JP2007030066A - Cutting tool made of surface coated cemented carbide having hard coated layer exhibiting excellent chipping resistance in 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 satisfying the composition formula: (Ti<SB>1-(X+y)</SB>Al<SB>X</SB>Si<SB>Y</SB>)N (wherein X is 0.30 to 0.70 and Y is 0.01 to 0.10 in an atomic ratio ); (b) 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 (c) 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 is a cutting tool made of a surface-coated cemented carbide alloy (hereinafter referred to as coated carbide) that exhibits excellent chipping resistance with a hard coating layer, especially when machining difficult-to-cut materials such as stainless steel, high manganese steel, and even mild steel. 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,
Composition formula: (Ti _{1- (X + Y)} Al _X Si _Y ) N (however, in atomic ratio, X is 0.30 to 0.70, Y is 0.01 to 0.10),
Coated carbide tool formed by physical vapor deposition of a hard coating layer composed of a composite nitride of Ti, Al, and Si [hereinafter referred to as (Ti, Al, Si) N] layer satisfying the following conditions with an average layer thickness of 1 to 15 μm And (Ti, Al, Si) 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 component, and high-temperature strength due to the Ti, Furthermore, since it has been further improved in heat resistance due to the inclusion of Si, it can also exhibit excellent cutting performance when used for continuous cutting and intermittent cutting of various general steels and ordinary cast iron. Are known.

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—Si 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, Si) N layer.
Japanese Patent No. 2793773

  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. As a result, cutting tools are affected as much as possible by the type of work material. 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. When cutting difficult-to-cut materials (work materials), the work material and chips are heated to a high temperature due to heat generated during cutting, and the viscosity further increases. Viscosity to the surface Sex and reactivity become increasingly more, as a result chipping in the cutting edge (small chipping) it increases rapidly, which is at present, leading to a relatively short time service life due.

In view of the above, the inventors of the present invention have developed the above-mentioned conventional coated super-hard tool in order to develop a coated carbide tool that exhibits excellent chipping resistance with a hard coating layer, particularly in cutting difficult-to-cut materials. As a result of conducting research with a focus on hard tools,
(A) A (Ti, Al, Si) N layer, which is a hard coating layer of the above conventional coated carbide tool, is formed with an average layer thickness of 1 to 5 μm as a lower layer, and vanadium oxide (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 (Ti, Al, Si) N-layer because it sufficiently protect, (Ti, Al, 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 (Ti, Al, 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 (Ti, Al, 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 (Ti, Al, 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 carbide substrate is provided in the center of the apparatus, and a Ti—Al—Si alloy having a predetermined composition as a cathode electrode (evaporation source) on one side with the rotating table interposed therebetween, and a cathode on the other side as well. An arc ion plating apparatus in which metal V (vanadium) is arranged as an electrode (evaporation source) is used, and a plurality of super-ions are formed along the outer periphery at a predetermined distance in the radial direction from the central axis on the rotary table of the apparatus. A hard substrate is mounted in a ring shape, 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. While the body itself rotates, basically, first, an arc discharge is generated between the cathode electrode (evaporation source) and the anode electrode of the Ti—Al—Si alloy, and the lower layer is formed on the surface of the carbide substrate. (Ti, Al, Si) 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 the Ti—Al—Si alloy is stopped, Similarly, an arc discharge is generated between the metal V as the cathode electrode (evaporation source) and the anode electrode while maintaining the atmosphere in the apparatus in a nitrogen atmosphere, so that the VN layer is 0.1 to 1.. After vapor deposition with an average layer thickness of 5 μm, the 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, it is again a cathode electrode (evaporation source). Metal V and anode By generating arc discharge between the poles, the 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. When cutting difficult-to-cut materials such as (Ti, Al, Si) N layer, the lower layer (Ti, Al, Si) N layer has excellent high-temperature hardness and heat resistance, and excellent high-temperature strength, and the VN layer as an interlayer adhesion layer by the action of VO _M layer adhesion bonding properties is secured for excellent between the lower layer by an intervening, excellent surface slipperiness between the workpiece and the chips made from the flame-cut materials is ensured 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 it can be performed over a long period of time. Excellent wear resistance To become.
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) having an average layer thickness of 1 to 5 μm and a composition formula: (Ti _{1− (X + Y)} Al _X Si _Y ) N (wherein X is 0.30 to 0.70, Y in terms of atomic ratio) Is a lower layer composed of a (Ti, Al, Si) N layer satisfying 0.01 to 0.10),
(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 composition and average layer thickness The (Ti, Al, Si) N layer constituting the lower layer has high-temperature hardness and heat resistance for the Al component, high-temperature strength for the Ti component, and further Si component Has the effect of further improving heat resistance, but when the X value indicating the proportion of Al is less than 0.30 in terms of the proportion of the total amount of Ti and Si (atomic ratio, hereinafter the same), relatively Ti The ratio becomes too high to ensure the predetermined high temperature hardness and heat resistance. As a result, the progress of wear is accelerated rapidly, while the X value indicating the Al ratio exceeds 0.70. Then, the ratio of Ti is relatively decreased, and the high temperature strength is sharply decreased. As a result, chipping or the like is likely to occur in the cutting edge portion. Therefore, the X value is set to 0.30 to 0.70. Further, the Y value indicating the proportion of Si is A If the ratio of the total amount of l and Ti is less than 0.01, the desired heat resistance improvement effect cannot be obtained. On the other hand, if the Y value exceeds 0.10, the high-temperature strength suddenly decreases. The Y value was determined to be 0.01 to 0.10.
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 since the work material remains unchanged even when it is heated at the time of cutting, the lower layer (Ti, Al, Si) N layer is formed of the work material and 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, Si) N layer constituting the hard coating layer has excellent high-temperature hardness and heat resistance, and excellent high-temperature strength, and has the same interlayer adhesion. 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 Even when cutting difficult-to-cut materials such as highly sticky stainless steel, high manganese steel, and mild steel, it exhibits excellent chipping resistance and exhibits excellent wear resistance 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 An interlayer adhesion layer and an upper layer forming metal V are arranged as a cathode electrode (evaporation source) on the other side as well as a Ti—Al—Si alloy for lower layer formation,
(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 current of 100 A is passed between the lower layer forming Ti-Al-Si alloy of the cathode electrode and the anode electrode to generate an arc discharge, and thereby the surface of the carbide substrate is made to the Ti substrate surface. -Bombard cleaning with Al-Si 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-Si 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 Table 3. , Al, Si) N layer is deposited as a lower layer of the hard coating layer,
(D) The arc discharge between the cathode electrode and the anode electrode of the Ti-Al-Si alloy for forming the lower layer described above is stopped, and the atmosphere in the apparatus is similarly maintained at a 4 Pa nitrogen atmosphere, and to the carbide substrate. The DC bias voltage of -100V was also set to -100V, and a current of 120A was passed between the metal V of the cathode electrode and the anode electrode to generate an arc discharge. Forming a layer 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 Table 3 is deposited formed as an upper layer of the hard coating layer, the present invention the surface of the present invention coated cemented carbide Coated carbide throw-away 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. The Ti-Al-Si alloy having various component compositions as the cathode electrode (evaporation source) is mounted, and the apparatus is first evacuated and kept 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—Si alloy of the cathode electrode and the anode electrode. Then, arc discharge is generated, and the surface of the carbide substrate is bombarded with the Ti—Al—Si 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 applied to the substrate is lowered to −100 V, and arc discharge is generated between the cathode electrode and the anode electrode of the Ti—Al—Si alloy, so that the carbide substrates A-1 to A-10 and B As a conventional coated carbide tool, a (Ti, Al, Si) N layer having a target composition and target layer thickness shown in Table 4 is vapor-deposited on each surface of -1 to 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: 2mm,
Feed: 0.25 mm / rev. ,
Cutting time: 8 minutes
Dry interrupted cutting test of stainless steel under the above conditions (cutting condition A),
Work material: JIS / S15C lengthwise equal length 4 vertical grooved round bars,
Cutting speed: 180 m / min. ,
Incision: 1.5mm,
Feed: 0.3 mm / rev. ,
Cutting time: 5 minutes
Dry interrupted cutting test of mild steel under the above conditions (cutting condition B),
Work material: JIS / SCMnH1 round bar,
Cutting speed: 180 m / min. ,
Cutting depth: 2mm,
Feed: 0.3 mm / rev. ,
Cutting time: 8 minutes
The dry continuous cutting test 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 5.

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 .8 μm Co powders were prepared, each of these raw material powders was blended in the composition shown in Table 6, added with wax, ball milled in acetone for 24 hours, dried under reduced pressure, and then shaped into a predetermined shape 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 Three 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 kinds of sintered rods for round bar were ground and shown in Table 6. In combination, the diameter x length of the cutting edge is 6 mm x 13 mm, 10 mm x 22 mm, and 20 mm x 45 mm, respectively, and each is made of a WC-based cemented carbide with a 4-flute square shape with a twist angle of 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, a lower layer composed of a (Ti, Al, Si) N layer having a target composition and a target layer thickness shown in Table 7 and a VN layer having a target layer thickness also shown in Table 7 by depositing form a hard coating layer composed of a top layer made of interlayer adhesion layer and VO _M layer, the present invention cover the present invention the surface coating cemented carbide end mill as carbide tools (hereinafter, referred to as the present invention coated end mill ) 1-8 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 comprising the (Ti, Al, Si) N layer having the target composition and the target layer thickness shown in Table 7 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: 55 m / min. ,
Groove depth (cut): 3 mm,
Table feed: 200 mm / min,
About the dry grooving cutting test of mild steel under the conditions of the present invention, the coated end mills 4-6 of the present invention 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: 50 m / min. ,
Groove depth (cut): 6 mm
Table feed: 150 mm / min,
For the stainless steel wet (using water-soluble cutting oil) grooving test, the present coated end mills 7 and 8 and the conventional coated end mills 7 and 8,
Work material-planar dimensions: 100 mm × 250 mm, thickness: 50 mm JIS / SCMnH1 plate material,
Cutting speed: 35 m / min. ,
Groove depth (cut): 10 mm,
Table feed: 140 mm / min,
The dry grooving test of high manganese steel under the above conditions was conducted, and in each grooving test, the flank wear width of the outer peripheral edge of the cutting edge reached 0.1 mm, which is the standard for the service life. The cutting groove length was measured. The measurement results are shown in Table 7, 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. And under the same conditions as in Example 1 above, the lower layer composed of the (Ti, Al, Si) N layer having the target composition and target layer thickness shown in Table 8 and the target layer also shown in Table 8 by depositing form a hard coating layer composed of a top layer having a thickness interlayer adhesion layer and VO _M layer made of VN layer of the present invention present invention surface coating cemented carbide drills of the coated cemented carbide (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 composed of a (Ti, Al, Si) N layer having the target composition and target layer thickness shown in Table 8 is also 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: 120 m / min. ,
Feed: 0.2mm / rev,
Hole depth: 10mm,
For the wet drilling cutting test of stainless steel under the conditions of the present invention, 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: 0.25mm / rev,
Hole depth: 20mm,
For the wet drilling cutting test of high manganese steel under the conditions of the present invention, 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: 90 m / min. ,
Feed: 0.3mm / rev,
Hole depth: 32mm,
Welding drilling test of mild steel under the above conditions, and drilling until the flank wear width of the cutting edge surface reaches 0.3mm in any wet high-speed drilling test (using water-soluble cutting oil) The number of processes was measured. The measurement results are shown in Table 8, 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 tools obtained as a result (Ti, Al, Si) ) From the composition of the N layer (lower layer) and the conventional coated chips 1-16 as a conventional coated carbide tool, the conventional coated end mills 1-8, and the (Ti, Al, Si) N layer of the conventional coated drills 1-8 The composition of the resulting hard coating layer was measured by energy dispersive X-ray analysis using a transmission electron microscope, and showed a composition substantially the same 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 8, all of the coated carbide tools of the present invention have a hard coating layer even when cutting difficult-to-cut materials such as stainless steel, high manganese steel, and mild steel, which are particularly highly viscous and sticky. The lower layer (Ti, Al, Si) N layer has excellent high-temperature hardness and heat resistance, excellent high-temperature strength, and is firmly adhered to the lower layer by the VN layer as an interlayer adhesion layer. _{The M} layer ensures excellent surface slippage between the work material and the chips, so that it exhibits excellent wear resistance over a long period of time without occurrence of chipping. In the conventional coated cemented carbide tool in which the coating layer is composed of a (Ti, Al, Si) N layer, all of the difficult-to-cut material is cut by the work material (hard-cutting material), chips and the hard coating layer. The tackiness and reactivity with It is clear that chipping occurs at the cutting edge due to this, 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 cutting of the above difficult-to-cut materials, and for a long time. Since it shows excellent cutting performance, it can fully satisfactorily cope with the FA of the cutting apparatus, labor saving and energy saving of cutting, and 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 1 to 5 μm and a composition formula: (Ti _{1− (X + Y)} Al _X Si _Y ) N (wherein X is 0.30 to 0.70, Y in terms of atomic ratio) Is a lower layer made of a composite nitride layer of Ti, Al, and Si that satisfies 0.01 to 0.10),
(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 when a difficult-to-cut material is cut by forming a hard coating layer composed of (a) to (c) above.

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