JP2008006573A - Surface coated cutting tool having hard coated layer exhibiting excellent wear resistance in high speed cutting of heat resistant alloy - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface coated cutting tool having a hard coated layer exhibiting excellent wear resistance in high speed cutting of a heat resistant alloy. <P>SOLUTION: In this surface coated cutting tool, a composition changing (Al, Ti, Cr, B)N layer having average layer thickness of 1 to 8μm and Al-Ti maximum containing point and Cr-B maximum containing point existing alternately and repeatedly at prescribed intervals along a layer thickness direction is coated on a surface of a tool base body made of tungsten carbide based cemented carbide or titanium carbonitride based cermet. Content ratios of Al, Ti, Cr and B at the Al-Ti maximum containing point are 0.40 to 0.60, 0.30 to 0.50, 0.01 to 0.10 and 0.01 to 0.10, respectively. Content ratios of Al, Ti, Cr and B at the Cr-B maximum containing point are 0.05 to 0.20, 0.05 to 0.20, 0.25 to 0.40, and 0.40 to 0.55, respectively. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  In the present invention, even when heat-resistant alloys such as Ti-base alloys, Ni-base alloys, and Co-base alloys are cut under high-speed cutting conditions with high heat generation, the hard coating layer exhibits excellent wear resistance. The present invention relates to a surface-coated cutting tool (hereinafter referred to as a coated tool).

  In general, for coated tools, throwaway inserts that can be used detachably attached to the tip of a cutting tool for turning and planing of various steel and cast iron, 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, 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,
Has a layer thickness of 1 to 8 .mu.m, the composition _{formula: (Al X Ti Y Cr Q} B R) N ( provided that an atomic ratio, X = 0.5~0.8, Y = 1 -X-Q-R , Q ≧ 0.06, R ≦ 0.1) is known, and a coated tool formed by physical vapor deposition is known, and a hard coated layer of the coated tool [hereinafter referred to as (Al, The Ti, Cr, B) N layer] is known to exhibit excellent wear resistance when used for cutting high-hardness steel such as alloy tool steel under normal conditions.

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. The anode electrode and a cathode electrode (evaporation source) in which an alloy of Al, Ti, Cr and B (hereinafter referred to as Al-Ti-Cr-B alloy) having a predetermined composition is set. In the meantime, for example, an arc discharge is generated under the condition of current: 100 A, and at the same time, nitrogen gas is introduced into the apparatus as a reaction gas to obtain a reaction atmosphere of 2.66 Pa, for example. It is also known that it is manufactured by vapor-depositing a hard coating layer composed of the (Al, Ti, Cr, B) N layer on the surface of the tool base under the condition that a bias voltage of −200 V is applied. That.
JP 2003-71611 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 the case of a coated tool, there is no problem when it is used for cutting under normal conditions, but this is particularly suitable for high-speed cutting of heat-resistant alloys such as Ti-base alloys, Ni-base alloys, and Co-base alloys with high heat generation. When used, the hard coating layer is overheated by the high heat generated during cutting, resulting in insufficient lubricity and welding, thus promoting the progress of wear and reaching the service life in a relatively short time. is the current situation.

In view of the above, the inventors of the present invention have a hard coating layer with excellent wear resistance especially in high-speed cutting processing of heat-resistant alloys such as Ti-base alloys, Ni-base alloys, and Co-base alloys. As a result of conducting research while focusing on the above-mentioned conventional coated tools in order to develop tools,
(A) For example, an (Al, Ti) N deposition arc ion plating (AIP) apparatus and a Cr-B deposition structure having a structure shown in FIG. 1 (a) in a schematic plan view and in FIG. Using a vapor deposition apparatus provided with a magnetron sputtering (SP) apparatus, a rotary table for mounting a tool substrate (for example, a carbide substrate) is provided in the central portion of the apparatus, and an Al− having a predetermined composition is placed on one side of the rotary table. Arc ion plating apparatus for (Al, Ti) N vapor deposition provided with cathode electrode (evaporation source) made of Ti alloy, Cr—B vapor deposition provided with target (evaporation source) made of CrB ₂ sintered body on the other side A plurality of tool substrates are mounted in a ring shape on a rotary table for mounting a tool substrate on a rotary table for mounting the tool substrate at a position spaced apart from the central axis in a radial direction. In this state, the atmosphere in 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, while the (Al, Ti) An arc discharge is generated between the cathode electrode (evaporation source) and the anode electrode made of an Al-Ti alloy of an N deposition arc ion plating apparatus, and at the same time, a Cr-B deposition magnetron sputtering apparatus disposed opposite to each other. When a pulse voltage is applied to a target (evaporation source) made of a CrB ₂ sintered body and CrB ₂ is sputtered, a nitride layer of Al, Ti, Cr and B (hereinafter referred to as (Al, Ti, Cr, B) N)) is deposited, and the nitride layer is formed by a tool substrate disposed on a turntable. In the position closest to the cathode electrode (evaporation source) of the Al-Ti alloy on one side, the content ratio of Al and Ti in the vapor deposition layer is relatively maximum, and the content ratio of Cr and B is minimum A region (hereinafter referred to as Al-Ti highest content point) is formed, and the tool base is relatively close to the other side of the CrB ₂ sintered body target (evaporation source), A region where the content ratio of Cr and B in the vapor deposition layer is maximized and the content ratio of Al and Ti is minimum (hereinafter referred to as the Cr-B maximum content point) is formed, and the rotation table rotates the layer. In the layer thickness direction, the Al-Ti highest content point and the Cr-B highest content point repeatedly appear alternately with a predetermined interval according to the rotation speed of the rotary table, and from the Al-Ti highest content point Cr-B highest content point, before A vapor deposition layer having a component concentration distribution structure in which the content of Al, Ti, Cr, and B continuously changes from the highest content point of Cr-B to the highest content point of Al-Ti (hereinafter referred to as composition change (Al, Ti, Cr, B) N layer) is formed.

(B) In the hard coating layer composed of the above-mentioned composition change (Al, Ti, Cr, B) N layer, the Al component improves the high temperature hardness, heat resistance and oxidation resistance, and the Ti component improves the high temperature strength. Furthermore, the Cr component further improves the high-temperature strength, and the B component has the effect of lowering the reactivity with the work material and at the same time improving the lubricity, and therefore relatively containing Al and Ti. At a high Al-Ti highest content point, the hard coating layer composed of the above-mentioned composition change (Al, Ti, Cr, B) N layer has excellent high-temperature hardness, heat resistance, oxidation resistance and predetermined high-temperature strength. However, since the reactivity with the work material is high and the lubricity is insufficient, welding and uneven wear are likely to occur under high-speed cutting conditions. Therefore, the composition change (Al, Ti, Cr, B) Moisture at the highest Al-Ti content point of the N layer In order to compensate for the lack of reactivity and non-reactivity, the above composition is obtained by alternately interposing the highest content points of Cr-B with higher temperature strength, superior lubricity and non-reactivity in the thickness direction. As a whole hard coating layer composed of modified (Al, Ti, Cr, B) N layers, it has excellent high temperature hardness, heat resistance, oxidation resistance, high temperature strength, lubricity and non-reactivity. As a result, even when cutting heat-resistant alloys under high-speed conditions, excellent wear resistance is exhibited without causing welding, uneven wear, or the like.
The research results shown in (a) and (b) above were obtained.

This invention was made based on the above research results,
A rotary table of a vapor deposition apparatus in which a tungsten carbide-based cemented carbide or titanium carbonitride-based cermet is provided with an Al—Ti alloy as a cathode electrode on one side and a CrB ₂ sintered material as a target on the other side. While the tool base is rotated on a rotary table, Al and Ti are sputtered on the Al—Ti alloy cathode electrode side and sputtering on the CrB ₂ sintered material target side, and Al and In a surface-coated cutting tool in which a hard coating layer composed of a nitride layer of Ti, Cr and B is formed by vapor deposition,
(A) The hard coating layer has an average layer thickness of 1 to 8 μm, and the Al-Ti highest content point formed in the vicinity of the Al-Ti alloy cathode electrode along the thickness direction of the hard coating layer and the The Cr-B highest content point formed in the vicinity of the CrB ₂ sintered material target is alternately and repeatedly present at an interval of 0.005 to 0.1 μm,
(B) The content ratio of Al, Ti, Cr, B is continuous from the highest Al-Ti content point to the highest Cr-B content point and from the highest Cr-B content point to the highest Al-Ti content point. Has a component concentration distribution structure that changes periodically,
(C) The Al component, Ti component, Cr component, and B component at the Al-Ti highest content point formed in the vicinity of the Al-Ti alloy cathode electrode are X, When represented by Y, Q, and R, X is 0.40 to 0.60, Y is 0.30 to 0.50, Q is 0.01 to 0.10, and R is 0.01 to 0.10. And satisfies X + Y + Q + R = 1,
(D) The Al component, Ti component, Cr component, and B component at the highest Cr-B content point formed in the vicinity of the CrB ₂ sintered material target are X, When represented by Y, Q, and R, X is 0.05 to 0.20, Y is 0.05 to 0.20, Q is 0.25 to 0.40, and R is 0.40 to 0.55. And a composition change (Al, Ti, Cr, B) N layer satisfying X + Y + Q + R = 1 is formed by vapor deposition.
It is characterized by a coated tool (surface coated cutting tool) that exhibits excellent wear resistance with a hard coating layer in high-speed cutting of a heat-resistant alloy.

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

(A) Al and Ti content at the highest Al-Ti content point Al (Ti, Cr, B) Al in the N layer improves high temperature hardness, heat resistance and oxidation resistance, and Ti is high temperature Strength is improved, the Cr component further increases the high temperature strength, and the B component has the effect of lowering the reactivity with the work material and at the same time improving the lubricity, and therefore relatively Al and Ti components. When the Al-Ti highest content point is high, it has excellent high-temperature hardness, heat resistance, oxidation resistance and predetermined high-temperature strength, but when the Al content rate (X value) is less than 0.40 The minimum required high-temperature hardness, heat resistance, and oxidation resistance for a hard coating layer cannot be maintained, and if the Ti content (Y value) is less than 0.30, the high-temperature strength is insufficient. There is a risk of chipping due to the presence of Al. When the ratio (X value) exceeds 0.60 or the Ti content ratio (Y value) exceeds 0.50, the Cr content ratio (Q value) and the B content ratio (R Value) becomes too small to reduce the reactivity of the hard coating layer and improve the lubricity, so the Al content ratio (X value) is 0.40 to 0.60, Ti content The ratio (Y value) was set to 0.30 to 0.50.
In addition, the content ratio (Q value) of the Cr component and the content ratio (R value) of the B component at the Al-Ti highest content point are the high-temperature hardness, heat resistance, and oxidation resistance required for high-speed cutting of the heat-resistant alloy. In order to obtain a predetermined high-temperature strength, non-reactivity, and lubricity without damage, it is necessary to set the ranges of 0.01 ≦ Q ≦ 0.10 and 0.01 ≦ R ≦ 0.10, respectively. , X, Y, Q, and R must be numerical values satisfying X + Y + Q + R = 1.

(B) Cr and B content ratio of Cr-B highest content point At the Cr-B highest content point of the hard coating layer, composition change (Al, Ti, Cr, B) N layer has excellent non-reactivity and lubricity. However, the hard coating layer must have not only these properties but also the minimum required high temperature hardness, heat resistance, oxidation resistance, and high temperature strength as the hard coating layer. The Cr content ratio (Q value) and B content ratio (R value) at the content point are ratios (atomic ratios) to the total amount of Al, Ti, Cr, and B, 0.25 to 0.40, 0, respectively. .40-0.55.
That is, when the Cr content ratio (Q value) exceeds 0.40 or the B content ratio (R value) exceeds 0.55, Al, Ti in the (Al, Ti, Cr, B) N layer As a result, the content of components decreases, resulting in insufficient high-temperature hardness, heat resistance, high-temperature strength, and oxidation resistance, and chipping (minute chipping) is likely to occur on the cutting edge. When the Q value is less than 0.25, or when the B content (R value) is less than 0.40, the Cr and B content in the (Al, Ti, Cr, B) N layer decreases. After that, it is impossible to expect a further improvement in high-temperature strength, a reactivity reduction effect and a lubricity improvement effect, so the Cr content ratio (Q value) is 0.25 to 0.40, The content ratio (R value) was set to 0.40 to 0.55 (both atomic ratios).
In addition, the content ratio (X value) of the Al component and the content ratio (Y value) of the Ti component at the Cr-B highest content point are the minimum required high-temperature hardness, heat resistance, and acid resistance for high-speed cutting of heat-resistant alloys. From the viewpoint of chemical properties, it is necessary that the range is 0.05 ≦ X ≦ 0.20, 0.05 ≦ Y ≦ 0.20, and X and Y must be values satisfying X + Y + Q + R = 1. I must.

(C) Interval between Al-Ti highest content point and Cr-B highest content point The hard coating layer of this invention has a concentration of the component constituting the nitride in the layer thickness direction so that the highest content of Al-Ti is contained. Since the point continuously changes from the Cr-B highest content point and from the Cr-B highest content point to the Al-Ti highest content point, for example, a plurality of component concentrations change discontinuously. Compared to a hard coating layer composed of a laminated structure of layers, there is no risk of peeling between multiple layers, and the adhesion strength and bonding strength of the hard coating layer itself are very good, but the Al-Ti highest content point If the distance between the Cr-B highest content points is less than 0.005 μm, it is difficult to clearly form each point with the above composition. As a result, the desired high-temperature hardness, heat resistance, and high-temperature strength for each layer. Ensure oxidation resistance, non-reactivity and lubricity If the distance exceeds 0.1 μm, the disadvantages of the respective points, that is, if the Cr-B highest content point, insufficient high-temperature hardness, heat resistance and oxidation resistance, and Al-Ti highest If it is a content point, non-reactivity and lack of lubricity appear locally in the layer, and this makes it easier for chipping to occur on the cutting edge, and also promotes wear progression, The interval was determined to be 0.005 to 0.1 μm.
The interval between the highest Al-Ti content point and the highest Cr-B content point is provided with an (Al, Ti) N deposition arc ion plating (AIP) device and a Cr-B deposition magnetron sputtering (SP) device. When forming a vapor deposition film by performing arc ion plating and sputtering at the same time using, for example, the rotation table can be adjusted by controlling the rotation speed of the rotation table mounted with the tool base. The composition change (Al, Ti, Cr, B) N in which the interval between the Al-Ti highest content point and the Cr-B highest content point becomes a desired value within the above numerical range by appropriately setting the rotation speed of Layers can be easily formed.

(D) Average layer thickness If the average layer thickness is less than 1 μm, the hard coating layer can ensure the desired high temperature hardness, high temperature strength, heat resistance, oxidation resistance, non-reactivity and lubricity over a long period of time. As a result, it is not possible to expect an improvement in wear resistance in high-speed cutting of a heat-resistant alloy. On the other hand, if the average layer thickness exceeds 8 μm, chipping tends to occur on the cutting edge. The average layer thickness was determined to be 1-8 μm.

  In the coated tool of the present invention, the composition change (Al, Ti, Cr, B) N layer constituting the hard coating layer as a whole has excellent high temperature hardness, high temperature strength, heat resistance, and oxidation resistance. Furthermore, since it also has excellent non-reactivity and lubricity, even when heat-resistant alloys such as Ti-base alloys, Ni-base alloys, and Co-base alloys are processed under high-speed cutting conditions with particularly large heat generation. It exhibits excellent wear resistance over a long period of time without causing welding or uneven wear.

  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. Of the arc ion plating apparatus on one side, and the cathode electrode (evaporation source) of the arc ion plating apparatus on one side, Al-Ti alloy having various component compositions, magnetron sputtering apparatus on the other side A CrB ₂ sintered body is mounted as a target (evaporation source), and a metal Ti for bombard cleaning is also mounted. Then, a DC bias voltage of −1000 V is applied to the tool base that rotates while rotating on the rotary table. Then, a current of 100 A is passed between the metal Ti of the cathode electrode and the anode electrode to generate an arc discharge, thereby cleaning the tool base surface with Ti bombardment,
(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 power of 3 kW is applied to the target of the CrB ₂ sintered body using a pulse power source to sputter CrB ₂ ,
(D) Al-Ti highest content points and Cr-B highest content points of the target compositions shown in Tables 3 and 4 are alternately formed on the surface of the tool base that rotates while rotating on the rotary table. , Repeatedly present at the target intervals shown in Table 4, and from the Al-Ti highest content point to the Cr-B highest content point, from the Cr-B highest content point to the Al-Ti highest content point, Al , Ti, Cr, B have a component concentration distribution structure in which the content ratio changes continuously, and the compositional change in target layer thickness (Al, Ti, Cr, B) N shown in Tables 3 and 4 is also shown. By depositing a hard coating layer composed of layers, the inventive coated tools 1 to 16 having a throwaway tip shape defined in ISO · CNMG120408 were produced.
In the above embodiment, the target interval between the highest Al-Ti content point and the highest Cr-B content point is determined by changing the rotational speed of the rotary table within a range of 0.5 to 10 rpm. It adjusted so that it might become a 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), Al-Ti-Cr-B alloys having various components are mounted, and metal Ti for bombard cleaning is also mounted. The inside of the apparatus is evacuated to a vacuum of 0.5 Pa or less. While being held, 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 passed between the metal Ti of the cathode electrode and the anode electrode. Arc discharge is generated, and the surface of the tool base is cleaned with Ti bombardment, and then nitrogen gas is introduced into the apparatus as a reaction gas to obtain a reaction atmosphere of 2 Pa. 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 each of the tool bases A1 to A10 and B1 to B6. By similarly depositing a hard coating layer composed of a compositionally uniform (Al, Ti, Cr, B) N layer having the target composition and the target layer thickness shown in Tables 5 and 6 on the surface, a slow-away tip is also formed. Shaped conventional coated tools 1-16 were produced respectively.

Next, in the state where each of the above-mentioned 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 conventional coated chips 1-16,
Work material: Round bar with four flutes at equal intervals in the longitudinal direction of an alloy having a composition of Ti-6% Al-4% V in mass%,
Cutting speed: 60 m / min. ,
Cutting depth: 1.0 mm,
Feed: 0.25 mm / rev. ,
Cutting time: 5 minutes,
In the following conditions (cutting conditions A), a dry high-speed intermittent cutting test of a Ti-based alloy (normal cutting speed is 30 m / min.),
Work material: Alloy having a composition of Ni-19% Cr-18.5% Fe-5.2% Cd-5% Ta-3% Mo-0.9% Ti-0.5% Al in mass% Round bar,
Cutting speed: 65 m / min. ,
Cutting depth: 1.2 mm,
Feed: 0.15 mm / rev. ,
Cutting time: 6 minutes,
Dry high-speed continuous cutting test of Ni-based alloy under the conditions (cutting condition B) (normal cutting speed is 40 m / min.),
Work material: 4 equal in the length direction of an alloy having a composition of Co-23% Cr-6% Mo-2% Ni-1% Fe-0.6% Si-0.4% C in mass%. Vertical grooved round bar,
Cutting speed: 55 m / min. ,
Cutting depth: 1.2 mm,
Feed: 0.2 mm / rev. ,
Cutting time: 5 minutes,
The dry high-speed intermittent cutting test (normal cutting speed is 30 m / min.) Of the Co-based alloy under the above conditions (cutting condition C), and measuring the flank wear width of the cutting edge in any cutting test did. 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 45 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. In the vapor deposition apparatus, under the same conditions as in Example 1 above, the Al-Ti highest content point and the Cr-B highest content point of the target composition shown in Table 9 along the layer thickness direction alternately. Repetitively present at the target intervals shown in Table 9, and from the Al-Ti highest content point to the Cr-B highest content point, from the Cr-B highest content point to the Al-Ti highest content point, Al, Ti A hard coating layer having a component concentration distribution structure in which the content ratios of Cr, B and B are continuously changed, and comprising a composition change (Al, Ti, Cr, B) N layer of the target layer thickness also shown in Table 9 Vapor deposition formation Accordingly, 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. Conventional coating end mills 1 to 8 as conventional coating tools were manufactured by vapor-depositing a hard coating layer composed of (Al, Ti, Cr, B) N layers.

Next, of the present invention coated end mills 1-8 and the conventional coated end mills 1-8,
About this invention coated end mills 1-3 and conventional coated end mills 1-3,
Work Material-Planar Dimensions: 100 mm × 250 mm, Thickness: 50 mm, Mass%, Co-20% Cr-15% W-10% Ni-1.5% Mn-1% Si-1% Fe-0 An alloy plate having a composition of 12% C;
Cutting speed: 45 m / min. ,
Groove depth (cut): 3.0 mm,
Table feed: 300 mm / min,
A dry high-speed grooving test of a Co-based alloy under the conditions (normal cutting speed is 25 m / min.),
About this invention coated end mills 4-6 and conventional coated end mills 4-6,
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 An alloy plate having a composition of% Al-0.7% Mn-0.4% Si,
Cutting speed: 50 m / min. ,
Groove depth (cut): 3.5 mm,
Table feed: 300 mm / min,
Ni-base alloy dry high-speed grooving test under the conditions (normal cutting speed is 30 m / min.),
For the coated end mills 7 and 8 of the present invention and the conventional coated end mills 7 and 8,
Workpiece material-planar dimensions: 100 mm × 250 mm, thickness: 50 mm, mass%, alloy plate material having a composition of Ti-3% Al-2.5% V,
Cutting speed: 45 m / min. ,
Groove depth (cut): 6.0 mm,
Table feed: 250 mm / min,
Dry high-speed grooving test of Ti-based alloy under the conditions (normal cutting speed is 20 m / min.)
In each groove cutting test, 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 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. The Al-Ti highest content point and the Cr-B highest content point of the target composition shown in Table 11 along the layer thickness direction under the same conditions as in Example 1 above were charged in a vapor deposition device equipped with a magnetron sputtering device. Are alternately present at the target intervals shown in Table 11, and from the Al-Ti highest content point to the Cr-B highest content point, from the Cr-B highest content point to the Al-Ti highest content point. The compositional change of the target layer thickness (Al, Ti, Cr, B) N, which has a component concentration distribution structure in which the content ratio of Al, Ti, Cr, B continuously changes and is also shown in Table 11 Layered hard By the covering layer vapor deposited, 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. Conventionally coated drills 1 to 8 as conventional coated tools were manufactured by vapor-depositing a hard coating layer composed of a compositionally uniform (Al, Ti, Cr, B) N layer.

Next, among the above-mentioned present invention coated drills 1-8 and conventional coated drills 1-8,
About this invention coated drill 1-3 and conventional coated drill 1-3,
Work Material-Planar Dimensions: 100 mm × 250 mm, Thickness: 50 mm, Mass%, Co-20% Cr-20% Ni-4% Mo-4% W-4% Cd-3% Fe-1.5 An alloy plate having a composition of% Mn-0.7% Si-0.38% C;
Cutting speed: 35 m / min. ,
Feed: 0.2 mm / rev,
Hole depth: 8 mm,
Wet high-speed drilling test of Co-based alloy under the conditions of (normal cutting speed is 20 m / min.),
About this invention coated drill 4-6 and conventional coated drills 4-6,
Workpiece material—planar dimensions: 100 mm × 250 mm, thickness: 50 mm, mass%, alloy plate material having a composition of Ti-6% Al-4% V,
Cutting speed: 45 m / min. ,
Feed: 0.15 mm / rev,
Hole depth: 15 mm,
A wet high-speed drilling test of a Ti-based alloy under the conditions (normal cutting speed is 25 m / min.),
About this invention covering drills 7 and 8 and conventional covering drills 7 and 8,
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 An alloy plate having a composition of% Ti-0.5% Al-0.3% Si-0.2% Mn-0.05% Cu-0.04% C,
Cutting speed: 50 m / min. ,
Feed: 0.25 mm / rev,
Hole depth: 20 mm,
Wet high-speed drilling test of Ni-based alloy under the conditions (normal cutting speed is 30 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 0.3 mm was measured. The measurement results are shown in Tables 11 and 12, respectively.

As a result, the composition changes (Al, Ti, Cr) constituting the hard coating layers of the present coated chips 1 to 16, the present coated end mills 1 to 8, and the present coated drills 1 to 8 as the present coated tool obtained as a result. B) The composition of the Al-Ti highest content point and the Cr-B highest content point of the N layer was measured by energy dispersive X-ray analysis using a transmission electron microscope. The composition was substantially the same as the content point and the highest content point of Cr-B. Further, compositionally uniform (Al, Ti, Cr, B) N constituting the hard coating layers of the conventional coated tips 1 to 16, the conventional coated end mills 1 to 8, and the conventional coated drills 1 to 8 as conventional coated tools. The composition of the layers was measured by energy dispersive X-ray analysis using a transmission electron microscope, and each 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 used for cutting under high-speed conditions accompanied by high heat generation of heat-resistant alloys such as Ti-base alloys, Ni-base alloys, and Co-base alloys. Even so, the composition change (Al, Ti, Cr, B) N layer constituting the hard coating layer as a whole has excellent high temperature hardness, high temperature strength, heat resistance, oxidation resistance, and excellent non-reaction. It has excellent heat resistance over a long period of time without the occurrence of welding and uneven wear, and the hard coating layer is uniform in composition (Al, Ti). , Cr, B) In conventional coated tools composed of N layers, high heat generation is involved in high-speed cutting, which causes welding and partial wear, which can lead to a service life in a relatively short time. it is obvious.

  As described above, the coated tool of the present invention is suitable for high-speed cutting of heat-resistant alloys such as Ti-base alloys, Ni-base alloys, and Co-base alloys with high heat generation, as well as cutting of general steel and ordinary cast iron. Even when it is used, it exhibits excellent wear resistance over a long period of time and exhibits excellent cutting performance. Therefore, FA of cutting equipment, labor saving and energy saving of cutting, and cost reduction It is possible to cope with the above sufficiently.

The vapor deposition apparatus which equipped the arc ion plating (AIP) apparatus and magnetron sputtering (SP) apparatus which were used in 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 a schematic explanatory drawing of the normal arc ion plating apparatus used in forming the hard coating layer which comprises a conventional coating tool.

Claims (1)

A rotary table of a vapor deposition apparatus in which a tungsten carbide-based cemented carbide or titanium carbonitride-based cermet is provided with an Al—Ti alloy as a cathode electrode on one side and a CrB ₂ sintered material as a target on the other side. While the tool base is rotated on a rotary table, Al and Ti are sputtered on the Al—Ti alloy cathode electrode side and sputtering on the CrB ₂ sintered material target side, and Al and In a surface-coated cutting tool in which a hard coating layer composed of a nitride layer of Ti, Cr and B is formed by vapor deposition,
(A) The hard coating layer has an average layer thickness of 1 to 8 μm, and the Al-Ti highest content point formed in the vicinity of the Al-Ti alloy cathode electrode along the thickness direction of the hard coating layer and the The Cr-B highest content point formed in the vicinity of the CrB ₂ sintered material target is alternately and repeatedly present at an interval of 0.005 to 0.1 μm,
(B) The content ratio of Al, Ti, Cr, B is continuous from the highest Al-Ti content point to the highest Cr-B content point and from the highest Cr-B content point to the highest Al-Ti content point. Has a component concentration distribution structure that changes periodically,
(C) The Al component, Ti component, Cr component, and B component at the Al-Ti highest content point formed in the vicinity of the Al-Ti alloy cathode electrode are X, When represented by Y, Q, and R, X is 0.40 to 0.60, Y is 0.30 to 0.50, Q is 0.01 to 0.10, and R is 0.01 to 0.10. And satisfies X + Y + Q + R = 1,
(D) The Al component, Ti component, Cr component, and B component at the highest Cr-B content point formed in the vicinity of the CrB ₂ sintered material target are X, When represented by Y, Q, and R, X is 0.05 to 0.20, Y is 0.05 to 0.20, Q is 0.25 to 0.40, and R is 0.40 to 0.55. And a composition change (Al, Ti, Cr, B) N layer satisfying X + Y + Q + R = 1 is formed by vapor deposition.
A surface-coated cutting tool that exhibits high wear resistance with a hard coating layer in high-speed cutting of heat-resistant alloys.

Images