JP2007030108A - Gear cutting tool made of surface coated cemented carbide having hard coarted layer exhibiting excellent chipping resistance in hard 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 hard 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 (d) is formed on the surface of a tungsten carbide-base body or a titanium carbide nitride-base cermet base body: (a) a base body contact layer formed of (Ti, Al)N layer having an average layer thickness ranging from 0.5 to 2 μm and satisfying the composition formula: (Ti<SB>1-Z</SB>Al<SB>Z</SB>)N (wherein Z is 0.30 to 0.70 in an atomic ratio); (b) a lower layer formed of (Ti, Al, B)N layer having an average layer thickness ranging grom 1 to 5 μm and satisfying the composition formula (Ti<SB>1-(X+Y)</SB>Al<SB>X</SB>B<SB>Y</SB>)N (wherein X is 0.40 to 0.70 and Y is 0.01 to 0.20 in an atomic ratio); (c) an inter-layer contact layer formed of a vanadium nitride layer having an average layer thickness ranging from 0.1 to 1.5 μm; and (d) an upper layer formed of a vanadium oxide layer having an average layer thickness 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 heavy cutting conditions such as high cutting and high feed. 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,
Ti satisfying the composition formula: (Ti _{1- (X + Y)} Al _X B _Y ) N (wherein X is 0.40 to 0.70 and Y is 0.01 to 0.20 in atomic ratio) Known is a coated carbide tool formed by physical vapor deposition of a hard coating layer composed of a composite nitride of Al and B (boron) (hereinafter referred to as (Ti, Al, B) N) with an average layer thickness of 1 to 15 μm. And the (Ti, Al, B) N layer, which is a hard coating layer of the coated carbide tool, has high temperature hardness and heat resistance due to Al as a constituent component, high temperature strength due to the Ti, and B It is also known that when it is used for continuous cutting and intermittent cutting of various general steels and ordinary cast iron, it exhibits excellent cutting performance because it has been further improved in high-temperature hardness by the inclusion of It has been.

Furthermore, the above-mentioned coated carbide tool is, for example, the above-mentioned carbide substrate is inserted into an arc ion plating apparatus which is one type of physical vapor deposition apparatus schematically shown in FIG. For example, an arc discharge is generated between the anode electrode and a cathode electrode (evaporation source) on which a Ti—Al—B alloy having a predetermined composition is set, for example, at a current of 90 A, while being heated to a temperature of 500 ° C. At the same time, nitrogen gas is introduced into the apparatus as a reaction gas to form a reaction atmosphere of, for example, 2 Pa. On the other hand, the carbide substrate is applied to the surface of the carbide substrate under a condition that a bias voltage of, for example, −100 V is applied. It is also known that it is produced by vapor-depositing a hard coating layer composed of the (Ti, Al, B) N layer.
Japanese Patent No. 2793696

  In recent years, the use of FA for cutting devices has been remarkable. On the other hand, there is a strong demand for labor saving, energy saving, and cost reduction for cutting processing. There is a tendency to demand cutting tools that can cut as many grades as possible, but in the above-mentioned conventional coated carbide tools, this is applied to general steels such as low alloy steels and carbon steels. There is no problem when used for cutting of ordinary cast iron such as ductile cast iron and gray cast iron, but especially stainless steel, high manganese steel, and mild steel with high chip viscosity and easy welding to the tool surface. When cutting difficult-to-cut materials (work materials) under heavy cutting conditions such as high cutting and high feed, where the load is locally applied to the cutting edge, the work material and Chips are heated As a result, the viscosity further increases, and as a result, not only the adhesion and reactivity to the surface of the hard coating layer further increase, but also the (Ti, Al, B) N layer which is a hard coating layer. Since the adhesiveness to the substrate surface is not sufficient, in the cutting of the difficult-to-cut material under heavy cutting conditions, the occurrence of chipping (small chipping) in the cutting edge portion increases rapidly, and this causes a relatively short time. At present, the service life is reached.

In view of the above, the present inventors have demonstrated excellent chipping resistance with a hard coating layer, particularly when cutting difficult-to-cut materials under heavy cutting conditions such as high cutting and high feed. As a result of conducting research focusing on the above-mentioned conventional coated carbide tools,
(A) A (Ti, Al, B) 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 (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, and the atomic ratio indicates VO, V ₂ O ₃ , V ₂ O ₅ , VO _2, etc.) by forming an average layer thickness of 5 .mu.m, the VO _M layer is excellent surface slipperiness, cutting edge even when the result workpiece by heat generated during cutting (difficult-to-cut materials) and its cutting scraps is high temperature heating Excellent slidability is always ensured between the rake face and the flank face and the cutting edge ridge line where both of the surfaces intersect, and the work material and the chip. The lower layer (T , Al, B) an N layer from the fully protected, (Ti, Al, B) 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 (Ti, Al, B) 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 (Ti, Al, B) 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 (Ti, Al, B) from that firmly adhered with any of the N layer, it comes to be ensured good adhesion to both of these layers .

(C) Also, as described above, the adhesion of the (Ti, Al, B) N layer to the carbide substrate surface is not sufficiently satisfactorily resistant to cutting under difficult cutting conditions under heavy cutting conditions. A composite nitride layer of Ti and Al that does not contain a B component (hereinafter referred to as (Ti, Al) N) has a composition formula: (Ti _{1 -Z} Al _Z ) N (wherein Z is 0 in terms of atomic ratio) .30 to 0.70) and with an average layer thickness of 0.5 to 2 μm, the (Ti, Al) N layer is formed on the surface of the carbide substrate and (Ti, Al, B). ) Since both N layers are firmly adhered to each other, excellent adhesion can be secured between them.

(D) The hard coating layer of (c) above is, for example, an arc ion plating apparatus having a structure shown in a schematic plan view in FIG. 1A and a schematic front view in FIG. A rotation table for mounting a hard substrate is provided, and a Ti-Al-B alloy having a predetermined composition as a cathode electrode (evaporation source) is provided on one side with the rotation table interposed therebetween, and a predetermined cathode electrode (evaporation source) is also provided on the other side. And a metal as a cathode electrode (evaporation source) at a position 90 degrees away from each of the Ti-Al-B alloy and Ti-Al alloy along the rotary table. The arc ion plating apparatus having V is used, and a plurality of cemented carbide substrates are bonded along the outer peripheral portion at a predetermined distance in the radial direction from the central axis on the rotary table of the apparatus. 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. First, an arc discharge is generated between the cathode electrode (evaporation source) and the anode electrode of the Ti—Al alloy, and a (Ti, Al) N layer is formed as a substrate adhesion layer on the surface of the cemented carbide substrate. After vapor deposition with an average layer thickness of 0.5 to 2 μm, the arc discharge between the cathode electrode (evaporation source) of the Ti—Al alloy and the anode electrode was stopped, and the atmosphere in the apparatus was continuously maintained in a nitrogen atmosphere. Then, an arc discharge is generated between the cathode electrode (evaporation source) and the anode electrode of the Ti—Al—B alloy, and the (Ti, Al, B) N layer is an average layer thickness of 1 to 5 μm as a lower layer. Vapor deposition and then before The arc discharge between the cathode electrode (evaporation source) of the Ti—Al—B alloy and the anode electrode is stopped, and the metal V serving as the cathode electrode (evaporation source) is kept in the same nitrogen atmosphere. An arc discharge is generated between the anode electrode and a VN layer is deposited as an interlayer adhesion layer with an average layer thickness of 0.1 to 1.5 μm, and then the arc discharge between the metal V and the anode electrode is stopped. Then, when the atmosphere in the vapor deposition apparatus is switched to the oxygen atmosphere, an arc discharge is generated again between the metal V as the cathode electrode (evaporation source) and the anode electrode, and the upper layer is superimposed on the VN layer. it can be formed by depositing VO _M layer with an average layer thickness of 1~5μm as.

(E) Coated carbide tools formed by vapor-depositing a hard coating layer composed of the above-mentioned substrate adhesion layer, lower layer, interlayer adhesion layer, and upper layer are stainless steel and high manganese, which are particularly highly viscous and sticky. Even when cutting difficult-to-cut materials such as steel and mild steel under heavy cutting conditions such as high cutting with high load and high feed, it is firmly bonded to the surface of the carbide substrate through the substrate adhesion layer. The (Ti, Al, B) N layer, which is the lower layer, has excellent high temperature hardness and heat resistance, and excellent high temperature strength, and is superior to the lower layer by interposing the VN layer as an interlayer adhesion layer. in the action of VO _M layer adhesion bonding property is ensured, excellent surface slipperiness between the flame cut materials and chips is ensured, adhesion to the cutting edge surface of the flame-cut materials and chips And the cutting process with significantly reduced reactivity. Since this is done, chipping at the cutting edge is eliminated, and excellent wear resistance is exhibited over a long period of time.
The research results shown in (a) to (e) above were obtained.

This invention was made based on the above research results, and on the surface of the carbide substrate,
(A) having an average layer thickness of 0.5 to 2 μm and a composition formula: (Ti _1-Z Al _Z ) N (wherein Z represents 0.30 to 0.70 in atomic ratio) A substrate adhesion layer comprising a satisfactory (Ti, Al) N layer;
(B) having an average layer thickness of 1 to 5 μm, and a composition formula: (Ti _{1− (X + Y)} Al _X B _Y ) N (however, in terms of atomic ratio, X is 0.40 to 0.70, Y Is a lower layer composed of a (Ti, Al, B) N layer satisfying 0.01 to 0.20),
(C) an interlayer adhesion layer comprising a VN layer having an average layer thickness of 0.1 to 1.5 μm;
(D) 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 excellent chipping resistance in heavy cutting of difficult-to-cut materials, formed by forming a hard coating layer composed of (a) to (d) 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) Composition of substrate adhesion layer and average layer thickness In the (Ti, Al, B) N layer as the lower layer, the B component further improves the high-temperature hardness of the layer itself, thereby improving the wear resistance. On the other hand, it is a component that lowers the adhesion to the surface of the carbide substrate, in particular, and therefore the (Ti, Al) N layer constituting the substrate adhesion layer does not contain the B component and is a component. A certain Ti action ensures strong adhesion to both the surface of the cemented carbide substrate and the lower layer. On the other hand, with the same Al component, the high-temperature hardness of the layer itself is the same as in the lower layer. In addition, it contributes to improving the wear resistance of the hard coating layer by improving the heat resistance, but the Z value indicating the proportion of Al accounts for the proportion of the total amount with Ti (atomic ratio, the same shall apply hereinafter). When less than 30, the predetermined high temperature hardness and Heat resistance cannot be ensured, which causes a decrease in wear resistance. On the other hand, when the Z value indicating the Al ratio exceeds 0.70, the Ti ratio is relatively less than 0.30. Therefore, the desired excellent adhesion cannot be ensured between the surface of the cemented carbide substrate and the lower layer, so the Z value is set to 0.30 to 0.70.

  Also, if the average layer thickness is less than 0.5 μm, the desired excellent adhesion cannot be secured between the surface of the cemented carbide substrate and the lower layer, while if the average layer thickness exceeds 2 μm, the above viscosity Since heavy cutting of a highly difficult-to-cut material causes a decrease in the wear resistance of the hard coating layer, the average layer thickness is set to 0.5 to 2 μm.

(B) Composition and average layer thickness of the lower layer (Ti, Al, B) The Al component in the N layer is improved in high temperature hardness and heat resistance (high temperature characteristics), and the Ti component is improved in high temperature strength. Furthermore, the B component has the effect of further improving the high temperature hardness, but when the X value indicating the proportion of Al is less than 0.40 in the proportion of the total amount of Ti and B (atomic ratio, the same shall apply hereinafter), The proportion of Ti becomes relatively large, and the predetermined high-temperature hardness and heat resistance cannot be ensured. As a result, the progress of wear is rapidly promoted, while the X value indicating the proportion of Al is If it exceeds 0.70, the proportion of Ti becomes relatively small and the high-temperature strength sharply decreases. As a result, chipping or the like is likely to occur in the cutting edge portion. ~ 0.70, and the ratio of B is shown If the Y value is less than 0.01 in the ratio of the total amount of Al and Ti, the desired high-temperature hardness improvement effect cannot be obtained, while if the Y value exceeds 0.20, the high-temperature strength rapidly decreases. Therefore, the Y value was determined to be 0.01 to 0.20.

  Further, if the average layer thickness is less than 1 μm, it is insufficient to exhibit its excellent wear resistance over a long period of time, whereas if the average layer thickness exceeds 5 μm, the above-mentioned high viscosity is difficult. In the cutting of the cutting material, chipping is likely to occur at the cutting edge, so the average layer thickness was set to 1 to 5 μm.

(C) 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 at 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.

(D) VO _M layer constituting the average layer thickness top layer of the upper layer is excellent has surface slip characteristics were, 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 work material is heated at the time of cutting. Therefore, the (Ti, Al, B) N layer as the lower layer is cut into the work material and the cutting material heated 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 determined to be 1 to 5 μm.

In the coated carbide tool of the present invention, the lower layer (Ti, Al, B) N layer constituting the hard coating layer is firmly attached to the surface of the carbide substrate by the action of the (Ti, Al) N layer which is the substrate adhesion layer. in close contact bonded to, excellent high-temperature hardness and heat resistance, has a more excellent high-temperature strength, and by VO _M layer as an upper layer was firmly adhered joined by VN layer as the interlayer adhesion layer, a work Excellent slipperiness between the material (hard-to-cut material) and the chips is ensured, so that high-load of difficult-to-cut materials such as stainless steel, high manganese steel, and mild steel with high viscosity and stickiness are particularly Even in such heavy cutting, excellent chipping resistance is exhibited, and excellent wear resistance is exhibited over a long period of time.

  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 position that is a predetermined distance in the radial direction from the central axis on the rotary table in the coating apparatus, and has a predetermined composition as a cathode electrode (evaporation source) on one side across the rotary table A Ti—Al—B alloy for forming a lower layer, and a Ti—Al alloy for forming a substrate adhesion layer having a predetermined composition as a cathode electrode (evaporation source) on the other side are arranged opposite to each other. An interlayer adhesion layer and an upper layer forming metal V are disposed as cathode electrodes (evaporation sources) at positions 90 degrees apart 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 applying a current of 100 A between the anode electrode and the Ti—Al alloy for forming the substrate adhesion layer of the cathode electrode to generate an arc discharge, thereby causing the surface of the carbide substrate to adhere to the Ti— Bombarded with Al alloy,
(C) Introducing nitrogen gas as a reaction gas into the apparatus to form a 4 Pa reaction atmosphere, applying a DC bias voltage of −100 V to a carbide substrate rotating while rotating on the rotary table, and a cathode electrode A current of 120 A is passed between the Ti-Al alloy and the anode electrode to generate an arc discharge, so that the surface of the cemented carbide substrate has a target composition and target layer thickness (Ti) shown in Tables 3 and 4. , Al) N layer is formed by vapor deposition as a substrate adhesion layer of a hard coating layer,
(D) The arc discharge between the cathode electrode and the anode electrode of the Ti—Al alloy for forming the substrate adhesion layer is stopped, the atmosphere in the apparatus is maintained in the same nitrogen atmosphere of 4 Pa, and direct current to the carbide substrate is maintained. Similarly, with the bias voltage kept at −100 V, a current of 120 A is passed between the Ti—Al—B alloy of the cathode electrode and the anode electrode to generate an arc discharge. (Ti, Al, B) N layer having a target composition and a target layer thickness shown in 3 and 4 is deposited as a lower layer of the hard coating layer,
(E) The arc discharge between the cathode electrode and the anode electrode of the Ti-Al-B alloy for forming the lower layer is stopped, and the atmosphere in the apparatus is similarly maintained in a nitrogen atmosphere of 4 Pa. Similarly, under the condition that the DC bias voltage is -100 V, a current of 120 A is passed between the metal V of the cathode electrode and the anode electrode to generate arc discharge, and the target layer thicknesses shown in Tables 3 and 4 are also shown. VN layer is deposited as an interlayer adhesion layer of a hard coating layer,
(F) 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 the purpose of comparison, these carbide substrates A-1 to A-10 and B-1 to B-6 were ultrasonically cleaned in acetone and dried, respectively, and the arc ion plate shown in FIG. A Ti-Al-B alloy having various component compositions as a cathode electrode (evaporation source) is inserted into a coating apparatus, and first, the inside of the apparatus is evacuated and maintained at a vacuum of 0.1 Pa or less. After heating the inside of the apparatus to 500 ° C. with a heater, a DC bias voltage of −1000 V is applied to the cemented carbide substrate, and a current of 100 A is passed between the Ti—Al—B alloy of the cathode electrode and the anode electrode. Arc discharge is generated, and the surface of the carbide substrate is bombarded with the Ti-Al-B alloy, and then nitrogen gas is introduced into the apparatus as a reaction gas to obtain a reaction atmosphere of 3 Pa. The bias voltage to be applied is lowered to -100V, and arc discharge is generated between the cathode electrode and the anode electrode of the Ti-Al-B alloy, thereby the carbide substrates A-1 to A-10 and B-1 As a conventional coated carbide tool, a (Ti, Al, B) N layer having a target composition and a target layer thickness shown in Tables 5 and 6 is vapor-deposited on each surface of B-6 as a hard coating layer. Conventional surface-coated 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 / SUS316 lengthwise equidistant 4 round grooved round bars,
Cutting speed: 200 m / min. ,
Cutting depth: 3.5mm,
Feed: 0.3 mm / rev. ,
Cutting time: 6 minutes
Stainless steel dry interrupted cutting test (normal cutting is 1.5 mm) under the above conditions (cutting condition A),
Work material: JIS / S15C lengthwise equal length 4 vertical grooved round bars,
Cutting speed: 280 m / min. ,
Incision: 1.5mm,
Feed: 0.5 mm / rev. ,
Cutting time: 5 minutes
Dry interrupted high feed cutting test of mild steel under normal conditions (cutting condition B) (normal feed is 0.3 mm / rev.),
Work material: JIS / SCMnH1 round bar,
Cutting speed: 250 m / min. ,
Incision: 3mm,
Feed: 0.25 mm / rev. ,
Cutting time: 8 minutes
The dry continuous high-cutting cutting test (normal cutting is 1.5 mm) of high manganese steel under the above conditions (cutting condition C) was performed, 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 substrate adhesion layer composed of the (Ti, Al) N layer having the target composition and the target layer thickness shown in Table 9 and the lower layer composed of the (Ti, Al, B) N layer, by the hard coating layer composed of a top layer made of interlayer adhesion layer and VO _M layer comprising a target layer thickness of the VN layer formed by evaporation as shown in Table 9, the present invention a surface coating of the present invention coated cemented carbide Carbide end mills (hereinafter referred to as the present invention coated end mills) 1 to 8 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. The hard coating layer consisting of the (Ti, Al, B) N layer having the target composition and target layer thickness shown in Table 10 is deposited under the same conditions as in Example 1 above. Conventional surface-coated carbide end mills (hereinafter referred to as conventional coated end mills) 1 to 8 as hard tools were produced, 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: 60 m / min. ,
Groove depth (cut): 5 mm,
Table feed: 200 mm / min,
About the dry-type high cutting groove cutting test of mild steel under the conditions of (normal groove depth is 3 mm), the present invention coated end mills 4-6 and the conventional coated end mills 4-6,
Work material-Plane dimensions: 100 mm x 250 mm, thickness: 50 mm JIS / SUS316 plate material,
Cutting speed: 65 m / min. ,
Groove depth (cut): 4 mm
Table feed: 400mm / min,
For stainless steel wet conditions (using water-soluble cutting oil), high feed groove cutting test (normal table feed is 120 mm / 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): 16 mm,
Table feed: 180mm / min,
The high-manganese steel dry-type high-groove grooving test (normal groove depth is 10 mm) was performed under the conditions described above, and the flank wear width of the outer peripheral edge of the cutting edge was 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. Under the same conditions as in Example 1 above, from the substrate adhesion layer comprising the (Ti, Al) N layer having the target composition and the target layer thickness shown in Table 11 and the (Ti, Al, B) N layer. comprising a lower layer, likewise by hard coating layer composed of a top layer made of interlayer adhesion layer and VO _M layer comprising a target layer thickness of the VN layer shown in Table 11 formed by evaporation, the present invention coated cemented carbide The present invention surface-coated 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. A hard coating layer comprising a (Ti, Al, B) N layer having the target composition and target layer thickness shown in Table 12 is formed by vapor deposition under the same conditions as in Example 1 above. Thus, conventional surface coated carbide drills (hereinafter referred to as conventional coated drills) 1 to 8 as conventional coated carbide tools were manufactured, 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: 60 m / min. ,
Feed: 0.35mm / rev,
Hole depth: 10mm,
For the stainless steel wet high feed drilling test (normal feed is 0.2 mm / rev), 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: 100 m / min. ,
Feed: 0.5mm / rev,
Hole depth: 10mm,
For the high manganese steel wet high feed drilling test under normal conditions (normal feed is 0.25 mm / rev), 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: 140 m / min. ,
Feed: 0.45mm / rev,
Hole depth: 18mm,
Each of the wet high-feed drilling machining test (normal feed is 0.25 mm / rev) of mild steel under the conditions of each of the above, and any wet high-speed drilling machining 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.

  (Ti, Al) 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 of this. Layer (base adhesion layer) and (Ti, Al, B) N layer (lower layer) composition, conventional coated tips 1-16 as conventional coated carbide tools, conventional coated end mills 1-8, and conventional coated drill 1 When the composition of the hard coating layer consisting of (Ti, Al, B) N layers of ~ 8 was measured by energy dispersive X-ray analysis using a transmission electron microscope, the composition was substantially the same as the target composition. Indicated.

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 have high viscosities such as high cutting and high feed of difficult-to-cut materials such as stainless steel, high manganese steel, and mild steel, which are particularly highly viscous and sticky. Even in cutting under the cutting conditions, the (Ti, Al, B) N layer, which is the lower layer of the hard coating layer, is tightly bonded to the surface of the carbide substrate by the (Ti, Al) N layer, which is the substrate adhesion layer. in, excellent high-temperature hardness and heat resistance, has a more excellent high-temperature strength, and by VO _M layer firmly adhered to the lower layer by VN layer as an interlayer adhesion layer, wherein the workpiece and chips Since excellent surface slipping is ensured in the meantime, chipping does not occur and excellent wear resistance is demonstrated over a long period of time, whereas the hard coating layer is a (Ti, Al, B) N layer In constructed conventional coated carbide tools In both cases, in the heavy cutting of the difficult-to-cut material, the adhesiveness and reactivity between the work material (hard-to-cut material) and the chips and the hard coating layer are further increased, and the hard coating layer is made of carbide. It is clear that since the adhesion to the substrate surface is insufficient, chipping occurs at the cutting edge and the service life is reached in a relatively short time.

  As described above, the coated carbide tool of the present invention exhibits excellent chipping resistance not only for cutting of general steel and ordinary cast iron, but particularly for heavy cutting of the above difficult-to-cut materials, and for a long time. Since it shows excellent cutting performance over time, it can sufficiently satisfactorily cope with the FA of the cutting apparatus, labor saving and energy saving of the cutting work, and further 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) having an average layer thickness of 0.5 to 2 μm and a composition formula: (Ti _1-Z Al _Z ) N (wherein Z represents 0.30 to 0.70 in atomic ratio) A substrate adhesion layer comprising a satisfactory nitride layer of Ti and Al,
(B) having an average layer thickness of 1 to 5 μm, and a composition formula: (Ti _{1− (X + Y)} Al _X B _Y ) N (however, in terms of atomic ratio, X is 0.40 to 0.70, Y Is a lower layer composed of a composite nitride layer of Ti, Al, and B (boron) satisfying 0.01 to 0.20),
(C) an interlayer adhesion layer comprising a vanadium nitride layer having an average layer thickness of 0.1 to 1.5 μm;
(D) 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 heavy cutting of difficult-to-cut materials, formed by forming a hard coating layer composed of the above (a) to (d).

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