lead to deterioration of the properties of the entire hard coating layer. The thickness of each of the thin layer A and the thin layer B was determined to be 0.01 to 0.1 μm.
That is, the thin layer B is provided in order to compensate for insufficient characteristics among the characteristics of the thin layer A, but each of the thin layers A and B has a thickness of 0.01 to 0.1 μm. Within the range, the hard coating layer composed of the alternately laminated structure of the thin layer A and the thin layer B has excellent high temperature toughness without impairing high temperature hardness, high temperature oxidation resistance, and heat plastic deformation, It acts as if it had one layer with high temperature strength, but if the thickness of the thin layer A and thin layer B exceeds 0.1 μm, the toughness of the thin layer A, the strength is insufficient, The lack of wear resistance of the thin layer B becomes apparent.
In addition, the layer (upper layer) having an alternately laminated structure of the thin layer A and the thin layer B cannot exhibit excellent characteristics when the total layer thickness is less than 1 μm, and the total layer thickness exceeds 10 μm. Then, since chipping and defects are likely to occur, the total layer thickness of the layer (upper layer) composed of the alternately laminated structure of the thin layer A and the thin layer B is set to 1 to 10 μm, preferably 1 to 5 μm.

(D) Underlayer When the thin layer A and the thin layer B are alternately laminated on the surface of the tool base, for example, by physical vapor deposition, residual compressive stress is generated in the layer, and such a hard coating layer is formed. When the provided coated tool is used under severer cutting conditions, the compression residual stress makes the adhesion between the tool base and the hard coating layer unstable. Therefore, in such a case, it is necessary to further increase the adhesion strength between the surface of the tool base and the hard coating layer having an alternately laminated structure. As a means for that purpose, an underlayer is provided on the surface of the tool base. It is effective to form and increase the adhesion strength. In particular, in the present invention, the hard coating layer is formed from an upper layer having an alternately laminated structure of thin layers A and B, and an underlayer interposed between the upper layer and the tool base surface, And by forming the underlayer with a layer thickness of 0.5 to 10 μm and having the same composition as the thin layer A or the thin layer B, the adhesion between the tool substrate and the hard coating layer is improved, Even when used under severer cutting conditions, it has been confirmed that stable cutting can be performed without causing peeling or missing of the hard coating layer.
In addition, if the layer thickness of the underlayer is less than 0.5 μm, the effect of improving the adhesion cannot be obtained. On the other hand, if the layer thickness exceeds 10 μm, the residual compressive stress accumulates and cracks are likely to occur, resulting in stable adhesion. Therefore, the thickness of the underlayer is set to 0.5 to 10 μm, preferably 2 to 6 μm.

(E) Tool substrate As the tool substrate of the coated tool, various conventionally known substrates such as WC-based cemented carbide, TiCN-based cermet, and high-speed tool steel (high speed) can be used.
For example, a hard coating layer is formed on such various tool substrates by physical vapor deposition. In order to further increase the adhesion strength between the substrate and the hard coating layer, the surface roughness of the tool substrate is set to JIS Rz 1.6 μm or less. It is desirable to keep it.
In this invention, for the purpose of identifying use, unused, etc. on the outermost surface of the coated tool, for example, a coloring layer such as a TiN layer (gold color) can be provided, but the thickness is 0.5 μm or less. Is enough.

  In the surface-coated cutting tool according to the present invention, the hard coating layer includes at least a thin layer A composed of (Al, Cr, Si) N layers and a thin layer B composed of (Al, Ti, Si) N layers. It has excellent high-temperature hardness, high-temperature toughness, high-temperature strength, and heat-resistant plastic deformation, and the adhesion strength is improved by providing an underlayer with the same composition as the thin layer B as the lower layer. Therefore, high-temperature hardness with excellent hard coating layer even in high-speed gear cutting, high-speed milling, and high-speed drilling, which are accompanied by high heat generation and a large impact / mechanical load on the cutting edge. Exhibits high temperature toughness, high temperature strength, and heat-resistant plastic deformation. As a result, there is no occurrence of chipping, chipping, uneven wear, and peeling, and it exhibits excellent chipping resistance and excellent wear resistance over a long period of time. is there.

The arc ion plating apparatus used for forming the hard coating layer of the coating tool of this invention is shown, (a) is a schematic plan view, (b) is a schematic front view. It is a schematic explanatory drawing of a normal arc ion plating apparatus. It is a schematic perspective view of a solid hob. It is a schematic perspective view of a disk-type pinion cutter.

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

  The material is made of a high-speed tool steel of JIS / SKH51 and SKH55, and has a diameter of 90 mm x length: 130 mm, and has an overall diameter of 85 mm x length: 100 mm by machining. And the high-speed gear cutting tool main body (solid hob) shown by the schematic perspective view in FIG. 3 having the shape of 4 threads left twist × 16 grooves was manufactured.

(A) Next, each of the above-mentioned two types of high-speed gear cutting tool main body (solid hob) 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, each of the cathode electrodes (evaporation source) has a component composition corresponding to the target composition shown in Table 1. The thin layer A forming Al—Cr—Si alloy and the other side cathode electrode (evaporation source) having the same component composition corresponding to the target composition shown in Table 1, Al—Ti— Si alloys are arranged opposite to each other with the rotary table in between (in the case of two types of cathode electrodes, one of the cathode electrodes for forming the thin layer A or the thin layer B is also used as the cathode electrode for forming the underlying layer. Doo is possible. In addition, as a dedicated cathode for undercoat layer formation, it is of course possible to also separately receive a third electrode).
(B) First, after the inside of the apparatus is evacuated and kept at a vacuum of 0.1 Pa or less, the inside of the apparatus is heated to 400 ° C. with a heater, and then rotates on the rotary table while rotating on the rotary tool main body base. A DC bias voltage of −800 V is applied, and an arc discharge is generated by passing a current of 100 A between the bombard cleaning electrode (for example, Al—Cr—Si alloy for forming the thin layer A) and the anode electrode, and The surface of the main body of the gear cutting tool body is bombarded.
(C) Nitrogen gas is introduced into the apparatus as a reaction gas to make a reaction atmosphere of 3 Pa, and a DC bias voltage of −35 to −45 V is applied to the gear cutting tool main body rotating while rotating on the rotary table. In addition, an arc discharge is generated by passing a current of 100 A between the Al-Ti-Si alloy for forming the thin layer B and the anode electrode, and the surface of the high-speed gear cutting tool main body is shown in Table 1. A base layer (a composition similar to that of the thin layer B) having a target composition and a target layer thickness is formed by vapor deposition.
(D) Next, nitrogen gas is introduced as a reaction gas into the apparatus to make a reaction atmosphere of 2 Pa, and a DC bias voltage of −25 to −35 V is applied to the gear cutting tool main body rotating while rotating on the rotary table. Is applied, a predetermined current in the range of 50 to 200 A is passed between the cathode electrode and the anode electrode of the Al-Ti-Si alloy for forming the thin layer B to generate arc discharge, and the above-mentioned gear cutting A thin layer B having a predetermined layer thickness is formed on the base layer on the tool body base, and after the thin layer B is formed, the arc discharge is stopped, and the Al-Cr-Si alloy cathode for forming the thin layer A is used instead. Similarly, a predetermined current in the range of 50 to 200 A is passed between the electrode and the anode electrode to generate arc discharge to form a thin layer A having a predetermined layer thickness, and then the arc discharge is stopped (the underlying layer is a thin layer). If the layer has the same composition as B, A may be started), the formation of the thin layer B by arc discharge between the cathode electrode and the anode electrode of the Al-Ti-Si alloy for forming the thin layer B, and the Al- The thin layer A is alternately and repeatedly formed by arc discharge between the cathode electrode and the anode electrode of the Cr—Si alloy.
According to the above procedures (a) to (d), on the surface of the high-speed gear cutting tool main body substrate, the base composition of the target composition and target layer thickness shown in Table 1 along the layer thickness direction is also shown in Table 1. The coated high-speed gear cutting tools 1 to 3 of the present invention were manufactured by vapor-depositing an upper layer composed of alternately laminated thin layers A and B having a target composition and a target layer thickness.

  For comparison purposes, the high-speed gear cutting tool main body made of the above two types of materials is ultrasonically cleaned in acetone and dried, and then loaded into the arc ion plating apparatus shown in FIG. As the cathode electrode (evaporation source), an Al—Cr—Si alloy (Al—Ti—Si alloy) having a component composition corresponding to the target composition shown in Table 2 was mounted, and the apparatus was first evacuated. The inside of the apparatus is heated to 400 ° C. with a heater while maintaining a vacuum of 0.1 Pa or less, and a −800 V DC bias voltage is applied to the gear cutting tool main body, and the Al—Cr— of the cathode electrode is applied. An arc discharge is generated by passing a current of 100 A between the Si alloy (or Al—Ti—Si alloy) and the anode electrode, so that the surface of the main body of the cutting tool main body is the Al—Cr—Si alloy (there is Is bombarded with Al—Ti—Si alloy), and then nitrogen gas is introduced into the apparatus as a reaction gas to make a reaction atmosphere of 3 Pa, and a bias voltage applied to the gear cutting tool main body is −35 to − The voltage is lowered to 45 V, and an arc discharge is generated between the cathode electrode and the anode electrode of the Al-Cr-Si alloy (or Al-Ti-Si alloy). Hard coating layer composed of an (Al, Cr, Si) N layer having a single phase structure with a target composition and target layer thickness shown in FIG. 2 (or a single phase structure with a target composition and target layer thickness shown in Table 2 (Al, Ti, Si) N layer) is formed by vapor deposition to form coated high-speed gear cutting tools 1-16 (hereinafter referred to as comparative coated high-speed gear cutting tools 1-16). And elephants.

Next, using the above-described coated high-speed gear cutting tools 1 to 3 and comparative coated high-speed gear cutting tools 1 to 8, the material is JIS · SCr420H for the work material.
Module: 1.75, pressure angle: 17.5 degrees, number of teeth: 48, twist angle: 25 degrees left-handed, tooth width: processing of gears with dimensions and shapes of 50 mm,
Cutting speed (rotational speed): 250 m / min,
Feed: 2.5 mm / rev,
Processing form: climb, no shift, dry (air blow),
Under the conditions of high speed gear cutting (note that the cutting speed in the case of processing the gear made of the work material is usually 200 m / min),
The number of gears processed until the flank wear width reached 0.2 mm was measured.
The measurement results are shown in Tables 1 and 2, respectively.

  Further, as a high-speed gear cutting tool body, from a material having the same outer diameter: 105 mm × thickness: 22 mm made of high-speed tool steel of the same material as JIS / SKH51 and SKH55, the pitch circle diameter by machining: A disk-type pinion cutter body base body (100 type described in JIS B 4356) shown in a schematic perspective view in FIG. 4 having an overall size of 100 mm × thickness: 18 mm and a shape of the number of cutter teeth: 50. Manufactured.

  Next, the surface of the high-speed gear cutting tool body (pinion cutter) base body was ultrasonically cleaned in acetone and dried, and then charged into the arc ion plating apparatus shown in FIG. Under the same conditions as above, the underlayer of the target composition and target layer thickness shown in Table 1 along the layer thickness direction, and the alternate lamination of thin layer A and thin layer B of the target composition and target layer thickness also shown in Table 1 The present invention coated high-speed gear cutting tools 4 to 6 were produced by vapor-depositing an upper layer made of

  For comparison purposes, the surface of the high-speed gear cutting tool body (pinion cutter) substrate is ultrasonically cleaned in acetone and dried, and then loaded into the arc ion plating apparatus shown in FIG. Under the same conditions as in Example 1 above, a hard coating layer composed of an (Al, Cr, Si) N layer having a single-phase structure with the target composition and target layer thickness shown in Table 2 along the layer thickness direction ( Alternatively, by coating (Al, Ti, Si) N layer) having a single phase structure with the target composition and target layer thickness shown in Table 2, the coated gear cutting tools 9 to 16 (hereinafter referred to as comparative coated high-speed teeth) Cutting tools 9 to 16) were produced.

Next, using the above-described coated high-speed gear cutting tools 4 to 6 and comparative coated high-speed gear cutting tools 9 to 16, the work material is JIS / SCr420H,
Module: 2, Pressure angle: 20 degrees, Number of teeth: 15, Teeth width: Processing of gears with dimensions and shapes of 22.5 mm,
Number of strokes: 1200 stroke / min,
Circumferential feed: 0.3 mm / stroke,
Radial feed: 0.03 mm / stroke,
The high speed gear cutting is performed under the conditions (note that the number of strokes in the case of processing the gear made of the work material is usually 800 strokes / min),
The number of gears processed until the flank wear width reached 0.2 mm was measured.
The measurement results are shown in Tables 1 and 2, respectively.
In Tables 1, 2, 4 to 9, the content ratios of the Al component, the Cr component, the Ti component, and the Si component are shown as an atomic ratio as the target composition.

The composition of the base layer, the thin layer A and the thin layer B constituting the hard coating layer of the coated high-speed gear cutting tool 1 to 6 of the present invention, and the hard coating layer of the comparative coated high-speed gear cutting tool 1 to 16 are defined as transmission electron When measured by an energy dispersive X-ray analysis method using a microscope, each showed substantially the same composition as the target composition.
Further, when the layer thickness of each constituent layer of the hard coating layer was measured with a transmission electron microscope, the average value (average value of five locations) was substantially the same as the target layer thickness.

  From the results shown in Tables 1 and 2, the hard coating layer of the coated high-speed gear cutting tool according to the present invention was composed of the alternating layer structure of the thin layer A and the thin layer B, and further the base layer, and the hard coating layer was excellent. High temperature hardness, heat-resistant plastic deformation, excellent high temperature toughness, and high temperature strength. When used under high speed gear cutting conditions with high heat generation and high impact and mechanical load. In addition, while exhibiting excellent wear resistance without occurrence of chipping and chipping, the hard coating layer has a single-phase (Al, Cr, Si) N layer or (Al, Ti, Si). ) The comparative coated high-speed gear cutting tool consisting of N layers has a short service life in a relatively short period of time due to lack of toughness, chipping or chipping, or poor wear resistance, especially under the high-speed gear cutting conditions. It is clear that

As raw material powders, medium coarse WC powder having an average particle diameter of 5.5 μm, fine WC powder of 0.8 μm, TaC powder of 1.3 μm, NbC powder of 1.2 μm, ZrC of 1.2 μm Powder, 2.3 μm Cr ₃ C ₂ powder, 1.5 μm VC powder, 1.0 μm (Ti, W) C [by mass ratio, TiC / WC = 50/50] powder, and 1 .8 μm Co powder was prepared, and each of these raw material powders was blended in the blending composition shown in Table 3, added with wax, ball milled in acetone for 24 hours, dried under reduced pressure, and then in a predetermined shape at a pressure of 100 MPa. The green compacts were press-molded, and these green compacts were heated to a predetermined temperature in the range of 1370 to 1470 ° C. at a rate of temperature increase of 7 ° C./min in a 6 Pa vacuum atmosphere. After holding at temperature for 1 hour, sintering under furnace cooling conditions Three types of cemented carbide substrate-forming round bar sintered bodies having diameters of 8 mm, 13 mm, and 26 mm were formed, and further, the three kinds of round bar sintered bodies were ground and shown in Table 3. In combination, the diameter x length of the cutting edge is 6 mm x 13 mm, 10 mm x 22 mm, and 20 mm x 45 mm, respectively, and each is made of a WC-based cemented carbide with a 4-flute square shape with a twist angle of 30 degrees Carbide end mills 1 to 11 were produced.

  Next, the surfaces of these carbide end mills 3, 4, 7, and 11 were ultrasonically cleaned in acetone and dried, and then placed in the arc ion plating apparatus shown in FIG. Under the same conditions, the lower layer of the target composition and the target layer thickness shown in Table 4 and the thin layer A and the thin layer B of the target composition and the target layer thickness also shown in Table 4 along the layer thickness direction. The surface-coated carbide end mills of the present invention (hereinafter referred to as the present invention-coated carbide end mill) 1 to 4 as the surface-coated cutting tool of the present invention were produced by vapor-depositing the upper layer composed of the laminate.

  Further, for the purpose of comparison, the surfaces of the above-mentioned carbide end mills 1 to 8 were ultrasonically cleaned in acetone and dried, and then inserted into the arc ion plating apparatus shown in FIG. 1. A hard coating layer having a single-phase structure having the target composition and target layer thickness shown in Table 5 under the same conditions as in Table 1 was deposited to produce a comparative surface-coated carbide end mill (hereinafter referred to as a comparative coated carbide end mill). 1 to 11) were produced.

(A) Next, of the present invention coated carbide end mills 1-4 and comparative coated carbide end mills 1-11,
(A1) About the present coated carbide end mills 1 and 2 and comparative coated carbide end mills 1 to 4,
Work material-plane: 100 mm x 250 mm, thickness: 50 mm JIS / SKD61 plate material,
Cutting speed: 150 m / min. ,
Groove depth (cut): 1.0 mm,
Table feed: 1000 mm / min,
A dry high-speed grooving test of the mold steel under the conditions (normal cutting speed is 120 m / min.)
(A2) About this invention coated carbide end mill 3 and comparative coated carbide end mills 5-8,
Work material-plane: 100 mm × 250 mm, thickness: 50 mm JIS / SCM440 plate material,
Cutting speed: 160 m / min. ,
Groove depth (cut): 1.0 mm,
Table feed: 1200 mm / min,
The dry high-speed grooving test of the alloy steel under the conditions (normal cutting speed is 100 m / min.)
(A3) About this invention coated carbide end mill 4 and comparative coated carbide end mills 9-11,
Work material-plane: 100 mm x 250 mm, thickness: 50 mm JIS / SKD11 plate material,
Cutting speed: 100 m / min. ,
Groove depth (cut): 1.0 mm,
Table feed: 600 mm / min,
The dry high speed grooving test (normal cutting speed is 50 m / min.) Of cold die steel under the conditions of
In any of the groove cutting tests of the above (a1) to (a3), the cutting groove length until the flank wear width of the outer peripheral edge of the cutting edge reaches 0.1 mm, which is a guide for the service life, The measurement results are shown in Table 4 and Table 5, respectively.

Three types of high-speed tool steel (JIS / SKH55) materials with a diameter of 8 mm, 13 mm, and 26 mm are prepared. From this material, the diameter x length of the cutting edge is 6 mm x 13 mm by machining. High-speed end mills 1 to 9 each having a four-blade square shape with dimensions of 10 mm × 22 mm and 20 mm × 45 mm and a twist angle of 30 degrees were manufactured.
The dimensions and shapes of the high-speed end mills 1 to 3, 4 to 6, and 7 to 9 are the same as those of the carbide end mills 1 to 4, 5 to 8, and 9 to 11 described in the third embodiment, respectively. .

  Then, the surfaces of these high-speed end mills 3, 6 and 9 were ultrasonically cleaned in acetone and dried, and then charged into the arc ion plating apparatus shown in FIG. Under the conditions, it consists of the lower layer of the target composition and target layer thickness shown in Table 6, and the alternate lamination of the thin layer A and the thin layer B of the target composition and target layer thickness shown in Table 6 along the same layer thickness direction. By forming the upper layer by vapor deposition, the surface-coated high-speed end mills (hereinafter referred to as the present invention-coated high-speed end mills) 1 to 3 as the surface-coated cutting tool of the present invention were produced.

  Further, for the purpose of comparison, the surfaces of the high-speed end mills 1 to 9 were ultrasonically cleaned in acetone and dried, and charged in the arc ion plating apparatus shown in FIG. A comparative surface-coated high-speed end mill (hereinafter referred to as comparative-coated high-speed end mill) 1 is deposited by vapor-depositing a hard coating layer having a single-phase structure with the target composition and target layer thickness shown in Table 7 under the same conditions as in Table 1. ~ 9 were produced respectively.

(B) Next, among the coated high speed end mills 1 to 3 and the comparative coated high speed end mills 1 to 9 of the present invention,
(B1) About this invention coated high speed end mill 1 and comparative coated high speed end mills 1 to 3,
Work material-plane: 100 mm x 250 mm, thickness: 50 mm JIS / S55C plate material,
Cutting speed: 60 m / min. ,
Groove depth (cut): 6 mm,
Table feed: 400 mm / min,
A carbon steel dry high-speed grooving test (normal cutting speed is 30 m / min.),
(B2) About this invention coated high speed end mill 2 and comparative coated high speed end mills 4-6,
Work material-plane: 100 mm x 250 mm, thickness: 50 mm JIS / SKD61 plate material,
Cutting speed: 50 m / min. ,
Groove depth (cut): 10 mm,
Table feed: 400 mm / min,
A die steel dry high-speed grooving test (normal cutting speed is 25 m / min.) Under the conditions of
(B3) About this invention coated high-speed end mill 3 and comparative coated high-speed end mills 7-9,
Work material-plane: 100 mm × 250 mm, thickness: 50 mm JIS / SCM440 plate material,
Cutting speed: 50 m / min. ,
Groove depth (cut): 20 mm,
Table feed: 350 mm / min,
A dry high-speed grooving test of the alloy steel under the conditions (normal cutting speed is 25 m / min.)
In any of the above groove cutting tests (b1) to (b3), the cutting groove length until the flank wear width of the outer peripheral edge of the cutting edge reaches 0.1 mm, which is a guide for the service life, The measurement results are shown in Tables 6 and 7, respectively.

The coated carbide end mills 1 to 4 of the present invention in Example 3, the coated high speed end mill 1 to 3 of the present invention in Example 4, and an upper layer composed of an alternately laminated structure of the thin layer A and the thin layer B constituting the hard coating layer. Furthermore, when the compositions of the hard coating layers of the comparative coated carbide end mills 1 to 11 and the comparative coated high speed end mills 1 to 9 were measured by an energy dispersive X-ray analysis method using a transmission electron microscope, the respective target compositions were obtained. And substantially the same composition.
Further, when the layer thickness of each constituent layer of the hard coating layer was measured with a transmission electron microscope, the average value (average value of five locations) was substantially the same as the target layer thickness.

  From the results shown in Tables 4 to 7, the hard coating layer of the coated carbide end mill of the present invention and the coated high speed end mill of the present invention is composed of an alternating laminated structure of thin layers A and thin layers B and a base layer, and is hard. The coating layer has excellent high-temperature hardness, heat-resistant plastic deformation, excellent high-temperature toughness, and high-temperature strength, so it can be used in high-speed milling with high heat generation and high impact and mechanical load. It exhibits excellent wear resistance without occurrence of chipping and chipping, whereas the hard coating layer has a single-phase (Al, Cr, Si) N layer or (Al, Ti, Si) N Comparison coated carbide end mills and comparison coated high-speed end mills composed of layers are relatively short because, under the high-speed milling conditions, defects, chipping occur due to insufficient toughness, or wear resistance is poor. In it it is clear that through use life.

  The diameters produced in Example 3 above were 6 mm (base symbol A to C of raw material powder for carbide end mill), 10 mm (base symbol D to F of raw material powder for carbide end mill), and 20 mm (raw material for carbide end mill) Using three types of round bar sintered bodies of powder base symbol G, H), from these three types of round bar sintered bodies, all have a four-blade shape with a twist angle of 30 degrees by grinding, And the diameter x length of the groove forming part is 4 mm x 13 mm, respectively. Carbide drills 1 to 4 made of WC base cemented carbide, 8 mm x 22 mm WC base cemented carbide carbide drills 5 to 8, and 16 mm Carbide drills 9 to 11 made of × 45 mm WC-base cemented carbide were produced.

  Then, the cutting edges of these carbide drills 3, 4, 7, and 11 are subjected to honing, ultrasonically cleaned in acetone, and dried, and then loaded into the arc ion plating apparatus shown in FIG. Then, under the same conditions as in Example 1, the lower layer having the target composition and the target layer thickness shown in Table 8 and the thin layer A having the target composition and the target layer thickness shown in Table 8 along the layer thickness direction. The surface-coated carbide drills of the present invention (hereinafter referred to as the present invention-coated carbide drills) 1 to 4 were produced by vapor-depositing and forming upper layers composed of alternating layers of the thin layer B.

  For comparison purposes, the surfaces of the above-described carbide drills 1 to 11 are subjected to honing, ultrasonically cleaned in acetone, and dried, and then loaded into the arc ion plating apparatus shown in FIG. Then, under the same conditions as in Example 1, a hard coating layer having a single phase structure with the target composition and target layer thickness also shown in Table 9 was deposited, so that a comparative surface-coated carbide drill (hereinafter, (Referred to as comparative coated carbide drills) 1 to 11 were produced.

(C) Next, of the present invention coated carbide drills 1-4 and comparative coated carbide drills 1-11,
(C1) About the coated carbide drills 1 and 2 and comparative coated carbide drills 1 to 4 of the present invention,
Work material-plane: 100 mm × 250, thickness: 50 mm plate material of JIS / SKD61 Cutting speed: 50 m / min. ,
Feed: 0.18 mm / rev,
Hole depth: 10 mm,
Wet high-speed drilling test of the alloy tool steel for hot mold under the conditions (normal cutting speed is 35 m / min.),
(C2) About this invention coated carbide drill 3 and comparative coated carbide drills 5-8,
Work material-plane: 100 mm × 250 mm, thickness: 50 mm JIS / SCM440 plate material,
Cutting speed: 85 m / min. ,
Feed: 0.3 mm / rev,
Hole depth: 20 mm,
We performed a wet high-speed drilling test (normal cutting speed is 60 m / min.) Of chromium molybdenum steel under the conditions of
(C3) About this invention coated carbide drill 4 and comparative coated carbide drills 9-11,
Work material-plane: 100 mm x 250 mm, thickness: 50 mm JIS / S55C plate material,
Cutting speed: 110 m / min. ,
Feed: 0.3 mm / rev,
Hole depth: 40 mm,
We performed a high-speed wet drilling test of the carbon steel for machine structure under the conditions (normal cutting speed is 80 m / min.)
In any of the high-speed wet drilling tests (using water-soluble cutting oil) of the above (c1) to (c3), the number of drilling processes until the flank wear width of the tip cutting edge surface reaches 0.3 mm is measured. The measurement results are shown in Table 8 and Table 9, respectively.

As a result, the upper layer and the underlayer, and the comparative coated carbide drills 1 to 11, which are composed of the alternately laminated structure of the thin layers A and B constituting the hard coating layers of the coated carbide drills 1 to 4 of the present invention obtained as a result. When the composition of the hard coating layer was measured by an energy dispersive X-ray analysis method using a transmission electron microscope, each showed substantially the same composition as the target composition.
Further, when the layer thickness of each constituent layer of the hard coating layer was measured with a transmission electron microscope, the average value (average value of five locations) was substantially the same as the target layer thickness.

  From the results shown in Tables 8 and 9, the hard coating layer of the coated carbide drill of the present invention was composed of the alternating layer structure of the thin layer A and the thin layer B and the underlayer, and the hard coating layer was excellent. Because it combines high-temperature hardness and heat-resistant plastic deformation with excellent high-temperature toughness and high-temperature strength, chipping and chipping can be prevented even in high-speed drilling with high heat generation and high impact and mechanical load. A comparative coating consisting of an (Al, Cr, Si) N layer or (Al, Ti, Si) N layer having a single phase structure, while exhibiting excellent wear resistance without occurrence It is apparent that the carbide drill has a service life in a relatively short time because the high-speed drilling conditions are particularly lacking in toughness, resulting in defects, chipping, or poor wear resistance.

As is clear from Examples 1 to 5 above, the surface-coated cutting tool of the present invention (for example, the coated high-speed tooth cutting tool of the present invention, the coated carbide end mill of the present invention, the coated high-speed end mill of the present invention, and the coated ultra-coated tool of the present invention). Hard drills are not only for cutting under normal cutting conditions such as various steels and cast iron, but also for high-speed gear cutting and high-speed milling with high heat generation and high impact and mechanical load. Even in high-speed drilling, it exhibits excellent chipping resistance and wear resistance, and exhibits excellent cutting performance over a long period of time. It is possible to cope with the reduction of cost and cost.

Claims (4)

In a surface-coated cutting tool in which a hard coating layer is formed on the tool base surface,
The hard coating layer is composed of an upper layer having an alternately laminated structure of thin layers A and B, and an underlayer formed between the upper layer and the tool base surface,
The upper layer thin layer A and thin layer B each have a layer thickness of 0.01 to 0.1 μm, and thin layer A and thin layer B have a total layer thickness of 1 to 10 μm, ,
(A) The thin layer A is
Composition formula: When expressed by [Al _X Cr _Y Si _Z ] N,
0.2 ≦ X ≦ 0.45, 0.4 ≦ Y ≦ 0.75, 0.01 ≦ Z ≦ 0.2, and X + Y + Z = 1 (where X, Y, and Z are atomic ratios) are satisfied. A composite nitride layer of Al, Cr and Si;
(B) The thin layer B is
Composition formula: [Al _U Ti _V Si _W ] N
0.05 ≦ U ≦ 0.75, 0.15 ≦ V ≦ 0.94, 0.01 ≦ W ≦ 0.1, U + V + W = 1 (where U, V, and W are atomic ratios) A composite nitride layer of Al, Ti and Si,
The surface-coated cutting tool, wherein the underlayer has a layer thickness of 0.5 to 10 μm and has a composition satisfying the composition formula of the thin layer B.   The surface-coated cutting tool according to claim 1, wherein the surface-coated cutting tool is a gear cutting tool having a high-speed tool steel as a tool base.   The surface-coated cutting tool according to claim 1, wherein the surface-coated cutting tool is an end mill having a high-speed tool steel as a tool base. The surface-coated cutting tool according to claim 1, wherein the surface-coated cutting tool is an end mill or a drill having a tungsten carbide base cemented carbide as a tool base.