JP2007030098A - Cutting tool made of surface coated cemented carbide having hard coarted layer exhibiting excellent chipping resistance in high-speed cutting material hard to cut - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cutting tool made of surface coated cemented carbide having a hard coarted layer exhibiting excellent chipping resistance in cutting a material hard to cut. <P>SOLUTION: In the cutting tool made of surface coated cemented carbide, a hard coated layer formed of following layers (a) to (c) is formed on the surface of a tungsten carbide-base body or a titanium carbide nitride-base cermet base body: (a) a lower layer formed of (Ti, Al, Si)N layer having an average layer thickness ranging from 1 to 5 μm, and having a component concentration distribution structure in which Al maximum content points (hereinafter referred to as A point) and Al minimum content points (hereinafter referred to as B point) alternately repeatedly exist at predetermined intervals along the direction of layer thickness, the Al content and Ti content respectively continuously vary from the A point to the B point, the A point satisfies a specified composition formula (Al<SB>1-(X+Y</SB>)Ti<SB>X</SB>Si<SB>Y</SB>)N, theB point satisfies a specified composition formula(Al<SB>1-(A+B)</SB>Ti<SB>A</SB>Si<SB>B</SB>)N, and the interval between the adjacent A point and the B point is 0.01 to 0.1 μm; (b) an inter-layer contact layer formed of a vanadium nitride layer; and (c) an upper layer formed of a vanadium oxide layer. <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 referred to as (Al, Ti, Si) N] layer,
A coated carbide tool formed by physically vapor-depositing a hard coating layer made of the above is known, and the (Al, Ti, Si) N layer, which is a hard coating layer of the coated carbide tool, has a component concentration distribution change structure. Combined with the high-temperature hardness and heat resistance superior by Al, the high-temperature strength superior by the Ti, and further improved heat resistance due to the inclusion of Si components, this can be used for continuous cutting of various general steels and ordinary cast iron, etc. It is also known that excellent cutting performance is exhibited not only when used to perform intermittent cutting under normal conditions, but also when used for 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, arc discharge is generated between the cathode electrode (evaporation source) and the anode electrode on both sides while rotating the carbide substrate itself for the purpose of (Al, Ti, Si) on the surface of the carbide substrate. In the (Al, Ti, Si) N layer formed as a result, the cemented carbide substrate arranged in a ring shape on the rotary table is formed on the one side. When the Al-Ti-Si alloy cathode electrode (evaporation source) of the Al-Ti-Si alloy having a relatively high Al content (low Ti content) is closest, the highest Al content point is formed in the layer. At the point 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, and the rotary table Layer thickness in the layer by rotating The Al highest content point and the Al lowest content point alternately appear at predetermined intervals along the direction, the Al highest content point to the Al lowest content point, the Al lowest content point to the Al highest content point, Al and A component concentration distribution structure in which the Ti content continuously changes 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.

Therefore, the present inventors, from the viewpoint as described above, particularly in cutting of difficult-to-cut materials,
In order to develop a coated carbide tool that exhibits excellent chipping resistance with a hard coating layer, as a result of research conducted focusing on the above conventional coated carbide tool,
(A) The (Al, Ti, Si) N layer, which is a hard coating layer of the above-mentioned conventional coated carbide tool, is formed with an average layer thickness of 1 to 5 μm as a lower layer, and vanadium oxide (hereinafter referred to as an upper layer) thereon. , VO _M, where _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, etc. in terms of atomic ratio) When the same is formed with an average layer thickness of 1 to 5 [mu] m, the VO _M layer is excellent surface slipperiness, even when this result workpiece by heat generated during cutting (difficult-to-cut materials) and its cutting scraps is high temperature heating 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 chips. The adhesiveness and reactivity to the blade surface are significantly reduced. That (Al, Ti, Si) N-layer because it sufficiently protect, (Al, Ti, Si) having excellent characteristics N layer may become to be sufficiently exhibited for a long time.

(B) On the other hand, a VO _M layer and the lower layer is an upper layer (Al, Ti, Si) adhesion to the N layer is not sufficient, the lack adhesion between the layers of especially when subjected to intermittent cutting There is easy chipping caused by the VO _M layer and (Al, Ti, Si) vanadium nitride between the N layer (hereinafter, indicated by VN) layer average thickness of 0.1~1.5μm the in the interposing, the VN layer the VO _M layer and (Al, Ti, Si) from that than either strongly adhered of N layers, it comes to be ensured good adhesion to both of these layers .

(C) The hard coating layer constituted by the above (a) and (b) is, for example, an arc ion plating apparatus having a structure shown in FIG. 1 (a) in a schematic plan view and in FIG. That is, a rotating table for mounting a cemented carbide substrate is provided in the center of the apparatus, and an Al—Ti—Si alloy having a relatively high Al content (low Ti content) is placed on one side across the turntable, and the other side. The Al—Ti—Si alloy having a relatively high Ti content (low Al content) was placed opposite to each other as a cathode electrode (evaporation source), and was further 90 degrees away from each of the two Al—Ti—Si alloys. An arc ion plating apparatus in which metal V (vanadium) is arranged as a cathode electrode (evaporation source) at a position is provided along the outer periphery at a position that is a predetermined distance in the radial direction from the central axis on the rotary table of the apparatus. A number of carbide substrates are mounted in a ring shape, and in this state, the atmosphere inside the apparatus is changed to a nitrogen atmosphere to rotate the rotary table, and the carbide substrate itself is used for the purpose of uniformizing the thickness of the hard coating layer formed by vapor deposition. Basically, arc discharge is first generated between the cathode electrode (evaporation source) and the anode electrode of the two Al—Ti—Si alloys arranged opposite to each other on the surface of the cemented carbide substrate. An (Al, Ti, Si) N layer is deposited as a lower layer with an average layer thickness of 1 to 5 μm, and then arc discharge between the cathode electrode (evaporation source) and anode electrode of both the Al—Ti—Si alloys. In the same manner, an arc discharge is generated between the metal V as the cathode electrode (evaporation source) and the anode electrode while keeping the atmosphere in the apparatus in the nitrogen atmosphere, and the VN layer is set to 0. 1-1 After vapor deposition with an average layer thickness of 5 μm, arc discharge between the metal V and the anode electrode is stopped, and when the atmosphere in the vapor deposition apparatus is switched to an oxygen atmosphere, the cathode electrode (evaporation source) is used again. by generating arc discharge between a certain metal V and the anode electrode, with an average layer thickness 1~5μm as the upper layer overlaid on the VN layer can be formed by depositing VO _M layer.

(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 of difficult-to-cut materials such as (Al, Ti, Si) N layer, the lower layer has excellent high-temperature hardness and heat resistance, and excellent high-temperature strength. sex becomes that further improved by coexistence content of Si component, and the action of VO _M layer excellent adhesion bonding property is secured between the lower layer by interposition of VN layer as an interlayer adhesion layer, wherein Excellent surface slipperiness is ensured between difficult-to-cut materials and chips, and cutting and sticking of the difficult-to-cut materials and chips to the surface of the cutting edge are significantly reduced. The cutting edge No chipping is generated, and excellent wear resistance is 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),
A lower layer composed of an (Al, Ti, Si) N layer, 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 VN layer having an average layer thickness of 0.1 to 1.5 μm;
(C) an upper layer composed of VO _M layer having an average layer thickness of 1 to 5 [mu] m,
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 the highest Al content point (Al, Ti, Si) The Al component of the N layer improves the high-temperature hardness and heat resistance, and the Ti component improves the high-temperature strength. The Si component has the effect of further improving the heat resistance. Therefore, it has excellent high-temperature hardness and heat resistance at the highest Al content point where the Al component content is relatively high, and it is excellent in high-speed cutting with high heat generation. However, when the X value indicating the proportion of Ti is less than 0.10 in the total amount of Al and Si (atomic ratio), the proportion of Al increases relatively. Thus, even if there is an adjacent Al minimum content point having a relatively high high-temperature strength, the strength of the layer itself is inevitably reduced. As a result, chipping and the like are likely to occur, while the ratio of the Ti component is shown. When the X value exceeds 0.35, On the other hand, the proportion of Al becomes too small, and the desired excellent high-temperature hardness and heat resistance cannot be secured, and the Y value indicating the proportion of Si component accounts for the total amount of Al and Ti ( If the 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. 10 to 0.35 and Y value were determined to be 0.01 to 0.10, respectively.

(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.

VO _M layer constituting the average layer thickness top layer of (C) the upper layer has excellent surface slipperiness, as described above workpiece tack and reactivity to (difficult-to-cut materials) and chips are very This is low, and this is maintained without change even when the workpiece is heated at the time of cutting. Therefore, the (Al, Ti, Si) N layer, which is the lower layer, is separated from the workpiece heated and cut at the high temperature. Protects from powder and exerts an action of suppressing the occurrence of chipping. However, if the average layer thickness is less than 1 μm, a desired effect cannot be obtained in the above action, while the average layer thickness exceeds 5 μm. If it is too much, chipping is likely to occur, so the average layer thickness was set to 1 to 5 μm.

In the coated carbide tool of the present invention, the lower (Al, Ti, Si) N layer constituting the hard coating layer has excellent high temperature hardness and heat resistance, and excellent high temperature strength, and adhesion between the same layers. by VO _M layer as an upper layer was firmly adhered joined by VN layer as a layer, since the superior surface slipperiness between the workpiece (difficult-to-cut materials) and chips is ensured, in particular viscosity and Excellent chipping resistance and excellent wear resistance over a long period even in high-speed cutting with high heat generation of difficult-to-cut materials such as highly sticky stainless steel, high manganese steel, and mild steel Is.

  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 / TiCN-based cemented carbide substrates B-1 to B-6 having a chip shape of CNMG120408 were formed.

(A) Next, each of the above carbide substrates A-1 to A-10 and B-1 to B-6 was ultrasonically cleaned in acetone and dried, and then the arc ion plate shown in FIG. Attached along the outer periphery at a predetermined distance in the radial direction from the central axis on the rotary table in the coating apparatus, sandwiching the rotary table, the uppermost Al of the lower layer as the cathode electrode (evaporation source) on one side Al-Ti-Si alloy for containing point formation, Al-Ti-Si alloy for forming the lowest Al content point of the lower layer on the other side is also arranged oppositely, and further along the rotary table and the Al-Ti-Si Similarly, an interlayer adhesion layer and an upper layer forming metal V are disposed as cathode electrodes (evaporation sources) at positions 90 degrees away from each of the alloys,
(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 has 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 Al-Ti alloys for forming the lower layer is stopped, and the atmosphere in the apparatus is similarly maintained in a 4 Pa nitrogen atmosphere. Under the condition that the DC bias voltage is also -100 V, an arc discharge is generated by flowing a current of 120 A between the metal V of the cathode electrode and the anode electrode, and the target layer thicknesses shown in Tables 3 and 4 are also obtained. VN layer is vapor-deposited as an interlayer adhesion layer of a hard coating layer,
(E) When the arc discharge between the metal V and the anode electrode is stopped and the atmosphere in the vapor deposition apparatus is switched to an oxygen atmosphere of 0.2 Pa, it is again between the metal V and the anode electrode of the cathode electrode. by flowing a 120A current to generate arc discharge, also by the VO _M layer of the target layer thicknesses shown in tables 3 to deposit formed as an upper layer of the hard coating layer, the present as the present invention coated cemented carbide Invention surface coated carbide throwaway tips (hereinafter referred to as the present invention coated tips) 1 to 16 were produced.

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 2 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, by depositing a (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 carbide throw-away 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: 330 m / min. ,
Cutting depth: 2mm,
Feed: 0.25 mm / rev. ,
Cutting time: 8 minutes
Dry continuous high-speed cutting test of mild steel under the conditions (cutting condition A) (normal cutting speed is 200 m / min.),
Work material: JIS / SUS316 lengthwise equidistant 4 round grooved round bars,
Cutting speed: 280 m / min. ,
Incision: 3mm,
Feed: 0.3 mm / rev. ,
Cutting time: 7 minutes
A dry intermittent high-speed cutting test of stainless steel under the conditions (cutting condition B) (normal cutting speed is 180 m / min.),
Work material: JIS · SCMnH1 lengthwise equidistant four round grooved round bars,
Cutting speed: 250 m / min. ,
Incision: 1.5mm,
Feed: 0.2 mm / rev. ,
Cutting time: 10 minutes,
Of high manganese steel under normal conditions (cutting condition C) (normal cutting speed is 150 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.

Then, 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 arc ion plating apparatus shown in FIG. 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 9 along the layer thickness direction alternately and repeatedly exist at the target interval shown in Table 9, and It has 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 also shown in Table 9 target layer thickness to be (Al, Ti, Si) and a lower layer made of N layers, likewise rigid made up of an upper layer consisting of interlayer adhesion layer and VO _M layer comprising a target layer thickness of the VN layer shown in Table 9 By forming a coating layer by vapor deposition Thus, the surface coated carbide end mills (hereinafter referred to as the present invention coated end mills) 1 to 8 as the present invention coated carbide tools were produced, respectively.

  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 surface coating as a conventional coated carbide tool is obtained by evaporating a (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 coated layer. Carbide end Le (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-planar dimensions: 100 mm × 250 mm, thickness: 50 mm JIS / SCMnH1 plate material,
Cutting speed: 60 m / min. ,
Groove depth (cut): 2.5 mm,
Table feed: 150 mm / min,
The high-manganese steel dry high-speed grooving test (normal cutting speed is 30 m / min.), The present 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: 70 m / min. ,
Groove depth (cut): 5.5 mm,
Table feed: 220 mm / min,
With respect to the dry high-speed grooving test of mild steel under the conditions (normal cutting speed is 40 m / min.), The coated end mills 7 and 8 of the present invention and the conventional coated end mills 7 and 8 are as follows:
Work material-Plane dimensions: 100 mm x 250 mm, thickness: 50 mm JIS / SUS316 plate material,
Cutting speed: 65 m / min. ,
Groove depth (cut): 8 mm,
Table feed: 200 mm / min,
Stainless steel dry high-speed grooving test (normal cutting speed is 30 m / min.) Under the above conditions, and the flank wear width of the outer peripheral edge of the cutting edge is the service life of each grooving test. The cutting groove length up to 0.1 mm as a standard 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 the arc ion plating apparatus shown in FIG. 1 is also used. In the same conditions as in Example 1 above, the target minimum distance between the Al minimum content point and the Al maximum content point of the target composition shown in Table 11 along the layer thickness direction is also shown in Table 11 alternately. And having 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 also the target layer thickness as indicated in Table 11 (Al, Ti, Si) and N layer lower layer consisting of an upper, which also consists of interlayer adhesion layer and VO _M layer comprising a target layer thickness of the VN layer shown in Table 11 Hard coating composed of layers The surface-coated carbide drills (hereinafter referred to as the present invention-coated drills) 1 to 8 as the present invention-coated carbide tools were produced by depositing layers.

  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 (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. Conventional surface as a tool Covering 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-Plane dimensions: 100 mm x 250 mm, thickness: 50 mm JIS / SUS316 plate material,
Cutting speed: 130 m / min. ,
Feed: 0.2mm / rev,
Hole depth: 10mm,
For the wet high speed drilling machining test of stainless steel under the conditions of (normal cutting speed is 80 m / min.), The present invention coated drills 4-6 and the conventional coated drills 4-6,
Work material-planar dimensions: 100 mm × 250 mm, thickness: 50 mm JIS / SCMnH1 plate material,
Cutting speed: 120 m / min. ,
Feed: 0.3mm / rev,
Hole depth: 14mm,
For the high-manganese steel wet high speed drilling test (normal cutting speed is 60 m / min.), The present invention coated drills 7 and 8 and the conventional coated drills 7 and 8,
Work material-planar dimensions: 100 mm x 250 mm, thickness: 50 mm JIS / S15C plate,
Cutting speed: 170 m / min. ,
Feed: 0.25mm / rev,
Hole depth: 30mm,
Wet high-speed drilling test of mild steel under normal conditions (normal cutting speed is 50 m / min.), And any wet high-speed drilling test (using water-soluble cutting oil) is used to relieve the cutting edge surface. The number of drilling processes until the surface wear width reached 0.3 mm was measured. The measurement results are shown in Tables 11 and 12, respectively.

  The hard coating layers of the present coated chips 1-16, the present coated end mills 1-8, and the present coated drills 1-8 as the present coated carbide tool obtained as a result (Al, Ti, Si) ) From the composition of the N layer (lower layer) and the conventional coated tips 1-16 as a conventional coated carbide tool, the conventional coated end mills 1-8, and the (Al, Ti, Si) N layer of the conventional coated drills 1-8 When the composition of the resulting hard coating layer was measured by energy dispersive X-ray analysis using a transmission electron microscope, it showed substantially the same composition as the target composition.

Furthermore, when VO _M layer constituting the hard layer of the present invention coated cemented carbide composition of (upper layer) was also measured, by atomic ratio, mainly the VO, this _{VO, V 2 O 3, V} 2 A mixed structure containing O ₅ , VO _{2 and the} like was shown.

  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 (Al, Ti, Si) N layer, which is the lower layer of the hard coating layer, has excellent high-temperature hardness and heat resistance, and excellent high-temperature strength, and the lower layer is formed by the VN layer as an interlayer adhesion layer. by VO _M layer firmly adhered to the layer, the resistance from the superior surface slipperiness between the workpiece and chips is ensured, without the occurrence of chipping in the cutting edge, which is excellent for a long period In the conventional coated carbide tool in which the hard coating layer is composed of an (Al, Ti, Si) N layer, while exhibiting wear, all of the work materials ( Difficult-to-cut materials) and chips and the hard coating layer It is clear that the adhesiveness and reactivity 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 arc ion plating apparatus used for 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. It is a schematic explanatory drawing of a normal arc ion plating apparatus.

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) an upper layer comprising a vanadium oxide layer having an average layer thickness of 1 to 5 μm,
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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