JP2007038377A - Surface-coated cemented-carbide cutting tool with hard coating layer capable of showing excellent chipping resistance in high speed cutting of difficult-to-cut material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface-coated cemented-carbide cutting tool with a hard coating layer capable of showing excellent chipping resistance in high speed cutting of a difficult-to-cut material. <P>SOLUTION: The surface-coated cemented-carbide cutting tool has the hard coating layer on the surface of a base body composed of cemented carbide or cermet, the hard coating layer being composed of (a) a lower layer which has a mean layer thickness of 1 to 5 μm, and is composed of a (Ti, Al, Si)N layer in which a maximum Al containing point and a minimum Al containing point repeatedly exist, and the contents of Al and Ti continuously vary in the direction from the maximum Al containing point to the minimum Al containing point, and also in the reversed direction, respectively, and further the maximum Al containing points and the minimum Al containing points satisfy a specific composition formula, and the interval of adjacent maximum Al containing points and minimum Al containing points is 0.01 to 0.1 μm; (b) an interlayer adhesive layer composed of a vanadium nitride layer having a mean layer thickness of 0.1 to 1.5 μm; and (c) an upper layer which has a mean layer thickness of 1 to 5 μm, and has a texture in which a metal V is dispersively distributed in a matrix of VO<SB>M</SB>(vanadium oxide). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  This invention exhibits excellent chipping resistance with a hard coating layer, especially when cutting difficult-to-cut materials such as stainless steel, high manganese steel, and mild steel under high-speed cutting conditions with high heat generation. The present invention relates to a surface-coated cemented carbide cutting tool (hereinafter referred to as a coated cemented carbide tool).

  Generally, for coated carbide tools, a throw-away tip that is attached to the tip of a cutting tool for turning or flattening of various steel and cast iron work materials, and drilling of the work material. There are drills and miniature drills used for processing, etc., and solid type end mills used for chamfering, grooving, shoulder processing, etc. of the work material. A slow-away end mill tool that performs cutting work in the same manner as a type end mill is known.

Further, as a coated carbide tool, on the surface of a carbide substrate composed of tungsten carbide (hereinafter referred to as WC) -based cemented carbide or titanium carbonitride (hereinafter referred to as TiCN) -based cermet,
And having an average layer thickness of 1 to 15 μm, and along the layer thickness direction, Al highest content points and Al lowest content points are alternately present at predetermined intervals, and from the Al highest content point Al lowest content point, having a component concentration distribution structure in which the Al and Ti content continuously change from the Al lowest content point to the Al highest content point, respectively,
Furthermore, the Al highest content point, the composition _{formula: (Al 1- (X + Y} ) Ti X Si Y) N ( provided that an atomic ratio, X is 0.10 to 0.35, Y is from 0.01 to 0. 1)
The Al minimum content point is the composition formula: (Al _{1− (A + B)} Ti _A Si _B ) N (where A is 0.40 to 0.65 and B is 0.01 to 0.1 in atomic ratio). Show),
And an interval between the Al highest content point and the Al minimum content point adjacent to each other is 0.01 to 0.1 μm, a composite nitride layer of Al, Ti, and Si [hereinafter, composition change (Al, Ti, Si) N layer]
A coated carbide tool formed by physically vapor-depositing a hard coating layer is known, and the composition change (Al, Ti, Si) N layer, which is the hard coating layer of the coated carbide tool, changes the component concentration distribution. It has excellent high-temperature hardness and heat resistance due to the structure of Al, and excellent high-temperature strength due to the Ti, and combined with the further improvement of heat resistance due to the inclusion of the Si component, this can be used for various general steels and ordinary cast iron, etc. It is known that excellent cutting performance is exhibited not only when continuous cutting or intermittent cutting is used under normal conditions, but also when it is used under high-speed cutting conditions.

Further, the above conventional coated carbide tool has, for example, an arc ion plating apparatus having a structure shown in a schematic plan view in FIG. 2A and a schematic front view in FIG. A turntable for mounting is provided, and an Al—Ti—Si alloy having a relatively high Al content (low Ti content) on one side and a relatively high Ti content on the other side across the turntable. Using an arc ion plating apparatus in which an Al—Ti—Si alloy (with a low Al content) is disposed as a cathode electrode (evaporation source) and facing, a predetermined radial direction from the central axis of the apparatus is provided on the rotary table of the apparatus. A plurality of cemented carbide substrates are mounted in a ring shape at a distance from each other, and in this state, the atmosphere inside the apparatus is turned to a nitrogen atmosphere, the rotary table is rotated, and the thickness of the hard coating layer formed by vapor deposition is made uniform. For this purpose, while rotating the carbide substrate itself, an arc discharge is generated between the cathode electrode (evaporation source) and the anode electrode on both sides to change the composition on the surface of the carbide substrate (Al, Ti, Si) N layer is manufactured, and in the composition change (Al, Ti, Si) N layer formed as a result, the cemented carbide substrate arranged in a ring shape on the rotary table is the above-mentioned The highest Al content point is formed in the layer when it is closest to the cathode electrode (evaporation source) of the Al-Ti-Si alloy having a relatively high Al content (low Ti content) on one side of When the cemented carbide substrate is closest to the cathode electrode of the Al—Ti—Si alloy having a relatively high Ti content (low Al content) on the other side, a minimum Al content point is formed in the layer. By rotating the rotary table In the layer, the highest Al content point and the lowest Al content point appear alternately at predetermined intervals along the layer thickness direction, and the lowest Al content point from the highest Al content point, from the lowest Al content point, A component concentration distribution structure in which the Al and Ti contents continuously change to the Al highest content point is formed.
JP 2004-223619 A

  In recent years, FA has been remarkable for cutting devices, but on the other hand, there are strong demands for labor saving and energy saving and further cost reduction for cutting, and as a result, coated carbide tools have an influence on the grade of work material as much as possible. However, in the conventional coated carbide tools described above, this is a low alloy steel. There is no problem when used for high-speed cutting of general steel such as steel or carbon steel, or ordinary cast iron such as ductile cast iron or gray cast iron, but stainless steel with high chip viscosity and easy welding to the tool surface. When cutting difficult-to-cut materials such as steel, high-manganese steel, and mild steel at high speed, the work material and chips made of difficult-to-cut materials are heated to a high temperature due to high heat generated during cutting. Increased further. As a result, the adhesiveness and reactivity to the surface of the hard coating layer are further increased, and as a result, the occurrence of chipping (slight chipping) at the cutting edge portion increases rapidly, which causes a service life in a relatively short time. Is the current situation.

In view of the above, the present inventors have developed the above-mentioned conventional coating in order to develop a coated carbide tool that exhibits excellent chipping resistance with a hard coating layer, particularly in high-speed cutting of difficult-to-cut materials. As a result of conducting research with a focus on carbide tools,
(A) A composition change (Al, Ti, Si) N layer, which is a hard coating layer of the above conventional coated carbide tool, is formed with an average layer thickness of 1 to 5 μm as a lower layer, and vanadium oxide as an upper layer thereon (Hereinafter referred to as VO _M. However, M represents a change value of the relative content ratio of oxygen to vanadium (V), and represents VO, V ₂ O ₃ , V ₂ O ₅ , VO _{2 and the} like in atomic ratio. ) layer when similarly formed with an average layer thickness of 1 to 5 [mu] m, the VO _M layer is excellent surface slipperiness, this result workpiece by heat generated during cutting (difficult-to-cut materials) and its cutting scraps is high temperature heating Even in the state, excellent slipperiness is always ensured between the cutting edge (the rake face and the flank face, and the cutting edge ridge line where these two surfaces intersect) and the work material and the chip. The adhesiveness and reactivity to the cutting edge surface of the Since the composition change (Al, Ti, Si) N layer, which is the partial layer, is sufficiently protected, the excellent characteristics of the composition change (Al, Ti, Si) N layer can be sufficiently exhibited over a long period of time. To become.

(B) the the VO _M and matrix constituting the VO _M layer (a), which the VO _M and 0.5 to 7 atomic% of vanadium metal as a percentage of the total amount (hereinafter, indicated by metal V ) a dispersing contained, the metal V into a green body of VO _M is a V dispersed VO _M layer having dispersed distribution organization, in the V dispersed VO _M layer of this result, the metal V to disperse distribution into a green body, the cutting by oxidation with highly exothermic atmosphere with time, but the VO _M, since it acts to significantly suppress the wear progress of green bodies this product VO _M consists likewise VO _M, the VO _M layer of the (a) Be superior to wear resistance.
Further, V dispersed VO _M layer described above, for example, a metal V powder was heated oxidized in an oxidizing atmosphere and VO _M powder, this mixed a predetermined amount of the metal V powder, mixed and press-molded into a powder compact after, the green compact in an Ar atmosphere, and sintered under the conditions of 1 hour hold time at a temperature of 1300 ° C., to produce a V dispersion VO _M sintered body, the resulting V dispersed VO _M sintering The body can be formed by sputtering vapor deposition in an Ar atmosphere using the cathode electrode of the sputtering apparatus. ,

(C) On the other hand, the composition change is V dispersion VO _M layer and the lower layer is an upper layer (Al, Ti, Si) adhesion to the N layer is not sufficient, the interlayer especially when subjected to intermittent cutting of it adhesiveness insufficient chipping due likely to occur, the VO _M layer and the composition changes (Al, Ti, Si) between the N layer vanadium nitride (hereinafter indicated by VN) layer 0.1-1 When interposing an average layer thickness of .5Myuemu, the VN layer the VO _M layer and the composition changes (Al, Ti, Si) because it is also firmly adhered to one of the N layer, adhesion with excellent in both of these layers Will be secured.

(D) The hard coating layer constituted by the above (a) to (c) is, for example, an arc ion plating apparatus having a structure shown in a schematic plan view in FIG. 1 (a) and a schematic front view in (b). (Hereinafter abbreviated as AIP apparatus) and sputtering apparatus (hereinafter abbreviated as SP apparatus) coexisting vapor deposition apparatus, that is, a rotating table for mounting a carbide substrate is provided at the center of the apparatus, metal V as a cathode electrode of the AIP device side (evaporation source), a cathode electrode (vapor source) as V dispersion VO _M sintered body of the SP device on the other side opposed, further along the rotary table, and wherein (a low Ti content) while a relatively high Al content on the side of the position apart 90 ° from each of the metal V and V dispersed VO _M sintered Al-Ti-Si alloy, relative to the other side Ti-containing A vapor deposition apparatus in which an Al—Ti—Si alloy having a high amount (low Al content) was placed as a cathode electrode (evaporation source) opposed to each other was separated from the central axis on the rotary table of the apparatus by a predetermined distance in the radial direction. At the position, a plurality of carbide substrates are mounted in a ring shape along the outer periphery, and in this state, the rotary table is rotated with the atmosphere inside the apparatus as a nitrogen atmosphere, and the thickness of the hard coating layer formed by vapor deposition is made uniform. Basically, while rotating the carbide substrate itself for the purpose of aiming, first, arc discharge is generated between the cathode electrode (evaporation source) and the anode electrode of both the Al-Ti-Si alloys arranged opposite to each other, A composition change (Al, Ti, Si) N layer is deposited on the surface of the cemented carbide substrate as a lower layer with an average layer thickness of 1 to 5 μm, and then cathode electrodes (evaporation source) of both the Al—Ti—Si alloys. And The arc discharge between the cathode electrode and the anode electrode is stopped, and the arc in the apparatus is kept in the nitrogen atmosphere, and the arc discharge is generated between the metal V as the cathode electrode (evaporation source) and the anode electrode, After vapor-depositing the VN layer as an interlayer adhesion layer with an average layer thickness of 0.1 to 1.5 μm, the arc discharge between the metal V and the anode electrode is stopped, and the atmosphere in the vapor deposition apparatus is set to an Ar atmosphere. with the cathode electrode V dispersed VO _M layer with an average layer thickness of 1~5μm as an upper layer overlapping the VN layer disposed was performed sputtering of V dispersion VO _M sintered body as (evaporation source) of the SP device It can be formed by vapor deposition.

(D) The coated carbide tool formed by vapor-depositing the hard coating layer composed of the lower layer, the interlayer adhesion layer, and the upper layer is a stainless steel, a high manganese steel, and a mild steel that are particularly highly viscous and sticky. Even in high-speed cutting with high heat generation such as difficult-to-cut materials, the lower layer composition change (Al, Ti, Si) N layer has excellent high temperature hardness and heat resistance, and excellent high temperature strength, the heat resistance becomes that further improved by coexistence content of the Si component, and the V dispersion VO _M layer excellent adhesion bonding property between the lower layer by an intervening the VN layer is ensured as an interlayer adhesion layer With this action, excellent slipperiness between the difficult-to-cut material and the chips is ensured, and the sticking and reactivity of the difficult-to-cut material and chips to the surface of the cutting edge are significantly reduced. Is going to be done In addition, chipping will not occur at the cutting edge, and excellent wear resistance will be exhibited over a long period of time.
The research results shown in (a) to (d) above were obtained.

This invention was made based on the above research results, and on the surface of the carbide substrate,
(A) It has an average layer thickness of 1 to 5 μm, and along the layer thickness direction, Al maximum content points and Al minimum content points are alternately present at predetermined intervals, and the Al maximum content A component concentration distribution structure in which the Al and Ti contents continuously change from the point to the Al minimum content point, from the Al minimum content point to the Al maximum content point,
Furthermore, the Al highest content point, the composition _{formula: (Al 1- (X + Y} ) Ti X Si Y) N ( provided that an atomic ratio, X is 0.10 to 0.35, Y is from 0.01 to 0. 1)
The Al minimum content point is the composition formula: (Al _{1− (A + B)} Ti _A Si _B ) N (where A is 0.40 to 0.65 and B is 0.01 to 0.1 in atomic ratio). Show),
And a lower layer composed of a composition change (Al, Ti, Si) N layer in which the interval between the Al highest content point and the Al lowest content point adjacent to each other is 0.01 to 0.1 μm,
(B) an interlayer adhesion layer comprising a VN layer having an average layer thickness of 0.1 to 1.5 μm;
(C) it has an average layer thickness of 1 to 5 [mu] m, and the matrix of VO _M, a percentage of the total amount of the VO _M, with a tissue 0.5 to 7 atomic% of the metal V are dispersed distribution An upper layer consisting of V-dispersed VO _M layers;
What is characterized by a coated carbide tool that exhibits a chipping resistance with excellent hard coating layer in high-speed cutting of difficult-to-cut materials, formed by forming a hard coating layer composed of (a) to (c) above It is.

Next, the reason why the numerical values of the constituent layers of the hard coating layer of the coated carbide tool of the present invention are limited as described above will be described.
(A) Lower layer (a) Composition of Al highest content point Al component of composition change (Al, Ti, Si) N layer improves high temperature hardness and heat resistance, the Ti component improves high temperature strength, Furthermore, the Si component has the effect of further improving the heat resistance, and therefore, at the highest Al content point where the content ratio of the Al component is relatively high, it has excellent high-temperature hardness and heat resistance, and is capable of high-speed cutting with high heat generation. However, when the X value indicating the ratio of Ti occupies the total amount of Al and Si (atomic ratio) is less than 0.10, the ratio of Al is relatively high. Even if there is an Al minimum content point having a relatively high high-temperature strength adjacent to each other, a decrease in the strength of the layer itself is inevitable, and as a result, chipping and the like are likely to occur, while the proportion of the Ti component X value of Then, the proportion of Al becomes relatively small, and it becomes impossible to secure desired excellent high-temperature hardness and heat resistance, and the Y value indicating the proportion of Si component is the total amount of Al and Ti. If the proportion (atomic ratio) is less than 0.01, the desired heat resistance improvement effect cannot be obtained, and if the Y value exceeds 0.10, the high-temperature strength suddenly decreases. Was set to 0.10 to 0.35, and the Y value was set to 0.01 to 0.10.

(B) Composition of Al minimum content point As described above, the Al maximum content point is excellent in high-temperature hardness and heat resistance, but on the other hand, it is inferior in high-temperature strength. In order to compensate for this, the Ti content ratio is relatively high, thereby interposing the Al minimum content points that have high high-temperature strength alternately in the thickness direction, and therefore the Ti ratio (A value) is If the ratio (atomic ratio) in the total amount of Al and Si is less than 0.40, the desired excellent high-temperature strength cannot be ensured, while the ratio (A value) also exceeds 0.65. The ratio of Ti is set to 0.40 to 0.65 because the ratio of Ti becomes relatively large and the Al minimum content point cannot be provided with the predetermined high temperature hardness and heat resistance. And the Si component The B value indicating the ratio was determined to be 0.01 to 0.10 for the same reason as in the above Al highest content point.

(C) Interval between the highest Al content point and the lowest Al content point If the distance is less than 0.01 μm, it is difficult to clearly form each point with the above composition. As a result, each layer has a desired high temperature. Hardness, heat resistance, and high-temperature strength cannot be ensured, and if the distance exceeds 0.1 μm, each point has a defect, that is, if Al is the highest content point, insufficient high-temperature strength, Al minimum content point If so, high-temperature hardness and insufficient heat resistance appear locally in the layer, which makes it easier for chipping to occur on the cutting edge and promotes the progress of wear. It was defined as ˜0.1 μm.

(D) Average layer thickness If the average layer thickness is less than 1 μm, the desired wear resistance cannot be ensured. On the other hand, if the average layer thickness exceeds 5 μm, chipping tends to occur on the cutting edge. The average layer thickness was determined to be 1 to 5 μm.

(B) Average layer thickness of interlayer adhesion layer If the average layer thickness is less than 0.1 μm, it is not possible to ensure a strong bonding strength between the upper layer and the lower layer, while the average layer thickness is 1.5 μm. If it exceeds 1, the strength of the hard coating layer suddenly decreases in the interlayer adhesion layer portion, which causes the occurrence of chipping. Therefore, the average layer thickness was determined to be 0.1 to 1.5 μm.

(C) V dispersion VO _M layer constituting the content upper layer of the average layer thickness and dispersed metal V of the upper layer is excellent has a surface slip properties, as described above workpiece (difficult-to-cut materials) and switching The adhesiveness and reactivity to powder are extremely low, and this is maintained without changing even when the work material is heated at the time of cutting, so the composition change (Al, Ti, Si) N layer as the lower layer Is protected from the high-temperature heated work material and chips, and the effect of suppressing the occurrence of chipping is exerted. However, if the average layer thickness is less than 1 μm, the desired effect cannot be obtained in the above-described operation. If the average layer thickness exceeds 5 μm and becomes too thick, chipping is likely to occur. Therefore, the average layer thickness was set to 1 to 5 μm.
Further, the metal V in V dispersed VO _M layer above, by oxidation with a high heating atmosphere during cutting as described above, next VO _M, the wear progress of green bodies produced VO _M of this result consists likewise VO _M There is remarkable inhibitory action, therefore, the V distributed VO _M layer, show compared to VO _M layer consisting only VO _M excellent wear resistance for constituting the matrix, the content of the metal V, matrix a percentage of the total amount of the VO _M layer is less than 0.5 atomic% can not be obtained the desired wear resistance improving effect, whereas the content of the metal V exceeds the same 7 atomic%, the layer itself Since the strength is abruptly reduced and causes chipping, the content is determined to be 0.5 to 7 atomic%.

In the coated carbide tool of this invention, the composition change (Al, Ti, Si) N layer of the lower layer constituting the hard coating layer has excellent high temperature hardness and heat resistance, and excellent high temperature strength. the V dispersion VO _M layer as an upper layer was firmly adhered joined by VN layer as an interlayer adhesion layer, since the superior surface slipperiness between the workpiece (difficult-to-cut materials) and chips is ensured In particular, it shows excellent chipping resistance and high wear resistance over a long period of time even in high-speed cutting with high heat generation of difficult-to-cut materials such as highly viscous and sticky stainless steel, high manganese steel, and mild steel It demonstrates the nature.

  Next, the coated carbide 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 carbide substrates A-1 to A-10 were formed.

Further, 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 / Carbide substrates B-1 to B-6 made of TiCN-based cermet having a chip shape of CNMG120408 were formed.

Furthermore, as a cathode electrode (evaporation source) for forming the upper layer of the hard coating layer, first, a metal V powder having an average particle diameter of 0.8 μm is prepared, and this is placed in an oxidizing atmosphere of 10 Pa at a temperature of 1000 ° C. for 1 hour. by heating oxidation treatment under conditions of retention, and VO _M powder, likewise an average particle diameter thereto: a 0.8μm of metal V powder predetermined amount, after 72 hours wet mixed in a ball mill and dried, the pressure of 100MPa Is pressed into a green compact, and the green compact is sintered in a 6 Pa Ar atmosphere at a predetermined temperature within a range of 1200 to 1400 ° C. for 1 hour, thereby allowing the metal V to be predetermined. V dispersion VO _M sintered body containing dispersed at a ratio was prepared.

(A) Next, each of the above-mentioned carbide substrates A-1 to A-10 and B-1 to B-6 was ultrasonically cleaned in acetone and dried, and then in the vapor deposition apparatus shown in FIG. Attached along the outer peripheral portion at a predetermined distance in the radial direction from the central axis on the rotary table, an interlayer adhesion layer forming metal V as the cathode electrode (evaporation source) of the AIP device on one side, and the SP on the other side the upper layer forming V dispersion VO _M sintered body placed opposite a cathode (evaporation source) of the device, further along said rotating table, and each 90 degrees of the metal V and V dispersed VO _M sintered body An Al—Ti—Si alloy for forming the highest Al content point of the lower layer as the cathode electrode (evaporation source) on one side of the remote position, and an Al—Ti—Si alloy for forming the lowest Al content point of the lower layer on the other side as well. Facing each other,
(B) First, the inside of the apparatus is evacuated and kept at a vacuum of 0.1 Pa or less, and the inside of the apparatus is heated to 500 ° C. with a heater, and then the carbide substrate that rotates while rotating on the rotary table is set to −1000 V. And a 100 A current is passed between one of the two Al-Ti-Si alloys for forming the lower layer of the cathode electrode and the anode electrode to generate an arc discharge. The carbide substrate surface is bombarded with the Al-Ti-Si alloy,
(C) Next, nitrogen gas is introduced as a reaction gas into the apparatus to form a reaction atmosphere of 4 Pa, and a DC bias voltage of −100 V is applied to a carbide substrate that rotates while rotating on the rotary table, An arc discharge is generated by flowing a current of 100 A between each cathode electrode (the Al-Ti-Si alloy for forming the highest Al content point and the Al-Ti-Si alloy for forming the lowest Al content point) and the anode electrode. Thus, on the surface of the carbide substrate, the Al highest content point and the Al lowest content point of the target composition shown in Tables 3 and 4 along the layer thickness direction alternately at the target intervals shown in Tables 3 and 4 as well. It has a component concentration distribution structure that repeatedly exists and the Al (Ti) content continuously changes from the Al highest content point to the Al lowest content point, from the Al lowest content point to the Al highest content point, One also change in composition with a target layer thickness shown in Table 3,4 (Al, Ti, Si) N layer were vapor deposited as the lower layer of the hard coating layer,
(D) The arc discharge between the cathode electrode and the anode electrode of both the Al-Ti-Si alloys for forming the lower layer is stopped, the atmosphere in the apparatus is kept in a nitrogen atmosphere of 4 Pa, and the carbide substrate Under the condition that the direct current bias voltage to -100V is also -100V, an arc discharge is generated by passing a current of 120A between the metal V of the cathode electrode and the anode electrode. A thick VN layer is deposited as an interlayer adhesion layer of a hard coating layer,
(E) Arc discharge between the metal V and the anode electrode is stopped, the atmosphere in the vapor deposition apparatus is changed to an Ar atmosphere of 0.5 Pa, and a V-dispersed VO arranged as a cathode electrode (evaporation source) of the SP apparatus Sputtering was started on the _M sintered body under the condition of sputtering output: 3 kW, V having the target layer thickness shown in Tables 3 and 4 and containing metal V corresponding to the metal V target content ratio in a dispersed manner. by depositing form a dispersion VO _M layer as the upper layer of the hard coating layer, the present invention coated carbide tool as the present invention the surface coating cemented carbide indexable (hereinafter, referred to as the present invention coated chip) 1 to 16 Each was manufactured.

For comparison purposes,
(A) Each of the above-mentioned carbide substrates A1 to A10 and B1 to B6 is ultrasonically cleaned in acetone and dried, and the outer peripheral portion is placed on the rotary table in the arc ion plating apparatus shown in FIG. As a cathode electrode (evaporation source) on one side, an Al-Ti-Si alloy for forming the lowest Al content point having various component compositions, and various cathode electrodes (evaporation source) on the other side Al-Ti-Si alloy for forming the highest Al content point having a component composition is disposed oppositely across the rotary table,
(B) First, the inside of the apparatus was heated to 500 ° C. with a heater while the inside of the apparatus was evacuated and kept at a vacuum of 0.1 Pa or less, and then a DC bias voltage of −1000 V was applied to the cemented carbide substrate, and An arc discharge is generated by flowing a current of 100 A between either one of the two Al—Ti—Si alloys of the cathode electrode and the anode electrode, so that the surface of the carbide substrate is made of the Al—Ti—Si alloy. Bombard washed,
(C) Next, nitrogen gas is introduced as a reaction gas into the apparatus to form a reaction atmosphere of 4 Pa, and a DC bias voltage of −100 V is applied to a carbide substrate that rotates while rotating on the rotary table, An arc discharge is generated by flowing a current of 100 A between each cathode electrode (the Al-Ti-Si alloy for forming the lowest Al content point and the Al-Ti-Si alloy for forming the highest Al content point) and the anode electrode. Thus, on the surface of the cemented carbide substrate, the Al minimum content point and the Al maximum content point of the target composition shown in Tables 5 and 6 along the layer thickness direction alternately at the target intervals shown in Tables 5 and 6 as well. It has a component concentration distribution structure that repeatedly exists and the Al (Ti) content continuously changes from the Al highest content point to the Al lowest content point, from the Al lowest content point to the Al highest content point, Similarly, a conventional coated carbide tool is formed by depositing a composition change (Al, Ti, Si) N layer corresponding to the lower layer of the above-described coated chip of the present invention having the target layer thickness shown in Tables 5 and 6 as a hard coating layer. Conventional surface-coated cemented carbide throwaway tips (hereinafter referred to as conventional coated tips) 1 to 16 were produced respectively.

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 to 16 and the conventional coated chips 1 to 16 are as follows.
Work material: JIS / S15C round bar,
Cutting speed: 380 m / min. ,
Incision: 1.5mm,
Feed: 0.25 mm / rev. ,
Cutting time: 10 minutes,
Dry continuous high-speed cutting test of mild steel under the conditions (cutting condition A) (normal cutting speed is 250 m / min.),
Work material: JIS / SUS316 lengthwise equidistant 4 round grooved round bars,
Cutting speed: 350 m / min. ,
Cutting depth: 1.2mm,
Feed: 0.3 mm / rev. ,
Cutting time: 5 minutes
A dry intermittent high-speed cutting test of stainless steel under the conditions (cutting condition B) (normal cutting speed is 200 m / min.),
Work material: JIS · SCMnH1 lengthwise equidistant four round grooved round bars,
Cutting speed: 320 m / min. ,
Incision: 1.5mm,
Feed: 0.3 mm / rev. ,
Cutting time: 5 minutes
Of high manganese steel under normal conditions (cutting condition C) (normal cutting speed was 200 m / min.), 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 3 types of sintered carbide rod-forming bodies for forming a carbide substrate having diameters of 8 mm, 13 mm, and 26 mm were formed, and further, the three types of sintered rods for round bar were subjected to grinding, as shown in Table 7. Made of WC-base cemented carbide with a combination of 4 blade square shape with diameter and length of 6mm × 13mm, 10mm × 22mm, and 20mm × 45mm respectively, and a twist angle of 30 degrees. Carbide substrates (end mills) C-1 to C-8 were produced.

Subsequently, the surfaces of these carbide substrates (end mills) C-1 to C-8 were ultrasonically cleaned in acetone and dried, and then charged into the vapor deposition apparatus shown in FIG. And the Al minimum content point and the Al maximum content point of the target composition shown in Table 9 along the layer thickness direction alternately and repeatedly exist at the target interval shown in Table 9, and the Al maximum A target layer having a component concentration distribution structure in which the Al (Ti) content continuously changes from the content point to the Al minimum content point, from the Al minimum content point to the Al maximum content point, and also shown in Table 9 Composition change in thickness (Al, Ti, Si) A lower layer composed of an N layer, an interlayer adhesion layer composed of a VN layer having the target layer thickness shown in Table 9, and a target layer thickness also shown in Table 9. And metal V corresponding to the target content ratio of metal V By depositing form a hard coating layer composed of a top layer made of V dispersed VO _M layer dispersed containing Re respectively, the present invention present invention surface coating cemented carbide end mills of the coated cemented carbide (hereinafter, the present invention 1 to 8 were produced.

  For the purpose of comparison, the surfaces of the above-mentioned carbide substrates (end mills) C-1 to C-8 are ultrasonically cleaned in acetone and dried, and the arc ion plating apparatus shown in FIG. In the same condition as in Example 1 above, the lowest Al content point and the highest Al content point of the target composition shown in Table 10 along the layer thickness direction are alternately at the target interval shown in Table 10 It has a component concentration distribution structure that repeatedly exists and the Al (Ti) content continuously changes from the Al highest content point to the Al lowest content point, from the Al lowest content point to the Al highest content point, and Similarly, a conventional change as a conventional coated carbide tool is performed by depositing a composition change (Al, Ti, Si) N layer corresponding to the lower layer of the above-described coated end mill of the present invention having a target layer thickness shown in Table 10 as a hard coating layer. Surface coated carbide End mill (hereinafter, conventional coating end mill called) was 1-8 were prepared, respectively.

Next, of the present invention coated end mills 1-8 and conventional coated end mills 1-8, the present invention coated end mills 1-3 and conventional coated end mills 1-3 are as follows:
Work material-Plane dimensions: 100 mm x 250 mm, thickness: 50 mm JIS / SUS316 plate material,
Cutting speed: 110 m / min. ,
Groove depth (cut): 3 mm,
Table feed: 160 mm / min,
For the stainless steel dry high-speed grooving test (normal cutting speed is 70 m / min.), The coated end mills 4 to 6 and the conventional coated end mills 4 to 6
Work material-planar dimensions: 100 mm x 250 mm, thickness: 50 mm JIS / S15C plate,
Cutting speed: 90 m / min. ,
Groove depth (cut): 5 mm,
Table feed: 180mm / min,
With respect to the dry high-speed grooving test of mild steel under the conditions (normal cutting speed is 60 m / min.), The present coated end mills 7 and 8 and the conventional coated end mills 7 and 8,
Work material-planar dimensions: 100 mm × 250 mm, thickness: 50 mm JIS / SCMnH1 plate material,
Cutting speed: 80 m / min. ,
Groove depth (cut): 10 mm,
Table feed: 160 mm / min,
Each of the high-manganese steel dry high-speed grooving test (normal cutting speed is 50 m / min.) Under the above conditions. The flank wear width of the outer peripheral edge of the cutting edge is the service life in any grooving test. The cutting groove length up to 0.1 mm, which is a guideline, was measured. The measurement results are shown in Tables 9 and 10, respectively.

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

Next, the cutting edges of these carbide substrates (drills) D-1 to D-8 are subjected to honing, ultrasonically cleaned in acetone, and dried, and then loaded into the vapor deposition apparatus shown in FIG. Then, under the same conditions as in Example 1, the lowest Al content point and the highest Al content point of the target composition shown in Table 11 along the layer thickness direction are repeatedly present at the target intervals shown in Table 11 alternately. And a component concentration distribution structure in which the Al (Ti) content continuously changes from the Al highest content point to the Al lowest content point, from the Al lowest content point to the Al highest content point, and The target layer thickness composition change (Al, Ti, Si) N layer shown in FIG. 11, the interlayer adhesion layer consisting of the VN layer of the target layer thickness also shown in Table 11, and also shown in Table 11 Target layer thickness and metal V target By depositing form a hard coating layer composed of a top layer made of a metal V corresponding to chromatic ratio from V dispersed VO _M layer dispersed containing respectively present invention surface coating made of cemented carbide as the present invention coated cemented carbide Drills (hereinafter referred to as the present invention-coated drills) 1 to 8 were produced.

  For comparison purposes, the surfaces of the above-mentioned carbide substrates (drills) D-1 to D-8 are honed, ultrasonically cleaned in acetone, and dried, and the arc shown in FIG. In an ion plating apparatus, under the same conditions as in Example 1, the Al minimum content point and the Al maximum content point of the target composition shown in Table 12 along the layer thickness direction are alternately shown in Table 12 A component concentration distribution structure in which the Al (Ti) content continuously exists from the Al highest content point to the Al lowest content point, and the Al (Ti) content continuously changes from the Al lowest content point to the Al highest content point. And a composition change (Al, Ti, Si) N layer corresponding to the lower layer of the above-described coated drill of the present invention having the target layer thickness shown in Table 12 is formed by vapor deposition as a hard coating layer. As a carbide tool Come surface coating cemented carbide drills (hereinafter, conventional coating drill called) was 1-8 were prepared, respectively.

Next, of the present invention coated drills 1 to 8 and the conventional coated drills 1 to 8, the present invention coated drills 1 to 3 and the conventional coated drills 1 to 3 are:
Work material-planar dimensions: 100 mm x 250 mm, thickness: 50 mm JIS / S15C plate,
Cutting speed: 160 m / min. ,
Feed: 0.25mm / rev,
Hole depth: 8mm,
About the wet high speed drilling cutting test (normal cutting speed is 100 m / min.) Of the mild steel under the conditions of the present invention, the coated drills 4 to 6 and the conventional coated drills 4 to 6
Work material-planar dimensions: 100 mm × 250 mm, thickness: 50 mm JIS / SCMnH1 plate material,
Cutting speed: 150 m / min. ,
Feed: 0.25mm / rev,
Hole depth: 16mm,
For the high-manganese steel wet high speed drilling test under the conditions (normal cutting speed is 90 m / min.), The present invention coated drills 7 and 8 and the conventional coated drills 7 and 8,
Work material-Plane dimensions: 100 mm x 250 mm, thickness: 50 mm JIS / SUS316 plate material,
Cutting speed: 120 m / min. ,
Feed: 0.3mm / rev,
Hole depth: 28mm,
Each of the high-speed wet drilling test (normal cutting speed is 80 m / min.) Of stainless steel under the above conditions is performed, and any wet high-speed drilling test (using water-soluble cutting oil) The number of drilling processes until the flank wear width reached 0.3 mm was measured. The measurement results are shown in Tables 11 and 12, respectively.

As a result, the coated chips 1 to 16 of the present invention as the coated carbide tool of the present invention, the hard coated layers of the coated end mills 1 to 8 and the coated drills 1 to 8 of the present invention, and the conventional coated carbide tool Al minimum content point and Al maximum content point of composition change (Al, Ti, Si) N layer constituting hard coating layer of conventional coated chips 1-16, conventional coated end mills 1-8, and conventional coated drills 1-8, respectively. When the composition was measured by energy dispersive X-ray analysis using a transmission electron microscope, the composition showed substantially the same composition as the lowest Al content and the highest Al content of the target composition.
Moreover, as measured by the present invention V dispersed VO _M layer constituting the hard coating layer of the coated cemented carbide tools energy dispersive X-ray analysis of the composition of (upper layer) likewise with a transmission electron microscope, dispersed in the matrix metal V represents substantially the same content as the target content to be further matrix of VO _M is a composition formula, as a main component VO, this _{V 2 O 3, V 2 O} 5, and VO _2, etc. Shows the mixed structure contained.

  Further, when the average layer thickness of the constituent layers of the hard coating layer was subjected to cross-sectional measurement using a scanning electron microscope, all showed the same average value (average value of five locations) as the target layer thickness.

From the results shown in Tables 3 to 12, all of the coated carbide tools of the present invention are particularly high-speed cutting accompanied by high heat generation of difficult-to-cut materials such as highly viscous and sticky stainless steel, high manganese steel, and mild steel. Even in processing, the composition change (Al, Ti, Si) N layer, which is the lower layer of the hard coating layer, has excellent high-temperature hardness and heat resistance, excellent high-temperature strength, and the VN layer as an interlayer adhesion layer. the V dispersion VO _M layer firmly adhered to the lower layer, wherein since the superior surface slipperiness between the workpiece and chips is ensured, without the occurrence of chipping in the cutting edge, over a long period In the conventional coated carbide tool in which the hard coating layer is composed of a composition change (Al, Ti, Si) N layer, while exhibiting excellent wear resistance, all of the above difficult-to-cut materials are cut at high speed. In machining, work material (hard-to-cut material) and cutting It is clear that the adhesiveness and reactivity between the powder and the hard coating layer are further increased, and this causes chipping at the cutting edge, leading to a service life in a relatively short time.

  As described above, the coated carbide tool of the present invention has excellent chipping resistance not only in cutting of general steel and ordinary cast iron, but also in high-speed cutting with high heat generation of the above difficult-to-cut materials. Since the cutting performance is excellent and exhibits excellent cutting performance over a long period of time, it is possible to satisfactorily respond to the FA of the cutting device, the labor saving and energy saving of the cutting work, and the cost reduction.

The vapor deposition apparatus used in forming the hard coating layer which comprises this invention coated carbide tool is shown, (a) is a schematic plan view, (b) is a schematic front view. The arc ion plating apparatus used for forming the hard coating layer which comprises a conventional coated carbide tool is shown, (a) is a schematic plan view, (b) is a schematic front view.

Claims (1)

On the surface of the cemented carbide substrate composed of tungsten carbide based cemented carbide or titanium carbonitride based cermet,
(A) It has an average layer thickness of 1 to 5 μm, and along the layer thickness direction, Al maximum content points and Al minimum content points are alternately present at predetermined intervals, and the Al maximum content A component concentration distribution structure in which the Al and Ti contents continuously change from the point to the Al minimum content point, from the Al minimum content point to the Al maximum content point,
Furthermore, the Al highest content point, the composition _{formula: (Al 1- (X + Y} ) Ti X Si Y) N ( provided that an atomic ratio, X is 0.10 to 0.35, Y is from 0.01 to 0. 1)
The Al minimum content point is the composition formula: (Al _{1− (A + B)} Ti _A Si _B ) N (where A is 0.40 to 0.65 and B is 0.01 to 0.1 in atomic ratio). Show),
A lower layer composed of a composite nitride layer of Al, Ti, and Si, wherein the distance between the Al highest content point and the Al lowest content point adjacent to each other is 0.01 to 0.1 μm,
(B) an interlayer adhesion layer comprising a vanadium nitride layer having an average layer thickness of 0.1 to 1.5 μm;
(C) having an average layer thickness of 1 to 5 μm, and having a structure in which 0.5 to 7 atomic% of metal vanadium is dispersed and distributed in the vanadium oxide base in a proportion of the total amount with the vanadium oxide. An upper layer comprising a metal vanadium dispersed vanadium oxide layer,
A surface-coated cemented carbide cutting tool that exhibits excellent chipping resistance in high-speed cutting of difficult-to-cut materials, which is formed by forming the hard coating layer configured as described above in (a) to (c).

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