JP2007030068A - Cutting tool made of surface coated cemented carbide having hard coated 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 coated layer exhibiting excellent chipping resistance in high-speed cutting a material hard to cut. <P>SOLUTION: A hard coated layer formed of following layers (a) to (c) is formed on the surface of cemented carbide base body: (a) a lower layer formed of (Al, Ti)N layer having an average layer thickness ranging from 1 to 15 μm, and having a component concentration distribution structure in which Al maximum content points and Al minimum content points alternately repeatedly exist at predetermined intervals along the direction of layer thickness, the Al content and Ti content respectively continuously vary from the Al maximum content point to the Al minimum content point, and from the Al minimum content point to the Al maximum content point, the Al maximum content point and the Al minimum content point satisfy a specified composition formula, and the interval between the adjacent Al maximum content point and the Al minimum content point is 0.01 to 0.1 μm; (b) an inter-layer contact layer formed of vanadium nitride layer having an average layer thickness ranging from 0.1 to 1.5 μm; and (c) an upper layer formed of vanadium oxide layer having an average layer thickiness ranging from 1 to 5 μm. <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 Ti X} ) N ( provided that an atomic ratio, X is shows the 0.05 to 0.30),
The Al minimum content point is a composition formula: (Al _1-Y Ti _Y ) N (where Y represents 0.35 to 0.60 in atomic ratio),
Satisfied,
In addition, an Al and Ti composite nitride layer [hereinafter referred to as (Al, Ti) N] layer in which the interval between the adjacent Al highest content point and Al lowest content point is 0.01 to 0.1 μm, A coated carbide tool formed by physically vapor-depositing a hard coating layer is known, and the (Al, Ti) N layer, which is a hard coating layer of the coated carbide tool, is excellent due to Al having a component concentration distribution change structure. High temperature hardness and heat resistance, as well as excellent high temperature strength due to the same Ti, of course, when used to perform continuous cutting and intermittent cutting of various general steels and ordinary cast iron under normal conditions In addition, it is also known that excellent cutting performance is exhibited even when this is used for high-speed cutting.

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 mounting turntable is provided, with the turntable sandwiched therebetween, an Al-Ti alloy having a relatively high Al content (low Ti content) on one side and a relatively high Ti content (Al on the other side) Using an arc ion plating apparatus in which an Al—Ti alloy having a low content is disposed as a cathode electrode (evaporation source), a position on the rotary table of the apparatus that is a predetermined distance in the radial direction from the central axis thereof A plurality of carbide substrates are mounted in a ring shape in this state, and in this state, the atmosphere inside the apparatus is changed to a nitrogen atmosphere, the rotary table is rotated, and the thickness of the hard coating layer formed by vapor deposition is made uniform. An arc discharge is generated between the cathode electrode (evaporation source) and the anode electrode on both sides while rotating the substrate itself, thereby forming an (Al, Ti) N layer on the surface of the carbide substrate. In the (Al, Ti) N layer formed as a result, the cemented carbide substrate arranged in a ring shape on the rotary table has a relatively high Al content on one side ( At the point closest to the cathode electrode (evaporation source) of the Al-Ti alloy (low Ti content), the highest Al content point is formed in the layer, and the carbide substrate is relatively Ti-containing on the other side. At the point closest to the cathode electrode of the Al-Ti alloy having a high amount (low Al content), the lowest Al content point is formed in the layer, and the rotation of the rotary table causes the layer to move along the layer thickness direction. Al maximum content point and Al A component in which low content points appear alternately and repeatedly at predetermined intervals, and Al and Ti content continuously change from the Al maximum content point to the Al minimum content point, and from the Al minimum content point to the Al maximum content point. A concentration distribution structure is formed.
Japanese Patent No. 3669334

  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) 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 a vanadium oxide (hereinafter referred to as VO) as an upper layer thereon. _M represents a change value of the relative content ratio of oxygen to vanadium (V), and the atomic ratio indicates VO, V ₂ O ₃ , V ₂ O ₅ , VO _2, etc.) cutting edge to form 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 part (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, and the work material and the cutting edge part of the chip The adhesiveness and reactivity to the surface is significantly reduced, the lower layer ( l, Ti) N-layer because it sufficiently protect, (Al, Ti) 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) adhesion to the N layer is not sufficient, because the insufficient adhesion between layers, particularly when subjected to intermittent cutting Although in chipping occurs easily, the VO _M layer (Al, Ti) vanadium nitride between the N layer (hereinafter, indicated by VN) when interposing the layer with an average layer thickness of 0.1~1.5μm , wherein the the VN layer VO _M layer and (Al, Ti) since also firmly adhered to one of the N layer, 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 carbide substrate is provided in the center of the apparatus, and an Al—Ti alloy with a relatively high Al content (low Ti content) is placed on one side and the other side is placed with the turning table sandwiched between them. In particular, an Al—Ti alloy having a high Ti content (low Al content) is arranged as a cathode electrode (evaporation source), and the cathode electrode (evaporation) is positioned 90 degrees away from each of the two Al—Ti alloys. An arc ion plating apparatus in which metal V (vanadium) is disposed as a source), and a plurality of cemented carbide substrates are disposed along the outer peripheral portion at a predetermined radial distance from the central axis on the rotary table of the apparatus. Re In this state, the atmosphere inside the apparatus is changed to a nitrogen atmosphere, the rotary table is rotated, and the carbide substrate itself is rotated for the purpose of uniforming the thickness of the hard coating layer formed by vapor deposition. Specifically, first, arc discharge is generated between the cathode electrode (evaporation source) and the anode electrode of both the Al-Ti alloys arranged opposite to each other as a lower layer (Al, Ti) on the surface of the cemented carbide substrate. The N layer is deposited with an average layer thickness of 1 to 5 μm, and then the arc discharge between the cathode electrode (evaporation source) and the anode electrode of both the Al—Ti alloys is stopped, and the atmosphere in the apparatus is changed to a nitrogen atmosphere. While holding, an arc discharge was generated between the metal V as the cathode electrode (evaporation source) and the anode electrode, and a VN layer was deposited as an interlayer adhesion layer with an average layer thickness of 0.1 to 1.5 μm. After 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 the oxygen atmosphere, the arc discharge is again performed between the metal V as the cathode electrode (evaporation source) and the anode electrode. that can be a by generating, formed by depositing VO _M layer with an average layer thickness of 1~5μm as an upper layer overlapping the VN 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) N layer, the lower layer has excellent high-temperature hardness and heat resistance, and excellent high-temperature strength, and an interlayer adhesion layer wherein the action of VO _M layer excellent adhesion bonding property is secured between the lower layer, excellent surface slipperiness between the flame cut materials and chips is ensured by the interposition of VN layer as, Since the cutting and cutting of the difficult-to-cut material and the chips to the surface of the cutting edge portion are significantly reduced, chipping does not occur in the cutting edge portion and can be used for a long time. Excellent wear resistance To be like that.
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 Ti X} ) N ( provided that an atomic ratio, X is shows the 0.05 to 0.30),
The Al minimum content point is a composition formula: (Al _1-Y Ti _Y ) N (where Y represents 0.35 to 0.60 in atomic ratio),
A lower layer composed of an (Al, Ti) N layer, wherein the interval between the Al highest content point and the Al minimum 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,
It is characterized by a coated cemented carbide tool that forms a hard coating layer composed of the above (a) to (c) and exhibits excellent chipping resistance in cutting of difficult-to-cut materials. is there.

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 in the (Al, Ti) N layer improves high-temperature hardness and heat resistance, while Ti is included for the purpose of improving high-temperature strength. Therefore, if the Ti ratio (X value) at the highest Al content point is less than 0.05 in terms of the total amount with Al (atomic ratio), the Ti ratio becomes too low and the high-temperature strength suddenly increases. When the ratio (X value) exceeds 0.30, the Al ratio becomes too low and the desired excellent high-temperature hardness. And since the heat resistance could not be ensured, the ratio was determined to be 0.05 to 0.30.

(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 (Y value) is If the ratio (atomic ratio) to the total amount with Al is less than 0.35, the desired excellent high-temperature strength cannot be secured, while if the ratio (Y value) also exceeds 0.60, In particular, the proportion of Ti is excessively increased, and the minimum Al content point cannot be provided with the desired high-temperature hardness and heat resistance. Therefore, the proportion is set to 0.35 to 0.60.

(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. When it becomes impossible to secure the characteristics and high temperature strength and the interval exceeds 0.1 μm, the disadvantages of each point, that is, when the Al highest content point is insufficient high temperature strength, when the Al minimum content point is high temperature characteristics The shortage appears locally in the layer, and this makes it easier for chipping to occur on the cutting edge and promotes the progress of wear, so the interval was set to 0.01 to 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 since the work material is maintained without being changed even when the work material is heated at the time of cutting, the lower layer (Al, Ti) N layer is separated from the work material and chips heated at the high temperature. Protects and suppresses the occurrence of chipping, but if the average layer thickness is less than 1 μm, the desired effect cannot be obtained in the above-described operation, while if the average layer thickness exceeds 5 μm and becomes too thick. Since the chipping is likely to occur, the average layer thickness is determined to be 1 to 5 μm.

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

  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 alloy for forming contained points, Al-Ti alloy for forming the lowest Al content point of the lower layer on the other side are arranged opposite to each other, and further along the rotary table and 90 degrees from each of the Al-Ti alloys. Similarly, the interlayer adhesion layer and the upper layer forming metal V are arranged as cathode electrodes (evaporation sources) at remote positions,
(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. A DC bias voltage is applied, and an arc discharge is generated by flowing a current of 100 A between either one of the two Al-Ti alloys for forming the lower layer of the cathode electrode and the anode electrode. The substrate surface is bombarded with the Al-Ti alloy,
(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 alloy for forming the highest Al content point and the Al-Ti alloy for forming the lowest Al content point) and the anode electrode. On the surface of the hard 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 are alternately present at the target intervals shown in Tables 3 and 4 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 , (Al, Ti) having a target layer thickness shown in 4 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. The Al-Ti alloy for forming an Al minimum content point having various component compositions as a cathode electrode (evaporation source) on one side, and various component compositions as a cathode electrode (evaporation source) on the other side Al-Ti alloy for forming the highest Al content point with a facing arrangement 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 A current of 100 A is passed between either one of the two Al—Ti alloys of the cathode electrode and the anode electrode to generate an arc discharge, whereby the carbide substrate surface is bombarded with the Al—Ti alloy,
(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 alloy for forming the lowest Al content point and the Al-Ti alloy for forming the highest Al content point) and the anode electrode. On the surface of the hard substrate, the Al minimum content point and the Al maximum content point of the target composition shown in Tables 5 and 6 are alternately repeated at the target intervals shown in Tables 5 and 6 along the layer thickness direction, 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 , 6 by depositing a (Al, Ti) N layer corresponding to the lower layer of the above-described coated chip of the present invention as a hard coating layer, thereby producing a conventional surface-coated carbide as a conventional coated carbide tool. Slow away chips (hereinafter referred to as conventional coated chips) 1 to 16 were produced.

Next, in the state where each of the above various coated chips is screwed to the tip of the tool steel tool with a fixing jig, the present coated chips 1 to 16 and the conventional coated chips 1 to 16 are as follows.
Work material: JIS / SUS316 lengthwise equidistant 4 round grooved round bars,
Cutting speed: 350 m / min. ,
Incision: 1.5mm,
Feed: 0.3 mm / rev. ,
Cutting time: 10 minutes,
A dry intermittent high-speed cutting test of stainless steel under the conditions (cutting condition A) (normal cutting speed is 180 m / min.),
Work material: JIS / S15C lengthwise equal length 4 vertical grooved round bars,
Cutting speed: 300 m / min. ,
Cutting depth: 2mm,
Feed: 0.4 mm / rev. ,
Cutting time: 5 minutes
Dry interrupted high-speed cutting test of mild steel under the conditions (cutting condition B) (normal cutting speed is 200 m / min.),
Work material: JIS / SCMnH1 round bar,
Cutting speed: 230 m / min. ,
Incision: 1.5mm,
Feed: 0.3 mm / rev. ,
Cutting time: 8 minutes
The dry continuous high-speed cutting test (normal cutting speed is 150 m / min.) Of high manganese steel under the above conditions (cutting condition C), and the flank wear width of the cutting edge was measured in any cutting test. . The measurement results are shown in Table 7.

As raw material powders, medium coarse WC powder having an average particle diameter of 5.5 μm, fine WC powder of 0.8 μm, TaC powder of 1.3 μm, NbC powder of 1.2 μm, ZrC of 1.2 μm Powder, 2.3 μm Cr ₃ C ₂ powder, 1.5 μm VC powder, 1.0 μm (Ti, W) C [by mass ratio, TiC / WC = 50/50] powder, and 1 Prepare 8 μm Co powder, mix these raw material powders with the composition shown in Table 8, add wax, ball mill in acetone for 24 hours, dry under reduced pressure, and press at a pressure of 100 MPa. The green compacts were press-molded, and these green compacts were heated to a predetermined temperature in the range of 1370 to 1470 ° C. at a rate of temperature increase of 7 ° C./min in a 6 Pa vacuum atmosphere. After holding at temperature for 1 hour, sintering under furnace cooling conditions 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 of (Al, Ti) which is a lower layer consisting of N layers and, likewise hard layer composed of a top layer made of a target layer thickness interlayer adhesion layer and VO _M layer made of VN layer shown in Table 9 By evaporating and forming the book The surface-coated carbide end mills (hereinafter referred to as the present invention-coated end mills) 1 to 8 as the 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-coated carbide as a conventional coated carbide tool is obtained by evaporating a (Al, Ti) N layer corresponding to the lower layer of the above-mentioned coated end mill of the present invention having a target layer thickness shown in Table 10 as a hard coated layer. End mill ( Under conventional coated end mill say) 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 x 250 mm, thickness: 50 mm JIS / S15C plate,
Cutting speed: 75 m / min. ,
Groove depth (cut): 3 mm,
Table feed: 160 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 4 to 6 and the conventional coated end mills 4 to 6 of the present invention,
Work material-Plane dimensions: 100 mm x 250 mm, thickness: 50 mm JIS / SUS316 plate material,
Cutting speed: 80 m / min. ,
Groove depth (cut): 4.5 mm,
Table feed: 200 mm / min,
Stainless steel wet (using water-soluble cutting oil) high-speed grooving test (normal cutting speed is 40 m / min.), Coated end mills 7 and 8 of the present invention, and conventional coated end mills 7 and 8
Work material-planar dimensions: 100 mm × 250 mm, thickness: 50 mm JIS / SCMnH1 plate material,
Cutting speed: 55 m / min. ,
Groove depth (cut): 10 mm,
Table feed: 120 mm / min,
The high-manganese-steel dry high-speed grooving test (normal cutting speed is 30 m / min.) Under the above conditions was performed. 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 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 of the target layer thicknesses shown in Table 11 (Al, Ti) and a lower layer made of N layers, also in the upper layer consisting of interlayer adhesion layer and VO _M layer made of VN layer of the target layer thicknesses shown in Table 11 Steam the constructed hard coating layer By forming these, drills made of the surface coated carbide of the present invention (hereinafter referred to as the present invention coated drills) 1 to 8 as the coated carbide tools of the present invention 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 (Al, Ti) 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 as a hard coating layer. Conventional surface coating Ltd. drill (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: 8mm,
With respect to the wet high speed drilling test of stainless steel under the conditions (normal cutting speed is 50 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: 0.25mm / rev,
Hole depth: 16mm,
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: 100 m / min. ,
Feed: 0.3mm / rev,
Hole depth: 32mm,
Wet high-speed drilling test of mild steel under normal conditions (normal cutting speed is 60m / 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.

  (Al, Ti) N constituting the hard coating layer 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 Hard coating layer comprising the composition of the layer (lower layer) and the conventional coated tip 1-16 as a conventional coated carbide tool, the conventional coated end mill 1-8, and the (Al, Ti) N layer of the conventional coated drill 1-8 Were measured by an energy dispersive X-ray analysis method using a transmission electron microscope, and 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 _{V 2 O 3, V 2 O} 5 , And a mixed structure containing VO ₂ or the like.

  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) 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, the since the superior surface slipperiness between the workpiece and chips is ensured, without the occurrence of chipping in the cutting edge, wear resistance superior over a long period In contrast, in the conventional coated carbide tool in which the hard coating layer is composed of an (Al, Ti) N layer, all of the above-mentioned difficult-to-cut materials are subjected to high-speed cutting work (hard-to-cut materials). And the adhesiveness between the chips and the hard coating layer, and It is clear that the reactivity is 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. 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 Ti X} ) N ( provided that an atomic ratio, X is shows the 0.05 to 0.30),
The Al minimum content point is a composition formula: (Al _1-Y Ti _Y ) N (where Y represents 0.35 to 0.60 in atomic ratio),
A lower layer made of a composite nitride layer of Al and Ti, 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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