JP2008173701A - Surface-coated cutting tool provided with hard coated layer achieving excellent wear resistance in high speed cutting - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface-coated cutting tool provided with a hard coated layer achieving excellent wear resistance in high speed cutting. <P>SOLUTION: This surface-coated cutting tool is constituted by covering a surface of a tool basic body made of tungsten carbide group cemented carbide or titanium carbon nitride group cermet with N layers having average thickness of layers of 1-8 μm and having varying composition (Al, Cr, Ti, Si, W, C) in which the maximum amount of Al-Cr-Ti-Si containing points and the maximum amount of W-C containing points are alternately and repeatedly existent at a predetermined interval along the direction of thickness of layers. The percentages of content of Al, Cr, Ti, Si, W, and C at the maximum amount of Al-Cr-Ti-Si containing point are 0.2-0.4, 0.1-0.25, 0.1-0.25, 0.05-0.1, 0.05-0.3, and 0.05-0.3, respectively, and the percentages of contents of Al, Cr, Ti, Si, W, and C at the maximum amount of W-C containing point are 0.05-0.15, 0.03-0.08, 0.03-0.09, 0.01-0.04, 0.35-0.5, and 0.35-0.5, respectively. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention provides a surface-coated cutting tool (hereinafter referred to as a coated tool) that exhibits excellent wear resistance with a hard coating layer even when various types of steel and cast iron are cut under high-speed cutting conditions with high heat generation. )).

  In general, for coated tools, throwaway inserts that are detachably attached to the tip of the cutting tool for turning and planing of various steel and cast iron materials, drilling of the work material, etc. Drills and miniature drills, and solid type end mills used for chamfering, grooving, shouldering, etc. of the work material, etc. A slow-away end mill tool that performs cutting work in the same manner as an end mill is known.

  As one of the coated tools, Al, Cr, Ti and Si are formed on the surface of a tool base made of tungsten carbide (hereinafter referred to as WC) based cemented carbide or titanium carbonitride (hereinafter referred to as TiCN) based cermet. There is known a coated tool formed by physical vapor deposition of a hard coating layer comprising at least one element selected from N, C, etc., with a metal component mainly composed of a composite nitride layer of The hard coating layer of the coated tool has excellent high temperature hardness, heat resistance and high temperature strength, and excellent cutting performance when used for cutting various general steels and ordinary cast iron under normal conditions. It is known to exert.

Further, the above-mentioned coated tool is loaded with the above-mentioned tool base in an arc ion plating apparatus which is one type of physical vapor deposition apparatus shown schematically in FIG. 2, for example, and the inside of the apparatus is heated at, for example, 550 ° C. In a state where nitrogen gas and / or methane gas was introduced to make a reaction atmosphere of 1.0 Pa and a bias voltage of −120 V was applied to the tool base, Al having a predetermined composition and Al Arc discharge is generated between a cathode electrode (evaporation source) in which an alloy of Cr, Ti, and Si (hereinafter referred to as Al—Cr—Ti—Si) is set, and the Al, It is also known that it is manufactured by vapor-depositing a hard coating layer made of a Cr, Ti, Si nitride, carbide or carbonitride layer.
JP 2004-106183 A

  In recent years, the use of FA for cutting devices has been remarkable. On the other hand, there has been a strong demand for labor saving and energy saving and further cost reduction for cutting processing, and along with this, cutting processing tends to be further accelerated. In a coated tool, there is no problem when it is used for cutting under normal conditions, but when it is used for high-speed cutting conditions with high heat generation, the hard coating layer is caused by the high heat generated during cutting. It is overheated, the wear is accelerated by the temperature rise, and the service life is reached in a relatively short time.

In view of the above, the inventors of the present invention focused on the above-mentioned conventional coated tool in order to develop a coated tool that exhibits excellent wear resistance with a hard coating layer, particularly in high-speed cutting, and researched. As a result of
(B) For example, an (Al, Cr, Ti, Si) N deposition arc ion plating (AIP) apparatus having a structure shown in a schematic plan view in FIG. 1A and a schematic front view in FIG. Using a vapor deposition apparatus equipped with a magnetron sputtering (SP) apparatus for vapor deposition, a rotary table for mounting a tool substrate (for example, a carbide substrate) is provided in the center of the device, and a predetermined value is provided on one side of the rotary table. Arc ion plating apparatus for vapor deposition of (Al, Cr, Ti, Si) N having a cathode electrode (evaporation source) made of an Al—Cr—Ti—Si alloy having a composition, and a target made of a WC sintered body on the other side A magnetron sputtering apparatus for WC vapor deposition equipped with (evaporation source) is arranged opposite to each other, and a plurality of tools are mounted on the rotary table for mounting the tool base at a predetermined distance in the radial direction from the central axis. In this state, the tool base is mounted in a ring shape, and the atmosphere inside the apparatus is changed to a nitrogen atmosphere. The rotary table is rotated, and the tool base itself is rotated for the purpose of uniforming the thickness of the hard coating layer to be formed. , Generating an arc discharge between the cathode electrode (evaporation source) and the anode electrode made of an Al—Cr—Ti—Si alloy of the above-described (Al, Cr, Ti, Si) N vapor deposition arc ion plating apparatus, At the same time, when W and C are sputtered by applying a pulse voltage to a target (evaporation source) made of a WC sintered body of a magnetron sputtering apparatus for WC deposition disposed oppositely, Al and Cr are formed by arc ion plating and sputtering. And a nitride layer of Ti, Si, W and C (hereinafter referred to as (Al, Cr, Ti, Si, W, C) N layers) are formed by vapor deposition. Thus, the nitride layer is relatively deposited at a position where the tool base disposed on the rotary table is closest to the cathode electrode (evaporation source) of the Al-Cr-Ti-Si alloy on the one side. A region where the content ratio of Al, Cr, Ti, Si in the layer is maximized and the content ratio of W and C is minimized (hereinafter referred to as the Al-Cr-Ti-Si maximum content point) is formed, and In the position where the tool base is closest to the WC sintered compact target (evaporation source) on the other side, the content ratio of W and C in the vapor deposition layer is relatively maximized, and Al, Cr, A region where the content ratio of Ti and Si is minimized (hereinafter referred to as the WC maximum content point) is formed, and the Al—Cr—Ti— is formed in the layer along the layer thickness direction by rotation of the rotary table. Si maximum content point and WC maximum content point is the rotation speed of the rotary table Repeatedly appearing at predetermined intervals according to the above, and the highest content point of WC from the highest content point of Al-Cr-Ti-Si, and the highest content of Al-Cr-Ti-Si from the highest content point of WC To the point, a vapor deposition layer having a component concentration distribution structure in which the contents of Al, Cr, Ti, Si, W, and C change continuously (hereinafter, composition change (Al, Cr, Ti, Si, W, C) N A layer) is formed.

(B) In the hard coating layer composed of the above composition change (Al, Cr, Ti, Si, W, C) N layer, the Al component improves high-temperature hardness, heat resistance and oxidation resistance, and the Cr component and Ti component improves high-temperature strength, Si component further improves heat resistance, W component improves heat-resistant plastic deformation, and C component improves film hardness by forming carbide. In addition, the composition change (Al, Cr, Ti, Si, Al, Cr, Ti, Si, W, C) Hard coating layer consisting of N layer has excellent high-temperature hardness, heat resistance, oxidation resistance and high-temperature strength, but on the other hand, because of insufficient heat-resistant plastic deformation and lubricity, high-speed cutting conditions Underneath is uneven wear and Therefore, the composition change (Al, Cr, Ti, Si, W, C) was excellent in order to compensate for the lack of heat plastic deformation and lubricity at the Al-Cr-Ti-Si highest content point of the N layer. Hard coating layer composed of the above composition change (Al, Cr, Ti, Si, W, C) N layer by alternately interposing the WC highest content points having heat plastic deformation and lubricity in the thickness direction Overall, it has excellent high-temperature hardness, heat resistance, oxidation resistance, and high-temperature strength, as well as heat-resistant plastic deformation and lubricity. As a result, it has excellent uneven wear even under high-speed cutting conditions. To exhibit high wear resistance.
The research results shown in (a) and (b) above were obtained.

This invention was made based on the above research results,
Vapor deposition apparatus provided with a tungsten carbide based cemented carbide or titanium carbonitride based cermet, a cathode base electrode with an Al-Cr-Ti-Si alloy on one side, and a target WC sintered material on the other side While rotating the tool base on the rotary table, arc ion plating on the Al-Cr-Ti-Si alloy cathode electrode side and sputtering on the WC sintered material target side while rotating the tool base on the rotary table, In the surface-coated cutting tool in which a hard coating layer composed of a nitride layer of Al, Cr, Ti, Si, W, and C is formed on the surface of the tool base by vapor deposition,
(A) The hard coating layer has an average layer thickness of 1 to 8 μm, and is formed in the vicinity of the Al—Cr—Ti—Si alloy cathode electrode along the layer thickness direction of the hard coating layer. Ti-Si highest content point and WC highest content point formed in the vicinity of the WC sintered material target are alternately present at intervals of 0.005 to 0.1 μm,
(B) From the Al-Cr-Ti-Si highest content point to the WC highest content point, from the WC highest content point to the Al-Cr-Ti-Si highest content point, Al, Cr, Ti , Si, W, and C have a component concentration distribution structure in which the content ratios continuously change,
(C) Al component, Cr component, Ti component, Si component, W component and C component at the Al-Cr-Ti-Si highest content point formed in the vicinity of the Al-Cr-Ti-Si alloy cathode electrode, When the content ratio (however, the atomic ratio) is expressed by X, Y, Z, α, β, γ, X is 0.2 to 0.4, Y is 0.1 to 0.25, Z Is 0.1 to 0.25, α is 0.05 to 0.1, β is 0.05 to 0.3, γ is 0.05 to 0.3, and X + Y + Z + α + β + γ = 1 is satisfied,
(D) Al component, Cr component, Ti component, Si component, W component and C component at the WC highest content point formed in the vicinity of the WC sintered material target, the content ratio (however, atomic ratio) Is represented by X, Y, Z, α, β, γ, respectively, X is 0.05 to 0.15, Y is 0.03 to 0.08, Z is 0.03 to 0.09, α is 0.01 to 0.04, β is 0.35 to 0.5, γ is 0.35 to 0.5, and composition change satisfying X + Y + Z + α + β + γ = 1 (Al, Cr, Ti, Si, W, C) formed by vapor deposition of N layer,
It is characterized by a surface-coated cutting tool (coated tool) that exhibits excellent wear resistance with a hard coating layer in high-speed cutting.

  Next, the reason why the numerical values of the composition change (Al, Cr, Ti, Si, W, C) N layers constituting the hard coating layer of the coated tool of the present invention are limited as described above will be described.

(A) Al, Cr, Ti, Si content ratio of Al-Cr-Ti-Si highest content point Composition change (Al, Cr, Ti, Si, W, C) Al in N layer is high temperature hardness, heat resistance In addition, the Cr component and Ti component improve the high temperature strength, the Si component further improves heat resistance, and the W component increases heat dissipation (thermal conductivity) of the layer and heat resistance plasticity. In addition to improving the deformability, the C component has the effect of improving the film hardness and the lubricity by forming carbides. Therefore, Al-Cr-Ti-Si has a relatively high content ratio of Al, Cr, Ti, and Si components, and has excellent high-temperature hardness, high-temperature strength, heat resistance, and oxidation resistance, but contains Al. When the ratio (X value) is less than 0.2, the high-temperature hardness, heat resistance, and oxidation resistance required as a minimum for the hard coating layer cannot be maintained, and the Cr content ratio (Y value) Is less than 0.1, there is a risk of chipping due to insufficient high-temperature strength, and if the Ti content (Z value) is less than 0.1, the high-temperature strength of the hard coating layer cannot be ensured, When the Si content (α value) is less than 0.05, further improvement in the heat resistance of the hard coating layer cannot be expected. On the other hand, the Al content ratio (X value) exceeds 0.4, the Cr content ratio (Y value) exceeds 0.25, the Ti content ratio (Z value) exceeds 0.25, When the Si content ratio (α value) exceeds 0.1, the W content ratio (β value) and the C content ratio (γ value) become too small, and the heat resistance of the hard coating layer is reduced. Since plastic deformability, film hardness, and lubricity cannot be secured, the Al content ratio (X value) is 0.2 to 0.4, and the Cr content ratio (Y value) is 0.1. The content ratio (Z value) of Ti was set to 0.1 to 0.25, and the content ratio (α value) of Si was set to 0.05 to 0.1 (all in atomic ratio).
Moreover, the content ratio (β value) of the W component and the content ratio (γ value) of the C component at the highest Al—Cr—Ti—Si content point ensure the heat-resistant plastic deformation and lubricity required in high-speed cutting. Therefore, it is necessary to set the ranges of 0.05 ≦ β ≦ 0.3 and 0.05 ≦ γ ≦ 0.3, and X, Y, Z, α, β, and γ are X + Y + Z + α + β + γ = 1. Must be a numerical value satisfying

(B) W and C content ratio of W-C highest content point Composition change (Al, Cr, Ti, Si, W, C) N layer has excellent heat-resistant plastic deformation at the W-C highest content point of the hard coating layer. However, not only these properties but also the high temperature hardness, heat resistance, and high temperature strength required as a minimum for the hard coating layer, the hard coating layer must naturally have the properties, hardness, and lubricity. The W content ratio (β value) and the C content ratio (γ value) at the WC maximum content point are the ratio (atomic ratio) in the total amount of Al, Cr, Ti, Si, W, and C, respectively. .35 to 0.5 and 0.35 to 0.5.
That is, when the W content ratio (β value) exceeds 0.5 or the C content ratio (γ value) exceeds 0.5, the (Al, Cr, Ti, Si, W, C) in the N layer As a result, the high temperature hardness, high temperature strength, and heat resistance are insufficient, and chipping (minute chipping) is likely to occur on the cutting edge, When the W content ratio (β value) is less than 0.35, or when the C content ratio (γ value) is less than 0.35, W in the (Al, Cr, Ti, Si, W, C) N layer , Since the content ratio of C becomes too small and improvement in heat-resistant plastic deformability, hardness, and lubricity cannot be expected, the W content ratio (β value) is 0.35 to 0.5, The content ratio (γ value) of C was set to 0.35 to 0.5 (all are atomic ratios).
In addition, the content ratio (X value) of the Al component at the WC highest content point, the content ratio (Y value) of the Cr component, the content ratio (Z value) of the Ti component, and the content ratio (α value) of the Si component are: 0.05 ≦ X ≦ 0.15, 0.03 ≦ Y ≦ 0.08, 0.03 ≦ Z ≦ to ensure the high temperature hardness, high temperature strength and heat resistance required at the minimum for high speed cutting 0.09, 0.01 ≦ α ≦ 0.04, and X, Y, Z, α, β, and γ must be values satisfying X + Y + Z + α + β + γ = 1.

(C) Spacing between Al-Cr-Ti-Si highest content point and WC highest content point In the hard coating layer of this invention, the concentration of the component constituting the nitride is Al in the layer thickness direction. -It changes continuously from the highest content point of Cr-Ti-Si to the highest content point of WC and from the highest content point of WC to the highest content point of Al-Cr-Ti-Si, For example, compared to a hard coating layer consisting of a multi-layered structure in which the component concentration changes rapidly and discontinuously, there is no risk of delamination between multiple layers, and the adhesion strength and bonding strength of the hard coating layer itself are very high. It is excellent. However, if the distance between the Al—Cr—Ti—Si highest content point and the WC highest content point is less than 0.005 μm, it is difficult to clearly form each point with the above composition. The desired high-temperature hardness, high-temperature strength, heat resistance, oxidation resistance, heat-resistant plastic deformation and lubricity cannot be ensured in the layer, and the disadvantages of each point when the interval exceeds 0.1 μm, That is, if the W-C highest content point, insufficient high-temperature hardness, high-temperature strength, oxidation resistance and heat resistance, and if Al-Cr-Ti-Si highest content point, insufficient heat-resistant plastic deformation and lubricity Appears locally in the layer, and this makes it easier for chipping to occur on the cutting edge and promotes the progress of wear, so the interval was set to 0.005 to 0.1 μm. .
In addition, the space | interval between the Al-Cr-Ti-Si highest content point and the WC highest content point is the arc ion plating (AIP) apparatus for (Al, Cr, Ti, Si) N vapor deposition, and WC vapor deposition. When using a vapor deposition device with a magnetron sputtering (SP) device to form a vapor deposition film by simultaneously performing arc ion plating and sputtering, for example, by adjusting the rotation speed of the rotary table equipped with the tool base Therefore, by appropriately setting the rotation speed of the turntable, the interval between the Al—Cr—Ti—Si highest content point and the WC highest content point becomes a desired value within the above numerical range. Compositional change (Al, Cr, Ti, Si, W, C) N layers can be easily formed.

(D) Average layer thickness If the average layer thickness is less than 1 μm, the hard coating layer should ensure the desired high temperature hardness, high temperature strength, heat resistance, oxidation resistance, heat plastic deformation and lubricity over a long period of time. As a result, improvement in wear resistance in high-speed cutting cannot be expected. On the other hand, if the average layer thickness exceeds 8 μm, chipping tends to occur on the cutting edge. The thickness was set to 1-8 μm.

  In the coated tool of the present invention, the composition change (Al, Cr, Ti, Si, W, C) N layer constituting the hard coating layer as a whole has excellent high-temperature hardness, high-temperature strength, heat resistance, and oxidation resistance. In addition, it has excellent heat-resistant plastic deformation and lubricity, so that various steels and cast irons can be used for a long time even when processed under high-speed cutting conditions with particularly large heat generation. Exhibits excellent wear resistance.

  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 in 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, after sintering, WC-based carbide with honing of R: 0.03 on the cutting edge and chip shape of ISO standard CNMG120408 Alloy tool bases A-1 to A-10 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 The green compact was sintered in a nitrogen atmosphere of 2 kPa at a temperature of 1500 ° C. for 1 hour. After sintering, the cutting edge portion was subjected to a honing process of R: 0.03 to meet ISO standards / Tool bases B-1 to B-6 made of TiCN base cermet having a chip shape of CNMG120408 were formed.

Next, each of the tool bases A1 to A10 and B1 to B6 is ultrasonically cleaned in acetone and dried, and the inside of the vapor deposition apparatus provided with the arc ion plating apparatus and the magnetron sputtering apparatus shown in FIG. The Al—Cr—Ti—Si alloy having various component compositions as the cathode electrode (evaporation source) of the arc ion plating apparatus on one side, A WC sintered body is mounted as a target (evaporation source) of a magnetron sputtering apparatus, and a metal Ti for bombard cleaning is also mounted. First, the apparatus is evacuated and kept at a vacuum of 0.5 Pa or less while the apparatus is heated with a heater. Is heated to 500 ° C., and then a DC bias voltage of −1000 V is applied to the tool base that rotates while rotating on the rotary table. Applied to, by passing a 100A current between said metallic Ti and the anode electrode of the cathode electrode to generate arc discharge, a tool substrate surface was washed Ti bombardment with,
(B) Next, nitrogen gas is introduced as a reaction gas into the apparatus to form a reaction atmosphere of 2 Pa, and a DC bias voltage of −100 V is applied to the tool base that rotates while rotating on the rotary table, and the cathode An arc discharge is generated by passing a current of 90 A between the electrode and the anode electrode,
(C) At the same time, a pulse voltage of 10A and 430V is applied to the target of the WC sintered body using a pulse power source to sputter WC,
(D) Al—Cr—Ti—Si highest content points and WC highest content points of the target compositions shown in Tables 3 and 4 are alternately placed on the surface of the tool base that rotates while rotating on the rotary table. And repeatedly present at the target intervals shown in Tables 3 and 4, and from the Al-Cr-Ti-Si highest content point to the WC highest content point, from the WC highest content point to the Al- It has a component concentration distribution structure in which the content ratio of Al, Cr, Ti, Si, W, and C continuously changes to the highest content point of Cr—Ti—Si, and is also shown in Tables 3 and 4 Composition change of target layer thickness (Al, Cr, Ti, Si, W, C) By depositing a hard coating layer composed of an N layer, the present invention coated tools 1 to 16 having a throwaway tip shape defined in ISO / CNMG120408 Were manufactured respectively.
In addition, in the said Example, the target space | interval of the Al-Cr-Ti-Si highest content point and the WC highest content point changes the rotational speed of a rotary table within the range of 0.5-10 rpm, Adjustments were made to achieve a predetermined target interval value.

  Further, for the purpose of comparison, these tool bases A1 to A10 and B1 to B6 were ultrasonically cleaned in acetone and dried, and each was charged into a normal arc ion plating apparatus shown in FIG. As the cathode electrode (evaporation source), an Al—Cr—Ti—Si—W alloy having various component compositions is mounted, and a bombard cleaning metal Ti is also mounted, and the inside of the apparatus is evacuated to 0.5 Pa or less. While maintaining the vacuum, the inside of the apparatus was heated to 500 ° C. with a heater, a DC bias voltage of −1000 V was applied to the tool base, and a current of 100 A was applied between the metal Ti of the cathode electrode and the anode electrode. To generate arc discharge, and the surface of the tool substrate is cleaned by Ti bombardment. Then, a mixed gas of nitrogen gas and methane gas is introduced into the apparatus as a reaction gas, and 2 Pa of In addition, the bias voltage applied to the tool base is lowered to −100 V, and a current of 90 A is caused to flow between the cathode electrode and the anode electrode to generate arc discharge, whereby the tool bases A1 to A10 are generated. And a hard coating comprising a compositionally uniform (Al, Cr, Ti, Si, W, C) N layer having a target composition and a target layer thickness shown in Tables 5 and 6 on each of B1 and B6 By depositing the layers, comparative coated tools 1 to 16 having the same throwaway tip shape were produced.

Next, in the state where each of the above various coated chips is screwed to the tip of the tool steel tool with a fixing jig, the present coated chips 1-16 and the comparative coated chips 1-16,
Work material: JIS / SCM445 round bar,
Cutting speed: 230 m / min. ,
Incision: 2 mm,
Feed: 0.3 mm / rev. ,
Cutting time: 18 minutes,
Dry high-speed continuous cutting test of alloy steel under the following conditions (cutting condition A) (normal cutting speed is 170 m / min.),
Work material: JIS / S55C round bar,
Cutting speed: 180 m / min. ,
Incision: 2.3 mm,
Feed: 0.5 mm / rev. ,
Cutting time: 15 minutes,
Dry high-speed continuous cutting test of carbon steel under the conditions (cutting condition B) (normal cutting speed is 130 m / min.),
Work material: JIS / SUS347 lengthwise equidistant 4 round grooved round bars,
Cutting speed: 130 m / min. ,
Cutting depth: 2.5 mm,
Feed: 0.3 mm / rev. ,
Cutting time: 8 minutes,
The dry high-speed intermittent cutting test (normal cutting speed is 100 m / min.) Of stainless steel under the above conditions (cutting condition C), and the flank wear width of the cutting edge was measured in any cutting test. . The measurement results are shown in Table 7.

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 Prepare 8 μm Co powder, mix these raw material powders with the composition shown in Table 8, add wax, ball mill in acetone for 24 hours, dry under reduced pressure, and press 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 Then, three types of round rod sintered bodies for forming a tool base having diameters of 8 mm, 13 mm, and 26 mm are formed, and further, the three types of round bar sintered bodies are ground and are shown in Table 7. 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 Tool bases (end mills) C-1 to C-8 were produced.

  Next, the surfaces of these tool substrates (end mills) C-1 to C-8 were ultrasonically cleaned in acetone and dried, and the arc ion plating apparatus and magnetron sputtering apparatus shown in FIG. 1 were also provided. The Al-Cr-Ti-Si highest content point and the WC highest content point of the target composition shown in Table 9 along the layer thickness direction were charged in the same conditions as in Example 1 above. Alternatingly, it repeatedly exists at the target intervals shown in Table 9, and from the Al—Cr—Ti—Si highest content point to the WC highest content point, from the WC highest content point to the Al—Cr— It has a component concentration distribution structure in which the content ratio of Al, Cr, Ti, Si, W, and C continuously changes to the Ti-Si highest content point, and the compositional change of the target layer thickness also shown in Table 9 (Al, Cr, Ti, S , W, C) by deposition form a hard coating layer consisting of N layers, the present invention coated end mills 1-8 as the present invention coated tool was produced, respectively.

  Further, for the purpose of comparison, the surface of the tool base (end mill) C-1 to C-8 is ultrasonically cleaned in acetone and dried, and the ordinary arc ion plating apparatus shown in FIG. Under the same conditions as in Example 1 above, the surfaces of the tool bases (end mills) C-1 to C-8 were uniformly compositionally provided with the target composition and target layer thickness shown in Table 10. Comparative coating end mills 1 to 8 as comparative coating tools were manufactured by vapor-depositing a hard coating layer composed of (Al, Cr, Ti, Si, W, C) N layers.

Next, of the present invention coated end mills 1-8 and comparative coated end mills 1-8,
About this invention coated end mills 1-3 and comparative coated end mills 1-3,
Work material-Plane dimensions: 100 mm x 250 mm, thickness: 50 mm JIS / SNC836 plate material,
Cutting speed: 100 m / min. ,
Groove depth (cut): 10 mm,
Table feed: 420 mm / min,
Dry high-speed grooving test of alloy steel under the conditions (normal cutting speed is 80 m / min.),
About this invention coated end mills 4-6 and comparative coated end mills 4-6,
Work material-planar dimensions: 100 mm x 250 mm, thickness: 50 mm JIS / FCD450 plate material,
Cutting speed: 150 m / min. ,
Groove depth (cut): 13 mm,
Table feed: 350 mm / min,
Cast iron dry high-speed grooving test (normal cutting speed is 100 m / min.),
For the coated end mills 7 and 8 and the comparative coated end mills 7 and 8 of the present invention,
Work material-Plane dimensions: 100 mm x 250 mm, thickness: 50 mm JIS / SCW480 plate material,
Cutting speed: 120 m / min. ,
Groove depth (cut): 15 mm,
Table feed: 600 mm / min,
Test of dry high-speed grooving of cast steel under normal conditions (normal cutting speed is 85 m / min.)
In each of the groove cutting tests, the cutting groove length was measured until the flank wear width of the outer peripheral edge of the cutting edge reached 0.15 mm, which is a guide for the service life. The measurement results are shown in Tables 9 and 10, respectively.

  The diameters produced in Example 2 above were 8 mm (for forming the tool bases C-1 to C-3), 13 mm (for forming the tool bases C-4 to C-6), and 26 mm (tool bases C-7 and C). -8 for forming), and from these three types of round bar sintered bodies, the diameter x length of the groove forming part is 4 mm x 13 mm (tool base D) by grinding. −1 to D-3), 8 mm × 22 mm (tool base D-4 to D-6), and 16 mm × 45 mm (tool bases D-7 and D-8), and all having a twist angle of 30 degrees 2 WC-base cemented carbide tool bases (drills) D-1 to D-8 having a single-blade shape were produced, respectively.

Then, the cutting edges of these tool bases (drills) D-1 to D-8 are subjected to honing, ultrasonically cleaned in acetone, and dried, and the arc ion plating apparatus shown in FIG. A vapor deposition apparatus equipped with a magnetron sputtering apparatus was inserted, and under the same conditions as in Example 1 above, the Al-Cr-Ti-Si highest content point and W- of the target composition shown in Table 11 along the layer thickness direction. The C highest content point is alternately present repeatedly at the target intervals shown in Table 11, and the WC highest content point, the WC highest content point, from the Al-Cr-Ti-Si highest content point. From the Al-Cr-Ti-Si highest content point, the content ratio of Al, Cr, Ti, Si, W, C has a component concentration distribution structure that continuously changes, and is also shown in Table 11 Change in composition of target layer thickness Al, Cr, Ti, Si, W, by depositing form a hard coating layer made of C) N layer, the present invention coated drill 1-8 as the present invention coated tool was produced, respectively.

  For comparison purposes, the surfaces of the above-mentioned tool bases (drills) D-1 to D-8 are subjected to honing, ultrasonically cleaned in acetone, and dried, as shown in FIG. The sample was charged into an arc ion plating apparatus, and had the target composition and target layer thickness shown in Table 12 on the surfaces of the tool bases (drills) D-1 to D-8 under the same conditions as in Example 1. Comparative coating drills 1 to 8 as comparative coating tools were manufactured by vapor-depositing a hard coating layer composed of a compositionally uniform (Al, Cr, Ti, Si, W, C) N layer.

Next, of the present invention coated drills 1-8 and comparative coated drills 1-8,
About this invention coated drills 1-3 and comparative coated drills 1-3,
Work material-Plane dimensions: 100 mm x 250 mm, thickness: 50 mm JIS / SUS434 plate material,
Cutting speed: 80 m / min. ,
Feed: 0.2 mm / rev,
Hole depth: 8 mm,
Wet high-speed drilling test of stainless steel under normal conditions (normal cutting speed is 45 m / min.),
About this invention coated drill 4-6 and comparative coated drill 4-6,
Work material-planar dimensions: 100 mm × 250 mm, thickness: 50 mm JIS / SF490A plate material,
Cutting speed: 120 m / min. ,
Feed: 0.3 mm / rev,
Hole depth: 15 mm,
Wet high-speed drilling test of carbon steel under the conditions (normal cutting speed is 70 m / min.),
About this invention covering drills 7 and 8 and comparative covering drills 7 and 8,
Work material-Plane dimensions: 100 mm x 250 mm, thickness: 50 mm JIS / SNCM420H plate material,
Cutting speed: 160 m / min. ,
Feed: 0.35 mm / rev,
Hole depth: 30 mm,
Wet high-speed drilling test of alloy steel under the conditions of (normal cutting speed is 85 m / min.),
In each wet high-speed drilling test (using water-soluble cutting oil), the number of drilling processes until the flank wear width of the tip cutting edge surface reached 0.35 mm was measured. The measurement results are shown in Tables 11 and 12, respectively.

As a result, the composition changes (Al, Cr, Ti) constituting the hard coating layers of the present coated tips 1-16, the present coated end mills 1-8, and the present coated drills 1-8 as the present coated tools obtained as a result of the present invention. , Si, W, C) The composition of the Al—Cr—Ti—Si highest content point and the W—C highest content point of the N layer was measured by energy dispersive X-ray analysis using a transmission electron microscope. The composition showed substantially the same composition as the Al-Cr-Ti-Si highest content point and WC highest content point of the target composition, respectively. Further, compositionally uniform (Al, Cr, Ti, Si, W) constituting the hard coating layers of the comparative coating tips 1 to 16, the comparative coating end mills 1 to 8, and the comparative coating drills 1 to 8 as comparative coating tools. , C) The composition of the N layer was measured by an energy dispersive X-ray analysis method using a transmission electron microscope, and showed substantially the same composition as the target composition.

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

  From the results shown in Tables 7 and 9 to 12, the coated tool of the present invention is a composition that forms a hard coating layer even when it is used for cutting under high-speed conditions with high heat generation such as steel and cast iron. Change (Al, Cr, Ti, Si, W, C) N layer as a whole has excellent high temperature hardness, high temperature strength, heat resistance, oxidation resistance, and excellent heat plastic deformation and lubricity Therefore, the hard coating layer is composed of a compositionally uniform (Al, Cr, Ti, Si, W, C) N layer while exhibiting excellent wear resistance over a long period of time. In the comparative coated tool, it is clear that uneven wear or the like occurs due to high heat generation in high-speed cutting, which leads to a service life in a relatively short time.

  As described above, the coated tool of the present invention exhibits excellent wear resistance over a long period of time even when used for high-speed cutting with high heat generation, as well as cutting of general steel and ordinary cast iron. However, since it shows excellent cutting performance, it can satisfactorily cope with the FA of the cutting device, the labor saving and energy saving of the cutting work, and the cost reduction.

The vapor deposition apparatus which used together the arc ion plating apparatus and magnetron sputtering apparatus which were used for forming the hard coating layer which comprises the coating tool of this invention is shown, (a) is a schematic plan view, (b) is a schematic front view. It is. It is a schematic explanatory drawing of the normal arc ion plating apparatus used in forming the hard coating layer which comprises a comparative coating tool.

Claims (1)

Vapor deposition apparatus comprising a tungsten carbide-based cemented carbide or a titanium carbonitride-based cermet, an Al—Cr—Ti—Si alloy as a cathode electrode on one side, and a WC sintered material as a target on the other side While rotating the tool base on the rotary table, arc ion plating on the Al-Cr-Ti-Si alloy cathode electrode side and sputtering on the WC sintered material target side while rotating the tool base on the rotary table, In the surface-coated cutting tool in which a hard coating layer composed of a nitride layer of Al, Cr, Ti, Si, W, and C is formed on the surface of the tool base by vapor deposition,
(A) The hard coating layer has an average layer thickness of 1 to 8 μm, and is formed in the vicinity of the Al—Cr—Ti—Si alloy cathode electrode along the thickness direction of the hard coating layer. Ti-Si highest content point and WC highest content point formed in the vicinity of the WC sintered material target are alternately present at intervals of 0.005 to 0.1 μm,
(B) From the Al-Cr-Ti-Si highest content point to the WC highest content point, from the WC highest content point to the Al-Cr-Ti-Si highest content point, Al, Cr, Ti , Si, W, and C have a component concentration distribution structure in which the content ratios continuously change,
(C) Al component, Cr component, Ti component, Si component, W component and C component at the Al-Cr-Ti-Si highest content point formed in the vicinity of the Al-Cr-Ti-Si alloy cathode electrode, When the content ratio (however, the atomic ratio) is expressed by X, Y, Z, α, β, γ, X is 0.2 to 0.4, Y is 0.1 to 0.25, Z Is 0.1 to 0.25, α is 0.05 to 0.1, β is 0.05 to 0.3, γ is 0.05 to 0.3, and X + Y + Z + α + β + γ = 1 is satisfied,
d) Al component, Cr component, Ti component, Si component, W component, and C component at the WC highest content point formed in the vicinity of the WC sintered material target, the content ratio (however, the atomic ratio) , X, Y, Z, α, β, and γ, respectively, X is 0.05 to 0.15, Y is 0.03 to 0.08, Z is 0.03 to 0.09, α Is 0.01 to 0.04, β is 0.35 to 0.5, γ is 0.35 to 0.5, and composition change satisfying X + Y + Z + α + β + γ = 1 (Al, Cr, Ti, Si, W , C) N layer is formed by vapor deposition.
Surface coated cutting tool that exhibits high wear resistance with a hard coating layer in high speed cutting.

Images