JP4697659B2 - Surface coated cutting tool with excellent wear resistance with hard coating layer in high speed cutting of heat resistant alloy - Google Patents

Description

  This invention has excellent high-temperature oxidation resistance with a hard coating layer. Therefore, especially when heat-resistant steel, Co alloy, and heat-resistant alloys such as Ni alloy are cut under high-speed cutting conditions with high heat generation. In addition, the progress of wear of the hard coating layer is remarkably suppressed, and as a result, the surface of the cemented carbide substrate made of tungsten carbide-based cemented carbide or titanium carbonitride-based cermet that exhibits excellent wear resistance over a long period of time. Alternatively, the present invention relates to a surface-coated cutting tool in which a hard coating layer is formed on the surface of a high-speed tool steel base.

  In general, surface-coated cutting tools include a throw-away tip that is detachably attached to the tip of a cutting tool for turning and planing of various steels and cast irons, 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.

Also, as one of the surface-coated cutting tools, for example, on the surface of a cemented carbide substrate composed of tungsten carbide (hereinafter referred to as WC) -based cemented carbide or titanium carbonitride (hereinafter referred to as TiCN) -based cermet, Having a single phase structure, and
_{Formula: [Ti 1- (E + F} ) Al E Y F] N ( provided that an atomic ratio, E is 0.50 to .65, F denotes the 0.01-0.10)
A hard coating layer composed of a composite nitride of Ti, Al, and Y (yttrium) [hereinafter referred to as (Ti, Al, Y) N] layer satisfying the following conditions is vapor-deposited with an average layer thickness of 2 to 6 μm. Carbide tools are known, and the (Ti, Al, Y) N layer has improved high-temperature hardness and heat resistance by Al as a constituent component, high-temperature strength by Ti, and high-temperature oxidation resistance by Y. It is also known to have properties.

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 the cathode electrode (evaporation source) on which a Ti—Al—Y 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, Y) N layer.
JP-A-8-199338

  In recent years, the performance of cutting devices has been dramatically improved, while on the other hand, there is a strong demand for labor saving, energy saving, and cost reduction for cutting, and with this, cutting tends to be faster. In coated carbide tools, when used for cutting carbon steel, low alloy steel, and ordinary cast iron under high-speed cutting conditions, there is no problem with normal cutting performance. When cutting heat-resistant alloys such as steel, Co alloy, and Ni alloy under high-speed cutting conditions, heat generation during cutting is significant and the hard coating layer (Ti, Al, Y) ) In the N layer, wear progresses rapidly due to insufficient high-temperature oxidation resistance, and as a result, the wear life is reached in a relatively short time.

In view of the above, the inventors of the present invention have a surface-coated cutting tool in which the hard coating layer takes a normal wear form especially in high-speed cutting of the above heat-resistant alloy and exhibits excellent wear resistance over a long period of time. As a result of conducting research by paying attention to the (Ti, Al, Y) N layer that constitutes the hard coating layer of the above conventional coated carbide tool,
(A) In the (Ti, Al, Y) N layer constituting the hard coating layer, the higher the content ratio of the Y component, the higher the high-temperature oxidation resistance, but the conventional (Ti, Al , Y) When the Y content is about 1 to 10 atomic% in the N layer, it is possible to provide excellent high-temperature oxidation resistance that sufficiently suppresses the progress of wear in high-speed cutting with high heat generation of the heat-resistant alloy. In order to ensure excellent high-temperature oxidation resistance sufficient to sufficiently suppress the progress of wear by high-speed cutting of the heat-resistant alloy, 15-30 atomic% far exceeding the above-mentioned 1-10 atomic%. On the other hand, the (Ti, Al, Y) N layer containing 15 to 30 atomic% of the Y component is severely brittle, and for this reason, a predetermined amount of the Ti component that contributes to the improvement of the high-temperature strength. Is essential, but in this way a large amount When a component and a predetermined amount of Ti component are contained, there is very little room for the Al component, and as a result, the high temperature hardness and heat resistance are extremely low. What can not be.

(B) In the (Ti, Al, Y) N layer of the above (a), the Y content ratio was made extremely high, while the Al content ratio was lowered by increasing the Y component content ratio (Ti, Al, Y). ) N layer (hereinafter referred to as thin layer A), Y content is lower than the thin layer A, Al content is relatively high, predetermined relatively high high temperature hardness and heat resistance (Ti, Al, Y) N layers (hereinafter referred to as “thin layers B”) provided with the above-mentioned layers are alternately laminated in a state where each layer has an average layer thickness of 5 to 20 nm (nanometers). The (Ti, Al, Y) N layer having the structure does not impair the excellent high-temperature oxidation resistance of the thin layer A having a high Y content, and the thin layer B having a relatively high Al content ratio allows the high temperature hard And high heat resistance to compensate for high temperature oxidation resistance and relative The alternate stacked structure which holds a high high-temperature hardness and heat resistance (Ti, Al, Y) N layer and made possible.

Here, the composition formulas of the thin layer A and the thin layer B are as follows.

Composition formula of the thin layer A: “Ti _{1− (A + B)} Al _A Y _B ] N (where A represents 0.15 to 0.30 and B represents 0.15 to 0.30 in atomic ratio)
Composition formula of thin layer B: [Ti _{1- (C + D)} Al _C Y _D ] N (however, in atomic ratio, C is 0.50 to 0.65, D is 0.01 to 0.10)

(C) The (Ti, Al, Y) N layer having the alternate layered structure of the thin layer A and the thin layer B in (b) has excellent high temperature oxidation resistance required for high speed cutting of a heat resistant alloy. Although it does not yet have a sufficiently high temperature hardness and heat resistance, it is provided as an upper layer of the hard coating layer, while the lower layer does not have sufficient high temperature oxidation resistance, (Ti, Al, Y) N layer having a composition corresponding to the above-described conventional hard coating layer having a high Al component content and excellent high-temperature hardness and heat resistance,
Composition formula: [Ti _{1− (E + F)} Al _E Y _F ] N (wherein E is 0.50 to 0.60 and F is 0.01 to 0.10 in atomic ratio), (Ti, Al, Y) N layer of single phase structure,
In this structure, the hard coating layer has a combination of high temperature hardness, heat resistance, and high temperature strength, in addition to excellent high temperature oxidation resistance. The surface-coated cutting tool formed by vapor-depositing has excellent wear resistance because the progress of wear of the hard coating layer is remarkably suppressed even in high-speed cutting with high heat generation of the above heat-resistant alloy. It will come out for a long time.
The research results shown in (a) to (c) above were obtained.

This invention was made based on the above research results,

On the surface of a cemented carbide substrate made of tungsten carbide-based cemented carbide or titanium carbonitride-based cermet, or on the surface of a high-speed tool steel substrate,
(A) Both are composed of an upper layer and a lower layer made of (Ti, Al, Y) N, the upper layer has a thickness of 0.5 to 1.5 μm, and the lower layer has a thickness of 2 to 6 μm. ,
(B) Each of the upper layers has an alternately laminated structure of thin layers A and B having a layer thickness of 5 to 20 nm (nanometer),
The thin layer A is
Composition formula: [Ti _{1− (A + B)} Al _A Y _B ] N (wherein A is 0.15 to 0.30 and B is 0.15 to 0.30 in terms of atomic ratio) (Ti , Al, Y) N layer,
The thin layer B is
Composition formula: [Ti _{1− (C + D)} Al _C Y _D ] N (wherein C is 0.50 to 0.65 and D is 0.01 to 0.10 in atomic ratio) (Ti , Al, Y) N layer,
(C) the lower layer has a single phase structure;
Composition formula: [Ti _{1− (E + F)} Al _E Y _F ] N (wherein E is 0.50 to 0.65 and F is 0.01 to 0.10 in atomic ratio) (Ti , Al, Y) N layer,
It is characterized by a surface-coated cutting tool that exhibits excellent wear resistance in high-speed cutting of a heat-resistant alloy formed by vapor-depositing a hard coating layer made of

Next, the reason why the numerical values of the hard coating layer of the surface-coated cutting tool of the present invention are limited as described above will be described.
(A) Composition formula and layer thickness of the lower layer As described above, the Al component in the (Ti, Al, Y) N layer constituting the hard coating layer improves the high temperature hardness and heat resistance, while the Ti component Has the effect of improving the high-temperature strength and further the high-temperature oxidation resistance of the Y component. In the lower layer, the Al component content is generally increased to provide high-temperature hardness and heat resistance. If the E value indicating the content ratio is less than 0.50 in terms of the total amount of Ti and Y (atomic ratio, the same shall apply hereinafter), excellent high-temperature hardness required for high-speed cutting of heat-resistant alloys with extremely high heat generation In addition, heat resistance cannot be ensured, causing wear progress promotion. On the other hand, if the E value indicating the Al ratio exceeds 0.65, the high-temperature strength decreases rapidly, resulting in chipping (small chipping). Etc. are likely to occur. It was set to 0.50 to 0.65.
Further, if the F value indicating the proportion of Y is the proportion of the total amount of Ti and Al, and less than 0.01, a predetermined minimum high temperature oxidation resistance cannot be ensured, while the F value is 0. If it exceeds .10, the above-mentioned excellent characteristics of the lower layer, that is, high temperature hardness and heat resistance, and high temperature strength suddenly decrease, so the F value is set to 0.01 to 0.10. It was.
Furthermore, if the layer thickness is less than 2 μm, the excellent high-temperature hardness and heat resistance cannot be imparted to the hard coating layer over a long period of time, resulting in a short tool life, while if the layer thickness exceeds 6 μm Since the chipping is likely to occur, the layer thickness is set to 2 to 6 μm.

(B) Composition formula of upper layer thin layer A As described above, the Y component in (Ti, Al, Y) N of the upper layer thin layer A is made as high as possible to further enhance high-temperature oxidation resistance. It is included for the purpose of suppressing the progress of wear in high-speed cutting of a heat-resistant alloy with high heat generation, and therefore, if the B value is less than 0.15, the desired excellent high-temperature oxidation resistance should be ensured. On the other hand, when the B value exceeds 0.30, the content ratio of the Ti component is relatively decreased, and the high-temperature strength that the layer itself should have can be secured, and the layer is practically used. Therefore, the B value was set to 0.15 to 0.30.
Further, the A value indicating the proportion of Al is the proportion of the total amount of Ti and Y, and if it is less than 0.15, the minimum high-temperature hardness and heat resistance cannot be ensured, causing wear acceleration, On the other hand, if the A value exceeds 0.30, the high-temperature strength suddenly decreases and causes chipping, so the A value was set to 0.15 to 0.30.

(C) Composition formula of thin layer B of the upper layer In the thin layer B of the upper layer, the content ratio of the Y component is relatively lower than that of the thin layer A, and the content ratio of the Al component is relatively By keeping the thin layer A high, the thin layer A has insufficient high temperature hardness and heat resistance, reinforces the high temperature hardness and insufficient heat resistance of the adjacent thin layer A, and thus the thin layer A has excellent properties. The upper layer having the relatively excellent high temperature hardness and heat resistance of the thin layer B is formed without impairing the high temperature oxidation resistance.

If the C value indicating the Al content in the composition formula of the thin layer B is less than 0.50, the predetermined relatively excellent high-temperature hardness and heat resistance cannot be ensured, and the progress of wear is promoted. On the other hand, when the C value exceeds 0.65, the high temperature strength of the entire upper layer is inevitably lowered, and this causes chipping. Therefore, the C value is set to 0.50 to 0.65.
Further, if the D value indicating the proportion of Y is the proportion of the total amount of Ti and Al, and less than 0.01, a decrease in the high-temperature oxidation resistance of the entire upper layer is inevitable, while the D value is 0.10. Since the high-temperature strength of the entire upper layer suddenly decreases, the D value is set to 0.01 to 0.10.

(D) Layer thicknesses of upper layer thin layer A and layer B If each layer thickness is less than 5 nm, it is difficult to form each thin layer clearly with the above composition. Excellent high-temperature oxidation resistance, and a predetermined relatively high high-temperature hardness and heat resistance cannot be ensured. Further, when the thickness of each layer exceeds 20 nm, the disadvantage of each thin layer, that is, the thin layer A If there is insufficient high-temperature hardness and heat resistance, if it is thin layer B, insufficient high-temperature oxidation resistance will appear locally in the layer, which is likely to cause chipping and promote wear progress. Each layer thickness was determined to be 5 to 20 nm.

That is, the thin layer B is provided to compensate for insufficient properties among the properties of the thin layer A, but the average layer thickness of each of the thin layers A and B is in the range of 5 to 20 nm. If it is in the upper layer, the upper layer composed of the alternately laminated structure of the thin layer A and the thin layer B has excellent high temperature oxidation resistance, and as if it had predetermined high temperature hardness and heat resistance without impairing this. It acts as if it is a single layer. However, if the average layer thickness of each of the thin layer A and the thin layer B exceeds 20 nm, the high temperature hardness of the thin layer A, insufficient heat resistance, or the thin layer B Insufficient thermal conductivity appears locally in the layer, and the upper layer as a whole cannot exhibit good characteristics as a single layer, so the average layer thickness of each of the thin layer A and the thin layer B Was determined to be 5 to 20 nm.
By forming on the lower layer surface an upper layer having an alternate layer structure in which the average layer thickness of the thin layer A and the thin layer B is in the range of 5 to 20 nm, excellent high temperature oxidation resistance, high temperature hardness, heat resistance Thus, a hard coating layer having both properties and high temperature strength can be obtained.

(E) Layer thickness of the upper layer When the layer thickness is less than 0.5 μm, the excellent high temperature oxidation resistance and the predetermined high temperature hardness and heat resistance cannot be imparted to the hard coating layer over a long period of time. On the other hand, if the layer thickness exceeds 1.5 μm, chipping tends to occur. Therefore, the layer thickness is set to 0.5 to 1.5 μm.

  In the surface-coated cutting tool of the present invention, the hard coating layer is composed of a (Ti, Al, Y) N layer. The upper layer of the hard coating layer has a predetermined structure by forming an alternating layer structure of thin layers A and thin layers B. In addition to maintaining the high temperature hardness and heat resistance of the steel, it has excellent high temperature oxidation resistance, and the lower layer of the single phase structure has relatively high temperature hardness and heat resistance. Even in high-speed cutting with high heat generation of heat-resistant alloys such as Co alloys and Ni alloys, the progress of wear of the hard coating layer is suppressed, and excellent wear resistance is exhibited over a long period of time.

  Next, the surface-coated cutting 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.

In addition, as raw material powders, all are TiCN (weight ratio TiC / TiN = 50/50) powder, Mo ₂ C powder, ZrC powder, NbC powder, TaC powder, WC powder having an average particle diameter of 0.5 to 2 μm. Co powder and Ni powder are prepared, and 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 into a compact at a pressure of 100 MPa. The green compact was sintered in a nitrogen atmosphere of 2 kPa at a temperature of 1500 ° C. for 1 hour, and after sintering, the cutting edge portion was subjected to a honing process of R: 0.03 to obtain ISO standard / CNMG120408. The carbide substrates B-1 to B-6 made of TiCN base cermet having the following chip shape 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 peripheral portion at a predetermined distance in the radial direction from the central axis on the rotary table in the coating apparatus, and used as a cathode electrode (evaporation source) on one side with the target compositions shown in Tables 3 and 4, respectively. As the upper layer Ti-Al-Y alloy with the corresponding component composition and the cathode electrode (evaporation source) on the other side, the component compositions corresponding to the target compositions shown in Tables 3 and 4 are also used. The upper layer thin layer B and the lower layer forming Ti-Al-Y alloy are disposed opposite to each other with the rotary table interposed therebetween,
(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 applied between the thin layer B and the Ti-Al-Y alloy for forming the lower layer and the anode electrode to generate an arc discharge. Bombarded with Ti-Al-Y alloy,
(C) Introducing nitrogen gas as a reaction gas into the apparatus to make a reaction atmosphere of 3 Pa, applying a DC bias voltage of −100 V to a carbide substrate rotating while rotating on the rotary table, and An arc discharge is generated by passing a current of 100 A between the layer B and the Ti-Al-Y alloy for forming the lower layer and the anode electrode, so that the target compositions shown in Tables 3 and 4 are formed on the surface of the cemented carbide substrate. And a (Ti, Al, Y) N layer having a single phase structure with a target layer thickness is deposited as a lower layer of the hard coating layer,
(D) Next, nitrogen gas was introduced into the apparatus as a reaction gas to make a reaction atmosphere of 2 Pa, and a DC bias voltage of −100 V was applied to a carbide substrate rotating while rotating on the rotary table, A predetermined current in a range of 50 to 200 A is passed between the cathode electrode and the anode electrode of the Ti-Al-Y alloy for forming the thin layer A to generate an arc discharge, and the surface of the cemented carbide substrate is predetermined. After forming the thin layer A, the arc discharge is stopped, and instead, the thin layer B and the Ti-Al-Y alloy for forming the lower layer are similarly placed between the cathode electrode and the anode electrode. A predetermined current in the range of 50 to 200 A is applied to generate arc discharge to form a thin layer B having a predetermined thickness, then the arc discharge is stopped, and the thin layer A forming Ti-Al-Y is again formed. Alloy cathode electrode and anode The formation of the thin layer A by arc discharge between the electrodes and the formation of the thin layer B by arc discharge between the cathode electrode and the anode electrode of the Ti-Al-Y alloy for forming the thin layer B and the lower layer are alternately repeated. Therefore, on the surface of the cemented carbide substrate, an upper layer composed of alternating layers of the thin layer A and the thin layer B having the target composition and the single target layer thickness shown in Tables 3 and 4 along the layer thickness direction is similarly shown in Tables 3 and 4. The surface coated carbide throwaway tips (hereinafter referred to as the present invention coated carbide tips) 1 to 16 as the present invention coated carbide tools are produced by vapor deposition with the overall target layer thickness shown in FIG. did.

  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—Y alloy having a component composition corresponding to the target composition shown in Table 5 was mounted as a cathode electrode (evaporation source) as a cathode electrode (evaporation source). The apparatus was heated to 500 ° C. with a heater while maintaining a vacuum of 1 Pa or less, and then a −1000 V DC bias voltage was applied to the carbide substrate, and the Ti—Al—Y alloy and anode of the cathode electrode were applied. An electric current of 100 A is passed between the electrodes to generate an arc discharge, so that the surface of the carbide substrate is bombarded with the Ti—Al—Y alloy, and then nitrogen gas is introduced into the apparatus as a reactive gas to 3 Pa. And a bias voltage applied to the cemented carbide substrate is lowered to −100 V to generate an arc discharge between the cathode electrode and the anode electrode of the Ti—Al—Y alloy. Each of A-1 to A-10 and B-1 to B-6 has a (Ti, Al, Y) N layer having a single-phase structure having a target composition and a target layer thickness shown in Table 5. By forming the hard coating layer by vapor deposition, comparative surface-coated carbide throw-away tips (hereinafter referred to as comparative coated carbide tips) 1 to 16 as comparative coated carbide tools corresponding to conventional coated carbide tools are respectively provided. Manufactured.

Next, the coated carbide chips 1 to 16 of the present invention and the comparative coated carbide chip 1 are compared with the above-mentioned various coated carbide chips, all of which are screwed to the tip of the tool steel tool with a fixing jig. About ~ 16
Work material: JIS SUH310 round bar,
Cutting speed: 150 m / min. ,
Cutting depth: 1.2 mm,
Feed: 0.3 mm / rev. ,
Cutting time: 10 minutes,
Dry continuous high-speed cutting test of heat-resistant steel under the conditions (cutting condition A) (normal cutting speed is 100 m / min.),
Work material: Co alloy having the composition of Co43.0-Ni20.0-Cr20.0-Mo4.0-W4.0-Nb4.0-Fe3.0-Mn1.20-C0.40 by mass% Four longitudinal grooved round bars equally spaced in the length direction,
Cutting speed: 120 m / min. ,
Cutting depth: 1.0 mm,
Feed: 0.3 mm / rev. ,
Cutting time: 5 minutes,
A dry interrupted high-speed cutting test of a Co alloy under the following conditions (cutting condition B) (normal cutting speed is 70 m / min.),
Work material: Ni alloy having a composition of Ni52.5-Cr19.0-Fe18.5-Nb5.1-Ti0.9-Al0.5-Mn0.2-Si0.2-C0.04 by mass% Round bar,
Cutting speed: 120 m / min. ,
Cutting depth: 1.2 mm,
Feed: 0.2 mm / rev. ,
Cutting time: 10 minutes,
The dry continuous high-speed cutting test (normal cutting speed was 80 m / min.) Of Ni alloy under the above conditions (cutting condition C) was carried out, and the flank wear width of the cutting edge was measured in any cutting test. The measurement results are shown in Table 6.

(A) As raw material powder, medium coarse WC powder having an average particle size of 5.5 μm, fine WC powder of 0.8 μm, TaC powder of 1.3 μm, NbC powder of 1.2 μm, 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, Co powder of 1.8 μm was prepared, and these raw material powders were blended in the blending composition shown in Table 7, respectively, and added with wax, ball milled in acetone for 24 hours, dried under reduced pressure, and then pressure of 100 MPa Are pressed into various green compacts of a predetermined shape, and these green compacts are heated to a predetermined temperature in the range of 1370 to 1470 ° C. at a heating rate of 7 ° C./min in a vacuum atmosphere of 6 Pa. And after holding at this temperature for 1 hour, As a result, three types of cemented carbide substrate-forming round bar sintered bodies having diameters of 8 mm, 13 mm, and 26 mm were formed. In the combination shown in the above, the diameter × length of the cutting edge is 6 mm × 13 mm, 10 mm × 22 mm, and 20 mm × 45 mm, respectively, and each has a four-blade square shape with a twist angle of 30 degrees. Cemented carbide substrates (end mills) C-1 to C-8 were produced, respectively.
(B) Also, the diameter of the cutting edge part in the combinations shown in Table 7 by machining from high-speed tool steel (JIS / SKH57) materials of three types of diameters of 8 mm, 13 mm, and 26 mm × High-speed tool steel (hereinafter referred to as HSS) base (end mill) E having a four-blade square shape with dimensions of 6 mm × 13 mm, 10 mm × 22 mm, and 20 mm × 45 mm, respectively, and a twist angle of 30 degrees. -1 to E-6 were produced. The dimensions and shapes of the HSS substrates (end mills) E-1 to E-2, E-3 to E-4, and E-5 to E-6 are the same as the carbide substrates (end mills) C-1 to C-3. , C-4 to C-6, and C-7 to C-8.

Next, the surfaces of these carbide substrates (end mills) C-1 to C-8 and HSS substrates (end mills) E-1 to E-6 were ultrasonically cleaned in acetone and dried, as shown in FIG. From the (Ti, Al, Y) N layer having a single phase structure with the target composition and target layer thickness shown in Table 8 under the same conditions as in Example 1 above. The total target layer thickness shown in Table 8 is also the lower layer, and the upper layer consisting of the alternating layers of the thin layer A and the thin layer B having the target composition and the single target layer thickness are also shown in Table 8 along the layer thickness direction. As a surface-coated cutting tool of the present invention, the surface-coated carbide end mill (hereinafter referred to as the present invention coated carbide end mill) 1 to 8 and the surface-coated high-speed tool steel end mill (hereinafter referred to as the present invention) The present invention coated HSS end Le and refers) 9-14 were prepared, respectively.

  For the purpose of comparison, the surfaces of the above-mentioned carbide substrates (end mills) C-1 to C-8 and HSS substrates (end mills) E-1 to E-6 were ultrasonically cleaned in acetone and dried. 2 is charged in the arc ion plating apparatus shown in FIG. 2 and has a single-phase structure with the target composition and target layer thickness shown in Table 9 under the same conditions as in Example 1 (Ti, Al). , Y) By vapor-depositing a hard coating layer composed of an N layer, comparative surface-coated carbide end mills (hereinafter referred to as comparative coated carbide end mills) 1 to 8 and comparative surface-coated high-speed tool steel end mills (hereinafter referred to as 9-14, each of which was referred to as a comparative coated HSS end mill.

(A) Next, of the present invention coated carbide end mills 1-8 and conventional coated carbide end mills 1-8,
(A-1) About this invention coated carbide end mills 1-3 and conventional coated carbide end mills 1-3,
Work material-plane: 100 mm × 250 mm, thickness: mass% with dimensions of 50 mm, Ni52.5-Cr19.0-Fe18.5-Nb5.1-Ti0.9-Al0.5-Mn0.2 A Ni alloy plate having a composition of -Si0.2-C0.04,
Cutting speed: 60 m / min. ,
Groove depth (cut): 3 mm,
Table feed: 120 mm / min,
A dry high-speed grooving test of the Ni alloy under the conditions (normal cutting speed is 35 m / min.),
(A-2) About this invention coated carbide end mills 4-6 and conventional coated carbide end mills 4-6,
Work material-Plane: 100 mm × 250 mm, thickness: 50 mm plate material of JIS / SUH310,
Cutting speed: 80 m / min. ,
Groove depth (cut): 5 mm,
Table feed: 120 mm / min,
A dry high-speed grooving test of the heat-resistant steel under the conditions (normal cutting speed is 40 m / min.),
(A-3) About the coated carbide end mills 7 and 8 of the present invention and the conventional coated carbide end mills 7 and 8,
Work material-plane: 100 mm × 250 mm, thickness: 50% by weight, Co43.0-Ni20.0-Cr20.0-Mo4.0-W4.0-Nb4.0-Fe3.0 -Co alloy plate material having a composition of Mn1.20-C0.40,
Cutting speed: 70 m / min. ,
Groove depth (cut): 10 mm,
Table feed: 110 mm / min,
A dry high-speed grooving test of the Co alloy under the conditions (normal cutting speed is 40 m / min.),
In any of the above groove cutting tests (a-1) to (a-3), the cutting groove length until the flank wear width of the outer peripheral edge of the cutting edge reaches 0.1 mm, which is a guide for the service life. Was measured.

(B) Next, among the coated HSS end mills 9 to 14 and the comparative coated HSS end mills 9 to 14 of the present invention,

(B-1) About the present coated HSS end mills 9 and 10 and the conventional coated HSS end mills 9 and 10,

Work material-plane: 100 mm × 250 mm, thickness: mass% with dimensions of 50 mm, Ni52.5-Cr19.0-Fe18.5-Nb5.1-Ti0.9-Al0.5-Mn0.2 A Ni alloy plate having a composition of -Si0.2-C0.04,
Cutting speed: 40 m / min. ,
Groove depth (cut): 2 mm,
Table feed: 100 mm / min,
A dry high-speed grooving test of the alloy under the conditions (normal cutting speed is 20 m / min.)
(B-2) About this invention coated HSS end mills 11 and 12 and conventional coated HSS end mills 11 and 12,
Work material-Plane: 100 mm × 250 mm, thickness: 50 mm plate material of JIS / SUH310,
Cutting speed: 50 m / min. ,
Groove depth (cut): 3 mm,
Table feed: 90 mm / min,

A dry high-speed grooving test of the heat-resistant steel under the conditions (normal cutting speed is 25 m / min.),

(B-3) About this invention coated HSS end mills 13 and 14 and conventional coated HSS end mills 13 and 14,
Work material-plane: 100 mm × 250 mm, thickness: 50% by weight, Co43.0-Ni20.0-Cr20.0-Mo4.0-W4.0-Nb4.0-Fe3.0 -Co alloy plate material having a composition of Mn1.20-C0.40,
Cutting speed: 40 m / min. ,
Groove depth (cut): 6 mm,
Table feed: 85 mm / min,

A dry high-speed grooving test of the Co alloy under the conditions (normal cutting speed is 20 m / min.),

In any of the groove cutting tests of (b-1) to (b-3) above, the cutting groove length until the flank wear width of the outer peripheral edge of the cutting edge reaches 0.1 mm, which is a guide for the service life. Was measured.
The measurement results of the above (a-1) to (a-3) and (b-1) to (b-3) are shown in Tables 8 and 9, 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), 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), respectively. 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.

In addition, the high speed tool steel (JIS / SKH57) material used in Example 2 above was used, and the diameter x length of the groove forming portion was 4 mm × 13 mm (HSS bases F-1, F- 2), 8 mm × 22 mm (HSS bases F-3, F-4) and 16 mm × 45 mm (HSS bases F-5, F-6), and each has a two-blade shape with a twist angle of 30 degrees. HSS substrates (drills) F-1 to F-6 made of high-speed tool steel were produced.

  Next, the cutting edges of these carbide substrates (drills) D-1 to D-8 and HSS substrates (drills) F-1 to F-6 are honed, ultrasonically cleaned in acetone, and dried. In the same manner, the arc ion plating apparatus shown in FIG. 1 was charged, and under the same conditions as in Example 1, it had a single phase structure with the target composition and target layer thickness shown in Table 10 (Ti, Al , Y) The lower layer consisting of N layers and the upper layer consisting of alternating layers of the thin layer A and the thin layer B with the target composition and the single target layer thickness also shown in Table 10 along the layer thickness direction are also shown in Table 10 By carrying out vapor deposition with the overall target layer thickness shown, the present invention surface coated carbide drills (hereinafter referred to as the present invention coated carbide drill) 1 to 8 as the present invention surface coated cutting tool and the present invention surface coated HSS. Drill (hereinafter referred to as the present invention coated HSS drill) Say) 9 to 14 were prepared, respectively.

For comparison purposes, the surfaces of the above-mentioned carbide substrates (drills) D-1 to D-8 and HSS substrates (drills) F-1 to F-6 are subjected to honing and ultrasonically cleaned in acetone. In a dry state, the same was put into the arc ion plating apparatus shown in FIG. 2, and under the same conditions as in Example 1, a single phase structure with the target composition and target layer thickness also shown in Table 11 was obtained. By vapor-depositing a hard coating layer comprising a (Ti, Al, Y) N layer, a comparative surface-coated carbide drill (hereinafter referred to as a comparative coated carbide drill) 1 to 8 and a comparative surface-coated HSS drill (hereinafter referred to as a comparative surface coated carbide drill) (Referred to as comparative coated HSS drills) 9-14.

(C) Next, of the present invention coated carbide drills 1-8 and conventional coated carbide drills 1-8,
(C-1) About this invention coated carbide drills 1-3 and conventional coated carbide drills 1-3,

Work material-plane: 100 mm × 250, thickness: mass% with dimensions of 50 mm, Co43.0-Ni20.0-Cr20.0-Mo4.0-W4.0-Nb4.0-Fe3.0 -Co alloy plate material having a composition of Mn1.20-C0.40,

Cutting speed: 90 m / min. ,
Feed: 0.15 mm / rev,
Hole depth: 8 mm,
A wet high speed drilling test of the Co alloy under the conditions (normal cutting speed is 60 m / min.),
(C-2) About the present coated carbide drills 4-6 and the conventional coated carbide drills 4-6,
Work material-plane: 100 mm × 250 mm, thickness: 50% by mass, Ni52.5-Cr19.0-Fe18.5-Nb5.1-Ti0.9-Al0.5-Mn0.2 -Ni alloy plate material having a composition of -Si0.02-C0.04,
Cutting speed: 80 m / min. ,
Feed: 0.25 mm / rev,
Hole depth: 16 mm,
A wet high-speed drilling test of the Ni alloy under the conditions (normal cutting speed is 50 m / min.),
(C-3) About the coated carbide drills 7 and 8 of the present invention and the conventional coated carbide drills 7 and 8,
Work material-Plane: 100 mm × 250 mm, thickness: 50 mm plate material of JIS / SUH310,
Cutting speed: 70 m / min. ,
Feed: 0.30 mm / rev,
Hole depth: 32 mm,
Wet high-speed drilling test of heat-resistant steel under the conditions (normal cutting speed is 35 m / min.)
In any of the wet high-speed drilling tests (using water-soluble cutting oil) of any of the above (c-1) to (c-3), the number of drilling processes until the flank wear width of the tip cutting edge surface reaches 0.3 mm Was measured.

(D) Next, among the above-mentioned present invention coated HSS drills 9-14 and conventional coated HSS drills 9-14,
(D-1) For the coated HSS drills 9 and 10 of the present invention and the conventional coated HSS drills 9 and 10,

Work material-plane: 100 mm × 250, thickness: mass% with dimensions of 50 mm, Co43.0-Ni20.0-Cr20.0-Mo4.0-W4.0-Nb4.0-Fe3.0 -Co alloy plate material having a composition of Mn1.20-C0.40,

Cutting speed: 40 m / min. ,
Feed: 0.15 mm / rev,
Hole depth: 8 mm,
A wet high speed drilling test of the Co alloy under the conditions (normal cutting speed is 20 m / min.),
(D-2) About this invention coated HSS drills 11 and 12 and conventional coated HSS drills 11 and 12,
Work material-plane: 100 mm × 250 mm, thickness: 50% by mass, Ni52.5-Cr19.0-Fe18.5-Nb5.1-Ti0.9-Al0.5-Mn0.2 -Ni alloy plate material having a composition of -Si0.02-C0.04,
Cutting speed: 30 m / min. ,
Feed: 0.15 mm / rev,
Hole depth: 16 mm,
A wet high-speed drilling test of Ni alloy under the conditions (normal cutting speed is 15 m / min.),
(D-3) About this invention coated HSS drills 13 and 14 and conventional coated HSS drills 13 and 14,

Work material-Plane: 100 mm × 250 mm, thickness: 50 mm plate material of JIS / SUH310,
Cutting speed: 30 m / min. ,
Feed: 0.30 mm / rev,
Hole depth: 32 mm,
Wet high-speed drilling test of heat-resistant steel under the conditions (normal cutting speed is 15 m / min.)

In any of the wet high-speed drilling tests (using water-soluble cutting oil) in any of the above (d-1) to (d-3), the number of drilling processes until the flank wear width of the tip cutting edge surface reaches 0.3 mm Was measured.
The measurement results of the above (c-1) to (c-3) and (d-1) to (d-3) are shown in Tables 10 and 11, respectively.

  As a result, the present coated carbide tips 1 to 16 as the present surface coated cutting tool, the present coated carbide end mill 1 to 8, the present coated HSS end mill 9 to 14, the present coated carbide drill 1 to 8 and the present invention coated HSS drills 9-14 (Ti, Al, Y) N hard coating layer composed of (Ti, Al, Y) N, upper layer thin layer A and thin layer B, further composition of the lower layer, and comparative coating super It consists of (Ti, Al, Y) N of hard tips 1-16, comparative coated carbide end mills 1-8, comparative coated HSS end mills 9-14, comparative coated carbide drills 1-8, and comparative coated HSS drills 9-14. When the composition of the hard coating layer was measured by an energy dispersive X-ray analysis method using a transmission electron microscope, the composition was substantially the same as the target composition.

  Further, when the average layer thickness of the constituent layers of the hard coating layer was subjected to cross-sectional measurement using a transmission 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 11, the surface-coated cutting tool of the present invention has an upper layer in which the hard coating layer has an alternately laminated structure of thin layers A and B each having an average layer thickness of 5 to 20 nm. (Having an average layer thickness of 0.5 to 1.5 μm) and a lower layer having a single phase structure (having an average layer thickness of 2 to 6 μm), the upper layer having a predetermined high temperature hardness and heat resistance It has excellent high-temperature oxidation resistance while maintaining its properties, and since the lower layer has excellent high-temperature hardness and heat resistance, the hard coating layer comprehensively exhibits these excellent characteristics. Even when used in high-speed cutting with high heat generation of heat-resistant alloys such as heat-resistant steel, Co alloy, and Ni alloy, the progress of wear of the hard coating layer is suppressed. Whereas the hard coating layer has a single phase structure (Ti , Al, Y) The comparative coated cutting tool consisting of N layer wears due to insufficient high-temperature oxidation resistance of the hard coating layer in high-speed cutting of the heat-resistant alloy. As a result, it is used in a relatively short time. It is clear that it reaches the end of its life.

  As described above, the surface-coated cutting tool according to the present invention involves not only cutting under high-speed cutting conditions such as various carbon steels, low alloy steels, and ordinary cast iron, but also particularly high heat generation of heat resistant alloys. Excellent wear resistance even during high-speed cutting, excellent cutting performance over a long period of time, and versatility for work materials. In addition, it can cope with the cost reduction sufficiently satisfactorily.

The arc ion plating apparatus used for forming the hard coating layer which comprises the surface coating cutting tool of this invention 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 a cemented carbide substrate made of tungsten carbide-based cemented carbide or titanium carbonitride-based cermet, or on the surface of a high-speed tool steel substrate,
(A) Both are composed of an upper layer and a lower layer made of a composite nitride of Ti, Al and Y (yttrium), the upper layer being an average layer of 0.5 to 1.5 μm, and the lower layer being an average layer of 2 to 6 μm Each has a thickness,
(B) Each of the upper layers has an alternately laminated structure of thin layers A and B each having an average layer thickness of 5 to 20 nm (nanometer),
The thin layer A is
Ti satisfying the composition formula: [Ti _{1- (A + B)} Al _A Y _B ] N (wherein A is 0.15 to 0.30 and B is 0.15 to 0.30 in atomic ratio) A composite nitride layer of Al and Y;
The thin layer B is
Ti satisfying the composition formula: [Ti _{1-(C + D)} Al _C Y _D ] N (wherein C is 0.50 to 0.65 and D is 0.01 to 0.10 in atomic ratio) A composite nitride layer of Al and Y,
(C) the lower layer has a single phase structure;
_{Formula: [Ti 1- (E + F} ) Al E Y F] N ( provided that an atomic ratio, E is 0.50 to .65, F denotes the 0.01-0.10) and Ti which satisfies A composite nitride layer of Al and Y;
A surface-coated cutting tool that exhibits excellent wear resistance in high-speed cutting of a heat-resistant alloy, formed by vapor-depositing a hard coating layer comprising

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