JP4747719B2 - Surface coated cermet cutting tool with excellent chipping resistance with hard coating layer in heavy cutting of difficult-to-cut materials - Google Patents

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 cermet cutting tool (hereinafter referred to as a coated cermet tool).

In general, for coated cermet tools, throwaway inserts that are detachably attached to the tip of a cutting tool for turning and planing of various steel and cast iron work materials, and drilling of the work material. Drills and miniature drills used in, etc., as well as solid type end mills used for chamfering, grooving, shouldering, etc. of the work material, and the solid type by attaching the throwaway tip detachably A slow-away end mill tool that performs a cutting process in the same manner as an end mill is known.

Further, as a coated cermet tool, on the surface of a cermet base (hereinafter simply referred to as a base) composed of a tungsten carbide (hereinafter referred to as WC) base cemented carbide or a titanium carbonitride (hereinafter referred to as TiCN) base cermet,
Composition formula: (Cr _{1- (X + Y)} Al _X B _Y ) N (wherein X is 0.40 to 0.70, Y is 0.01 to 0.20 in atomic ratio),
A hard coating layer composed of a composite nitride of Cr, Al and B (boron) satisfying the following conditions (hereinafter referred to as (Cr, Al, B) N) is physically vapor-deposited with an average layer thickness of 1 to 15 μm. A cermet tool is known, and the (Cr, Al, B) N layer, which is a hard coating layer of the coated cermet tool, has high-temperature strength due to the constituent component Cr, and high-temperature hardness and heat resistance due to the Al. In addition, since the high-temperature hardness is further improved by the inclusion of B, it exhibits excellent cutting performance when used for continuous cutting and intermittent cutting of various general steels and ordinary cast irons. It is also known.

Further, the above-mentioned coated cermet tool is charged with, for example, an arc ion plating apparatus which is one type of physical vapor deposition apparatus schematically shown in FIG. An arc discharge is generated between the anode electrode and the cathode electrode (evaporation source) on which a Cr—Al—B alloy having a predetermined composition is set, for example, under the condition of current: 90A, Nitrogen gas is introduced into the apparatus as a reaction gas to obtain a reaction atmosphere of, for example, 2 Pa. On the other hand, the above-described (Cr, Al, B) It is also known that it is produced by vapor-depositing a hard coating layer comprising an N layer.
JP 2002-169076

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 material type of the work material. There is a tendency not to have versatility, that is, a cutting tool capable of cutting as many grades as possible, but in the above-described conventional coated cermet tools, this is a general steel such as low alloy steel or carbon steel, There is no problem when used for machining of ordinary cast iron such as ductile cast iron and gray cast iron, but especially stainless steel, high manganese steel, and mild steel that have high chip viscosity and are easily welded 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 When heated to a high temperature, 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 above-mentioned (Cr, Al, B) which is a hard coating layer Since the adhesion of the N layer to the substrate surface is not sufficient, in the cutting process under heavy cutting conditions of the difficult-to-cut material, the occurrence of chipping (small chipping) in the cutting edge portion increases rapidly, and this causes relatively The current situation is that the service life is reached in a short time.

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. to develop a coated cermet tool which focuses the conventional coated cermet tool of the studies were conducted results,
(A) The (Cr, Al, B) N layer, which is a hard coating layer of the above conventional coated cermet tool, is formed with an average layer thickness of 1 to 5 μm as a lower layer, and an upper layer of vanadium oxide (hereinafter referred to as the upper layer). indicated by VO _M. However, M represents the variation of the relative proportion of oxygen to vanadium, in atomic _{ratio, VO, V 2 O 3,} V 2 O 5, and VO ₂ shows, etc.) layer also 1 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 these surfaces intersect) and the work material and the chip, and the work material and the chip with respect to the surface of the cutting edge part are secured. Adhesiveness and reactivity are significantly reduced, the lower layer Cr, Al, B) an N layer from the fully protected, (Cr, 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 (Cr, 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 (Cr, 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 (Cr, 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) Further, as described above, the adhesion of the (Cr, Al, B) N layer to the substrate surface is not sufficiently satisfactory for cutting under difficult cutting conditions under heavy cutting conditions. The composite nitride layer of Al [hereinafter referred to as (Ti, Al) N] layer is composed of a composition formula: (Ti ₁ -Z Al _Z ) N (wherein Z is 0.30 to 0.70 in atomic ratio). (Ti, Al) N layer is firmly adhered to both the substrate surface and the (Cr, Al, B) N layer when interposed with an average layer thickness of 0.5 to 2 μm. Therefore, excellent adhesion between these two is to be secured.

(D) The hard coating layer of (c) 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 mounting turntable is provided, and a Cr—Al—B alloy having a predetermined composition as a cathode electrode (evaporation source) on one side across the rotation table, and a predetermined composition as a cathode electrode (evaporation source) on the other side. And a metal V as a cathode electrode (evaporation source) at a position 90 degrees away from each of the Cr-Al-B alloy and Ti-Al alloy along the rotary table. Using the arranged arc ion plating apparatus, a plurality of substrates are mounted in a ring shape 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 in the apparatus is changed to a nitrogen atmosphere, and while rotating the rotary table and rotating the substrate itself for the purpose of uniforming the thickness of the hard coating layer to be deposited, first, the Ti An arc discharge is generated between the cathode electrode (evaporation source) of the Al alloy and the anode electrode, and a (Ti, Al) N layer as a substrate adhesion layer on the surface of the substrate is an average layer of 0.5 to 2 μm After vapor deposition with a thickness, arc discharge between the cathode electrode (evaporation source) of the Ti—Al alloy and the anode electrode was stopped, and the Cr—Al— An arc discharge is generated between the cathode electrode (evaporation source) and the anode electrode of the B alloy, and a (Cr, Al, B) N layer is deposited as an underlying layer with an average layer thickness of 1 to 5 μm, and then the Cr -Al-B composite The arc discharge between the cathode electrode (evaporation source) and the anode electrode is stopped, and the atmosphere in the apparatus is maintained in the nitrogen atmosphere, and the cathode V (evaporation source) is placed between the metal V and the anode electrode. After arc discharge is generated and a VN layer is deposited as an interlayer adhesion layer with an average layer thickness of 0.1 to 1.5 μm, arc discharge between the metal V and the anode electrode is stopped, and the inside of the deposition apparatus When the atmosphere was switched to an oxygen atmosphere, an arc discharge was generated again between the metal V as the cathode electrode (evaporation source) and the anode electrode, and an average of 1 to 5 μm was formed as the upper layer on the VN layer. it can be formed by depositing VO _M layer in the layer thickness.

(E) A coated cermet tool formed by vapor-depositing a hard coating layer composed of the above-mentioned substrate adhesion layer, lower layer, interlayer adhesion layer, and upper layer is particularly a stainless steel or high manganese steel with high viscosity and adhesion. In addition, even when cutting difficult-to-cut materials such as mild steel under heavy cutting conditions such as high cutting with high load and high feed, the lower layer is firmly bonded to the substrate surface through the substrate adhesion layer. A certain (Cr, Al, B) N layer has excellent high-temperature hardness and heat resistance, excellent high-temperature strength, and excellent adhesion bonding between the lower layer due to the intervening VN layer as an interlayer adhesion layer by the action of VO _M layers gender is ensured, excellent surface slipperiness between the flame cut materials and chips is ensured, tack and reactivity to the cutting edge surface of the flame-cut materials and chips Cutting in a significantly reduced state Therefore, no chipping occurs at the cutting edge, 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 substrate, using an arc ion plating apparatus ,
(A) having an average layer thickness of 0.5 to 2 μm formed by vapor deposition using a Ti—Al alloy having a predetermined composition as a cathode electrode ;
Composition formula: (Ti ₁ -Z Al _Z ) N (however, in atomic ratio, Z represents 0.30 to 0.70),
A substrate adhesion layer comprising a (Ti, Al) N layer satisfying
(B) an average layer thickness of 1 to 5 μm formed by vapor deposition using a Cr—Al—B alloy having a predetermined composition as a cathode electrode ; and
Composition formula: (Cr _{1- (X + Y)} Al _X B _Y ) N (wherein, X is 0.40 to 0.70, Y is 0.01 to 0.20 in atomic ratio),
A lower layer comprising a (Cr, Al, B) N layer satisfying
(C) an interlayer adhesion layer comprising a VN layer having an average layer thickness of 0.1 to 1.5 μm, formed by vapor deposition using metal V as a cathode electrode ;
(D) also deposited formed of a metal V as a cathode electrode, 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 cermet tool that forms a hard coating layer constituted of (a) to (d) above and exhibits excellent chipping resistance in heavy 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 cermet tool of the present invention are limited as described above will be described.

(A) Composition and average layer thickness of substrate adhesion layer In the (Cr, 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. Although it has an action that contributes to the surface, in particular, it is a component that lowers the adhesion to the substrate surface. Therefore, the substrate adhesion layer is composed of a (Ti, Al) N layer, and the action of Ti, which is a component thereof, causes the substrate surface. It is intended to ensure strong adhesion to both the lower layer and the lower layer, while containing the same Al component improves the high-temperature hardness and heat resistance of the layer itself as in the lower layer, and is hard Although it contributes to the improvement of the wear resistance of the coating layer, when the Z value indicating the proportion of Al is less than 0.30 in terms of the proportion of the total amount with Ti (atomic ratio, the same shall apply hereinafter), a predetermined high-temperature hardness is achieved. And heat resistance cannot be ensured This causes a decrease in wear resistance. On the other hand, if the Z value indicating the Al ratio exceeds 0.70, the Ti ratio is relatively less than 0.30, which is desired between the substrate surface and the lower layer. Since the excellent adhesion cannot be ensured, the Z value is determined to be 0.30 to 0.70.

  On the other hand, if the average layer thickness is less than 0.5 μm, the desired excellent adhesion between the substrate surface and the lower layer cannot be ensured. On the other hand, if the average layer thickness exceeds 2 μm, the above-mentioned high viscosity is difficult. Since the heavy cutting of the cutting 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) Lower layer composition and average layer thickness (Cr, Al, B) The Al component in the lower layer is improved in high-temperature hardness and heat resistance in the N layer, and the Cr component is improved in high-temperature strength. 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 terms of the proportion of the total amount of Cr and B (atomic ratio, the same shall apply hereinafter), Cr As a result, the predetermined high temperature hardness and heat resistance cannot be ensured, and as a result, the progress of wear is accelerated rapidly, while the X value indicating the Al ratio is 0.70. If exceeded, the proportion of Cr becomes relatively small and the high-temperature strength rapidly decreases. As a result, chipping or the like is likely to occur in the cutting edge portion, so the X value is 0.40 to 0.70. Furthermore, Y value indicating the ratio of B is Cr and A If the ratio to the total amount of l is less than 0.01, the desired high-temperature hardness improvement effect cannot be obtained. On the other hand, if the Y value exceeds 0.20, the high-temperature strength suddenly decreases. The Y value was determined to be 0.01-0.20.

  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. Since the chipping is likely to occur at the cutting edge in the cutting of the cutting material, the average layer thickness is set to 1 to 5 μm.

(C) Average layer thickness of interlayer adhesion layer When 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.

(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 is maintained without change even when the workpiece is heated at the time of cutting. Therefore, the (Cr, Al, B) N layer, which is the lower layer, is cut into the workpiece heated and cut at the high temperature. Protects from powder and exerts an effect 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 operation, while the average layer thickness exceeds 5 μm. If it is too much, chipping is likely to occur, so the average layer thickness was set to 1 to 5 μm.

In the coated cermet tool of the present invention, the lower (Cr, Al, B) N layer constituting the hard coating layer is firmly bonded to the substrate surface by the action of the (Ti, Al) N layer which is the substrate adhesion layer. in state, excellent high-temperature hardness and heat resistance, further excellent have 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 workpiece (flame Excellent slipperiness between the cutting material and the cutting chips is ensured. Therefore, heavy cutting with high load on difficult-to-cut materials such as highly viscous and sticky stainless steel, high manganese steel, and mild steel. Even during processing, it exhibits excellent chipping resistance and exhibits excellent wear resistance over a long period of time.

Next, the coated cermet tool of the present invention will be specifically described with reference to examples.

As raw material powders, WC powder, TiC powder, ZrC powder, VC powder, TaC powder, NbC powder, Cr ₃ C ₂ powder, TiN powder, TaN powder, all having a predetermined average particle diameter in the range of 1 to 3 μm, And Co powder, these raw material powders are blended in the composition shown in Table 1, wet mixed for 72 hours by a ball mill, dried, and then pressed into a green compact at a pressure of 100 MPa. The body was sintered in a vacuum of 6 Pa at a temperature of 1400 ° C. for 1 hour. After sintering, the cutting edge portion was subjected to a honing process of R: 0.03 to have a chip shape of ISO standard / CNMG120408. Then, bases A-1 to A-10 made of WC-based cemented carbide were formed.

In addition, as raw material powders, TiCN (mass ratio, TiC / TiN = 50/50) powder, Mo ₂ C powder, ZrC powder, NbC powder each having a predetermined average particle size in the range of 0.5 to 2 μm. , TaC powder, WC powder, Co powder, and Ni powder are prepared, these raw material powders are blended in the blending composition shown in Table 2, wet mixed by a ball mill for 24 hours, dried, and then pressed at a pressure of 100 MPa. The powder compact is press-molded, and this green compact is sintered in a nitrogen atmosphere of 2 kPa at a temperature of 1500 ° C. for 1 hour. After sintering, the cutting edge portion is subjected to a honing process of R: 0.03. Then, bases B-1 to B-6 made of TiCN-based cermet having a chip shape of ISO standard / CNMG120408 were formed.

(A) Next, each of the substrates A-1 to A-10 and B-1 to B-6 is ultrasonically cleaned in acetone and dried, and then the arc ion plating apparatus shown in FIG. A lower layer having a predetermined composition as a cathode electrode (evaporation source) on one side of the rotary table is mounted along the outer peripheral portion at a predetermined distance in the radial direction from the central axis on the inner rotary table. A Cr—Al—B alloy for forming, 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 other,
(B) First, the inside of the apparatus is evacuated and kept at a vacuum of 0.1 Pa or less, and the inside of the apparatus is heated to 500 ° C. with a heater, and then the direct current of −1000 V is applied to the base that rotates while rotating on the rotary table. A bias voltage is applied, and an arc discharge is generated by flowing a current of 100 A between the Ti—Al alloy for forming the substrate adhesion layer of the cathode electrode and the anode electrode, whereby the substrate surface is bombarded by the Ti—Al alloy. Wash and
(C) Nitrogen gas is introduced as a reaction gas into the apparatus to form a 4 Pa reaction atmosphere, a DC bias voltage of −100 V is applied to the substrate rotating while rotating on the rotary table, and the cathode electrode An arc discharge is generated by flowing a current of 120 A between the Ti—Al alloy and the anode electrode, so that (Ti, Al) N having a target composition and a target layer thickness shown in Tables 3 and 4 are formed on the surface of the substrate. The layer is deposited 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 the DC bias voltage to the substrate In the same manner, the current of 120 A was passed between the Cr—Al—B alloy of the cathode electrode and the anode electrode while keeping the voltage at −100 V to generate an arc discharge. (Cr, Al, B) N layer having the target composition and target layer thickness shown in FIG. 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 Cr—Al—B alloy for forming the lower layer is stopped, the atmosphere in the apparatus is maintained in a nitrogen atmosphere of 4 Pa, and direct current to the substrate Under the condition that the bias voltage is also -100 V, a current of 120 A is caused to flow 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,
(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 invention as the present invention coated cermet tool Surface-coated cermet throwaway tips (hereinafter referred to as the present invention-coated tips) 1 to 16 were produced.

For comparison purposes, these substrates A-1 to A-10 and B-1 to B-6 were ultrasonically cleaned in acetone and dried, respectively, and the arc ion plating apparatus shown in FIG. A Cr—Al—B alloy having various component compositions is mounted as a cathode electrode (evaporation source). First, the apparatus is evacuated and kept at a vacuum of 0.1 Pa or less with a heater. After heating the inside of the apparatus to 500 ° C., a DC bias voltage of −1000 V is applied to the substrate, and a current of 100 A is passed between the Cr—Al—B alloy of the cathode electrode and the anode electrode to cause arc discharge. Then, the substrate surface is bombarded with the Cr—Al—B alloy, and then nitrogen gas is introduced into the apparatus as a reaction gas to form a reaction atmosphere of 3 Pa, and a via applied to the substrate. The voltage is lowered to -100 V to generate an arc discharge between the cathode electrode and the anode electrode of the Cr-Al-B alloy, and thus the bases A-1 to A-10 and B-1 to B-6 A conventional surface-coated cermet as a conventional coated cermet tool is formed on each surface by vapor-depositing a (Cr, Al, B) N layer having the target composition and thickness shown in Tables 5 and 6 as a hard coating layer. Slow away chips (hereinafter referred to as conventional coated chips) 1 to 16 were produced.

Next, in the state where each of the above-mentioned various coated chips is screwed to the tip of the tool steel tool with a fixing jig, the present coated chips 1-16 and the conventional coated chips 1-16,
Work material: JIS · SCMnH1 lengthwise equidistant four round grooved round bars,
Cutting speed: 250 m / min. ,
Incision: 3mm,
Feed: 0.3 mm / rev. ,
Cutting time: 5 minutes
Of high manganese steel under the above conditions (cutting condition A), a dry intermittent high cutting test (normal cutting is 1.5 mm)
Work material: JIS / SUS316 round bar,
Cutting speed: 220 m / min. ,
Incision: 2.5mm,
Feed: 0.25 mm / rev. ,
Cutting time: 7 minutes
Stainless steel dry continuous high-cut cutting test under normal conditions (cutting condition B) (normal cutting is 1.5 mm),
Work material: JIS / S15C lengthwise equal length 4 vertical grooved round bars,
Cutting speed: 260 m / min. ,
Cutting depth: 3.5mm,
Feed: 0.45 mm / rev. ,
Cutting time: 8 minutes
Was performed in a dry interrupted high feed cutting test (normal feed is 0.3 mm / rev.), 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 size of 5.5 μm, 0.8 μm fine WC powder, 1.3 μm TaC powder, 1.2 μm NbC powder, 1.2 μm ZrC 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 and ball mill mix in acetone for 24 hours, dry under reduced pressure, and then 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, the diameter is 8 m, 13 mm, and 26 mm of three types of round bar sintered bodies for forming a substrate are formed, and further, the above three types of round bar sintered bodies are ground and combined with the combinations shown in Table 8 by cutting. WC-base cemented carbide base body (end mill) having a 4-blade square shape with dimensions of 6 mm × 13 mm, 10 mm × 22 mm, and 20 mm × 45 mm, and a twist angle of 30 degrees. C-1 to C-8 were produced respectively.

Then, the surfaces of these 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. 1 under the same conditions as those in Table 1, a substrate adhesion layer composed of a (Ti, Al) N layer having a target composition and a target layer thickness shown in Table 9, and a lower layer composed of a (Cr, Al, B) N layer. the present invention surface coating cermet end mill of target layer thicknesses hard layer composed of a top layer made of interlayer adhesion layer and VO _M layer made of VN layer by depositing formed, as the present invention coated cermet tool shown in 1 to 8 (hereinafter referred to as the present invention coated end mill) were produced.

For comparison purposes, the surfaces of the substrates (end mills) C-1 to C-8 were ultrasonically cleaned in acetone and dried, and then loaded into the arc ion plating apparatus shown in FIG. As a conventional coated cermet tool, a hard coating layer composed of a (Cr, Al, B) N layer having the target composition and the target layer thickness shown in Table 10 is vapor-deposited under the same conditions as in Example 1. The conventional surface-coated cermet end mills (hereinafter referred to as conventional coated end mills) 1 to 8 were produced.

Next, of the present invention coated end mills 1 to 8 and the conventional coated end mills 1 to 8, the present coated end mills 1 to 3 and the conventional coated end mills 1 to 3 are as follows:
Work material-Plane dimensions: 100 mm x 250 mm, thickness: 50 mm JIS / SUS316 plate material,
Cutting speed: 50 m / min. ,
Groove depth (cut): 4.5 mm,
Table feed: 180mm / min,
For the stainless steel dry type high-grooving groove cutting test (normal groove depth is 3 mm), the coated end mills 4 to 6 of the present invention and the conventional coated end mills 4 to 6
Work material-planar dimensions: 100 mm x 250 mm, thickness: 50 mm JIS / S15C plate,
Cutting speed: 65 m / min. ,
Groove depth (cut): 4 mm
Table feed: 350 mm / min,
With respect to the dry high feed groove cutting test of mild steel under the conditions of (normal table feed is 120 mm / min), the present coated end mills 7 and 8 and the conventional coated end mills 7 and 8,
Work material-planar dimensions: 100 mm × 250 mm, thickness: 50 mm JIS / SCMnH1 plate material,
Cutting speed: 60 m / min. ,
Groove depth (cut): 15 mm,
Table feed: 220 mm / 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 bases C-1 to C-3), 13 mm (for forming bases C-4 to C-6), and 26 mm (for forming bases C-7 and C-8). 3 types of round bar sintered bodies were used, and from these three types of round bar sintered bodies, the diameter x length of the groove forming portion was 4 mm x 13 mm (bases D-1 to D) by grinding. -3), 8 mm × 22 mm (bases D-4 to D-6), and 16 mm × 45 mm (bases D-7, D-8), and each has a two-blade shape with a twist angle of 30 degrees. Substrates (drills) D-1 to D-8 made of WC-base cemented carbide were produced.

Next, the cutting edges of these substrates (drills) D-1 to D-8 are subjected to honing, ultrasonically cleaned in acetone, and dried, and then mounted on the arc ion plating apparatus shown in FIG. Then, under the same conditions as in Example 1, the substrate adhesion layer composed of the (Ti, Al) N layer and the lower layer composed of the (Cr, Al, B) N layer having the target composition and the target layer thickness shown in Table 11 layer and, likewise by a hard 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 as the invention coated cermet tool Invention surface-coated cermet drills (hereinafter referred to as the present invention-coated drills) 1 to 8 were produced, respectively.

For comparison purposes, the surfaces of the substrates (drills) D-1 to D-8 are subjected to honing, ultrasonically cleaned in acetone, and dried, and the arc ion plate shown in FIG. A hard coating layer composed of a (Cr, Al, B) N layer having the target composition and target layer thickness shown in Table 12 under the same conditions as in Example 1 above. Thus, conventional surface-coated cermet drills (hereinafter referred to as conventional coated drills) 1 to 8 as conventional coated cermet 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: 55 m / min. ,
Feed: 0.4mm / rev,
Hole depth: 8mm,
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: 90 m / min. ,
Feed: 0.4mm / rev,
Hole depth: 14mm,
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: 125 m / min. ,
Feed: 0.5mm / rev,
Hole depth: 23mm,
Wet and high-drilling drilling test for mild steel under normal conditions (normal feed is 0.25 mm / rev), and any wet drilling test (with 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.

(Ti, Al) N layer 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 cermet tool obtained as a result (Substrate adhesion layer) and (Cr, Al, B) N layer (lower layer) composition, conventional coated tips 1-16 as conventional coated cermet tools, conventional coated end mills 1-8, and conventional coated drills 1-8 The composition of the hard coating layer composed of the (Cr, Al, B) N layer was measured by energy dispersive X-ray analysis using a transmission electron microscope, and showed substantially the same composition as the target composition. .

Moreover, as measured by the present invention coating VO _M layer constituting the hard layer of the cermet tools energy dispersive X-ray analysis of the composition of (upper layer) likewise with a transmission electron microscope, a composition formula, the VO A mixed structure containing V ₂ O ₃ , V ₂ O ₅ , VO _{2 and the} like as a main component is shown.

  Moreover, when the average layer thickness of the constituent layers of the hard coating layer was measured by a cross-section using a scanning electron microscope, all showed an average value (average value of five locations) substantially the same as the target layer thickness.

From the results shown in Tables 3 to 12, all of the coated cermet tools of the present invention are particularly heavy cutting such as high cutting and high feed of difficult-to-cut materials such as stainless steel and high manganese steel having high viscosity and adhesion, and mild steel. Even in cutting under conditions, the (Cr, Al, B) N layer, which is the lower layer of the hard coating layer, is excellent in a state where the (Ti, Al) N layer, which is the substrate adhesion layer, is firmly adhered to the substrate surface. a high-temperature hardness and heat resistance, the more excellent high-temperature strength, and by VO _M layer firmly adhered to the lower layer by VN layer as an interlayer adhesion layer, excellent between the workpiece and chips Since the surface slipperiness is ensured, chipping does not occur and excellent wear resistance is exhibited over a long period of time, whereas the hard coating layer is composed of a (Cr, Al, B) N layer. Conventional coated cermet tool In the above, 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 base of the hard coating layer It is clear that since the adhesion to the 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 cermet tool of the present invention exhibits excellent chipping resistance not only for cutting of general steel and ordinary cast iron, but also for heavy 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 cermet 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 cermet substrate composed of tungsten carbide based cemented carbide or titanium carbonitride based cermet, with an arc ion plating device ,
(A) having an average layer thickness of 0.5 to 2 μm formed by vapor deposition using a Ti—Al alloy having a predetermined composition as a cathode electrode ;
Composition formula: (Ti ₁ -Z Al _Z ) N (however, in atomic ratio, Z represents 0.30 to 0.70),
A substrate adhesion layer comprising a composite nitride layer of Ti and Al satisfying
(B) an average layer thickness of 1 to 5 μm formed by vapor deposition using a Cr—Al—B alloy having a predetermined composition as a cathode electrode ; and
Composition formula: (Cr _{1- (X + Y)} Al _X B _Y ) N (wherein, X is 0.40 to 0.70, Y is 0.01 to 0.20 in atomic ratio),
A lower layer comprising a composite nitride layer of Cr, Al and B (boron) satisfying
(C) an interlayer adhesion layer comprising a vanadium nitride layer having an average layer thickness of 0.1 to 1.5 μm, formed by vapor deposition using metal vanadium as a cathode electrode ;
(D) an upper layer comprising a vanadium oxide layer having an average layer thickness of 1 to 5 μm, which is also deposited using metal vanadium as the cathode electrode ;
A surface-coated cermet 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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