JP5783462B2 - Surface coated cutting tool - Google Patents

Description

  The present invention relates to a surface-coated cutting tool (hereinafter referred to as a coated tool). More specifically, for example, a difficult-to-cut material such as titanium alloy steel, heat-resistant alloy steel, and stainless steel is generated with high heat generation and applied to a cutting edge portion. The present invention relates to a coated tool that exhibits excellent heat resistance and wear resistance with a hard coating layer when it is machined under high-speed cutting conditions with remarkable impact and weldability.

  In general, coated tools are used for turning and planing of work materials such as various types of steel and cast iron, inserts that can be used detachably attached to the tip of a cutting tool, drilling processing of work materials, etc. There are drills, miniature drills, solid type end mills used for chamfering, grooving, shoulder processing, etc. of the work material, etc. Also, inserts are detachably attached and cutting is performed in the same way as solid type end mills Throwaway end mill tools are known.

  Further, as a conventional coated tool, for example, a hard coating layer in which a layer made of a carbide, nitride or carbonitride of Zr and a layer made of Al carbide, nitride or carbonitride are alternately laminated on the surface of the tool base. A coating tool provided with Zr is also known, and in particular, Zr carbide, nitride or carbonitride, which is a constituent component, increases the adhesion strength with the base material and increases the hardness of the hard coating layer. Further, Al carbide, nitride or carbonitride improves the fracture resistance of the hard coating layer, and at the same time makes the crystal grains finer by dissolving in the Zr carbide, nitride or carbonitride layer. . Therefore, it is also known that the wear resistance, welding resistance, and fracture resistance of the hard coating layer as a whole are improved by the synergistic action of these laminated layers (see, for example, Patent Document 1). .

  In addition, as another conventional coated tool, a hard coating layer composed of an (Al, Ti, M) N layer is vapor-deposited on the surface of the tool base, thereby improving the wear resistance and fracture resistance. Such a hard coating layer is obtained, for example, by inserting a tool base into an arc ion plating apparatus (AIP apparatus) which is one type of physical vapor deposition apparatus shown schematically in FIG. In a state heated to a temperature of 500 ° C., a cathode electrode in which an alloy corresponding to the composition of the hard coating layer is set, for example, an Al—Ti—M alloy, and an anode electrode, for example, current: 90 A Arc discharge is generated under the conditions, and simultaneously, nitrogen gas is introduced as a reaction gas into the apparatus to form a reaction atmosphere of, for example, 2 Pa. On the other hand, for example, a bias voltage of −100 V is applied to the tool base. In, it is also known to be produced by depositing the tool substrate surface (Al, Ti, M) a hard coating layer consisting of N layers (e.g., see Patent Document 2).

JP-A-4-17663 Japanese Patent No. 2793773

  However, in recent years, the FA of cutting machines has been remarkable. On the other hand, there has been a strong demand for labor saving and energy saving and further cost reduction for cutting, and as a result, cutting tools have as much influence on the type of work material as possible. Versatility, that is, there is a tendency to require a cutting tool capable of cutting as many grades as possible, but in the conventional coated tool, this is a titanium alloy steel, a heat resistant alloy steel, a stainless steel, etc. There is no problem when these materials are used for cutting at normal cutting speeds. However, these materials have high heat generation, and have high impact resistance and weldability to the cutting edge. When cutting with, the work material and chips are heated to a high temperature due to the heat generated during cutting, and the viscosity increases, and as a result, the weldability to the surface of the hard coating layer further increases. Fruit, increased chipping (minute chipping) rapidly at the cutting edge, which is at present, leading to a relatively short time service life due.

  Therefore, the technical problem to be solved by the present invention, that is, the object of the present invention is to provide a coating that exhibits excellent impact resistance, lubricity and wear resistance even when cutting under high-speed cutting conditions with high heat generation. Is to provide a tool.

  In view of the above, the inventors of the present invention have a hard coating layer in particular when cutting difficult-to-cut materials such as titanium alloy steel, heat-resistant alloy steel, and stainless steel under high-speed cutting conditions. As a result of diligent research to develop a coated tool with excellent impact resistance, lubricity and wear resistance, the (Al, Ti) N layer, which is a hard coating layer of a conventional coated tool, is formed on the surface of the tool base. Is formed with an average layer thickness of 0.5 to 5 μm as a lower layer, and a V component is contained thereon so that the content ratio of V in the total amount of Zr and V is 1 to 30 atomic%. When a Zr and V composite nitride layer (hereinafter referred to as a (Zr, V) N layer) is formed as an upper layer with an average layer thickness of 0.5 to 5 μm, a lower (Al, Ti) N layer Shows excellent wear resistance and is contained in the (Zr, V) N layer of the upper layer. Since the r component exhibits high hardness and the V component exhibits lubricity, the (Zr, V) N layer exhibits excellent impact resistance and lubricity, resulting in high heat generation and a work material. Even when used for high-speed cutting with remarkable welding chipping, the progress of wear of the cutting edge is suppressed, and excellent wear resistance is exhibited over a long period of time. Therefore, in high-speed cutting of difficult-to-cut materials, even if the cutting edge becomes hot, it has excellent heat resistance. As a result, the occurrence of chipping (small chipping) in the cutting edge is suppressed, and it has been excellent over a long period of time. The inventors have obtained new knowledge that wear resistance is exhibited, and have completed the present invention based on such knowledge.

  Furthermore, a (Al, Ti) N thin layer having an average layer thickness of 0.01 to 0.1 μm is vapor-deposited on the surface of the tool base, and the content ratio of V in the total amount of Zr and V is further formed thereon. Average layer thickness of 0.01 to 0.1 μm consisting of a composite nitride layer of Zr and V (hereinafter referred to as a (Zr, V) N layer) containing V component so that is 1 to 30 atomic%. The (Zr, V) N thin layer is vapor-deposited, and the (Al, Ti) N thin layer and the (Zr, V) N thin layer are alternately formed to have a total average layer thickness of 1 to 5 μm. (Al, Ti) N thin layers exhibit excellent high-temperature hardness, high-temperature strength, heat resistance, and wear resistance, and are alternately laminated. The (Zr, V) N thin layer exhibits excellent impact resistance and lubricity, and in particular due to the V component contained in the (Zr, V) N thin layer. In addition, since the lubricity of the (Zr, V) N thin layer is improved, it has been found that the excellent welding resistance of the (Zr, V) N thin layer is maintained even in the cutting process with high heat generation. .

Therefore, in high-speed cutting of difficult-to-cut materials such as titanium alloy steel, heat-resistant alloy steel, and stainless steel, even if the cutting edge portion becomes high temperature, the (Al, Ti) N thin layer lacks the welding resistance, The (Zr, V) N thin layer laminated alternately is supplemented, and the wear resistance with the work material as the entire hard coating layer is improved, and as a result, chipping (small chipping) in the cutting edge portion is improved. The inventors have obtained new knowledge that generation is prevented and excellent wear resistance is exhibited over a long period of time, and the present invention has been achieved based on such knowledge.
The present invention has been made based on the research results,
“(1) In a surface-coated cutting tool in which a hard coating layer is formed on the surface of a tool base composed of tungsten carbide-based cemented carbide or titanium carbonitride-based cermet,
The hard coating layer is
(A) having an average layer thickness of 0.5-5 μm, and
Composition formula: (Al _1-x Ti _x ) N (where x represents the content ratio of Ti in the total amount of Al and Ti, and the atomic ratio is 0.30 ≦ x ≦ 0.75) A lower layer composed of a satisfactory nitride layer of Al and Ti;
(B) having an average layer thickness of 0.5-5 μm, and
Composition formula: (Zr _1-a V _a ) N (where a represents the content ratio of V in the total amount of Zr and V, and the atomic ratio is 0.01 ≦ a ≦ 0.30) A surface-coated cutting tool comprising a satisfactory upper layer made of a composite nitride layer of Zr and V.
(2) In a surface-coated cutting tool formed by forming a hard coating layer on the surface of a tool base composed of a tungsten carbide-based cemented carbide or a titanium carbonitride-based cermet,
The hard coating layer is
(A) having an average layer thickness of 0.01 to 0.1 μm, and
Composition formula: (Al _1-x Ti _x ) N (where x represents the content ratio of Ti in the total amount of Al and Ti, and the atomic ratio is 0.30 ≦ x ≦ 0.75) (Al, Ti) N thin layer consisting of a satisfactory nitride layer of Al and Ti,
(B) having an average layer thickness of 0.01 to 0.1 μm, and
Composition formula: (Zr _1-a V _a ) N (where a represents the content ratio of V in the total amount of Zr and V, and the atomic ratio is 0.01 ≦ a ≦ 0.30) A (Zr, V) N thin layer consisting of a satisfactory composite layer of Zr and V,
A surface-coated cutting tool comprising the alternating lamination of (a) and (b) and having a total average layer thickness of 1 to 5 μm. "
It is characterized by.

  Next, the reason why the numerical values of the constituent layers of the hard coating layer of the coated tool of the present invention are limited as described above will be described.

(A) Composition and average layer thickness or single layer average film of (Al, Ti) N layers constituting one layer of the alternate layer in the invention described in (2) and the lower layer in the invention described in (1) Thickness:
The Al component, which is a constituent component of the (Al, Ti) N layer constituting one of the lower layer or the alternating layer, improves the high temperature hardness of the hard coating layer, and the Ti component improves the high temperature strength. However, when the x value indicating the Ti content is less than 0.30 in terms of the total amount with Al (atomic ratio, the same shall apply hereinafter), a predetermined high-temperature strength cannot be ensured, On the other hand, if the x value indicating the Ti content exceeds 0.75, the Al content decreases relatively, ensuring high-temperature hardness required for high-speed cutting. The x value is set to 0.30 to 0.75 because it is difficult to prevent chipping from occurring.

Further, if the average layer thickness of the (Al, Ti) N layer constituting the lower layer is less than 0.5 μm, it is insufficient to exhibit the excellent wear resistance of itself for a long time, If the average layer thickness exceeds 5 μm, chipping is likely to occur at the cutting edge portion in the high-speed cutting, so the average layer thickness was set to 0.5 to 5 μm.
Further, if the average layer thickness of the (Al, Ti) N layers constituting one layer of the alternately laminated layer is less than 0.01 μm, it is not sufficient for exhibiting the excellent wear resistance of itself for a long period of time. On the other hand, if the average layer thickness exceeds 0.1 μm, the high-speed cutting reveals insufficient welding resistance, and chipping tends to occur at the cutting edge. It was determined to be 0.01 to 0.1 μm.

(C) Composition and average layer thickness or single layer average film of the upper layer in the invention described in (1) and the (Zr, V) N layer constituting one of the alternately laminated layers in the invention described in (2) Thickness:
The (Zr, V) N layer composed of a composite nitride of Zr and V constituting the upper layer of the (Al, Ti) N layer or one of the alternately laminated layers has a predetermined high temperature hardness, high temperature strength, and heat resistance. In addition, the V component which is a constituent component provides excellent lubricity, and the Zr component supplements high hardness. Therefore, a low coefficient of friction is maintained even under high-temperature cutting conditions, and excellent heat resistance is exhibited, but the ratio of the a value indicating the V content to the total amount with Zr (atomic ratio, the same applies hereinafter) If it is less than 0.01, it is not possible to expect welding resistance since lubricity cannot be ensured. On the other hand, if the a value indicating the content ratio of V exceeds 0.30, relative In addition, the content ratio of Zr is reduced, and not only the impact resistance required for high-speed cutting of difficult-to-cut materials cannot be ensured, but also the wear resistance is lowered and it becomes difficult to prevent the occurrence of chipping. Therefore, the a value was determined to be 0.01 to 0.30 (atomic ratio, the same applies hereinafter).

Further, if the average layer thickness of the (Zr, V) N layer constituting the upper layer is less than 0.5 μm, it is insufficient to exhibit its excellent wear resistance over a long period of time. If the average layer thickness exceeds 5 μm, chipping is likely to occur at the cutting edge portion in the high-speed cutting, so the average layer thickness was set to 0.5 to 5 μm.
In addition, if the average layer thickness of the (Zr, V) N layers constituting one layer of the alternately laminated layer is less than 0.01 μm, it is not sufficient to exhibit the excellent wear resistance of itself for a long period of time. On the other hand, if the average layer thickness exceeds 0.1 μm, insufficient wear resistance becomes apparent in the high-speed cutting, and chipping tends to occur at the cutting edge. It was determined to be 0.01 to 0.1 μm.

  The (Al, Ti) N layer and (Zr, V) N layer are prepared by, for example, loading a substrate into an arc ion plating apparatus which is a kind of physical vapor deposition apparatus shown in FIG. A cathode electrode (evaporation source) made of a Zr—V alloy having a predetermined composition is placed in the apparatus while the inside of the apparatus is heated to a temperature of, for example, 500 ° C. with a heater, and an Al—Ti alloy having a predetermined composition The cathode electrode (evaporation source) is arranged, and an arc discharge is generated between the anode electrode and the cathode electrode (evaporation source), for example, under the condition of current: 110 A. Simultaneously, nitrogen gas is supplied as a reaction gas in the apparatus. For example, the reaction atmosphere is set to 3 Pa, while the substrate is vapor-deposited, for example, under the condition that a bias voltage of −150 V is applied, to form a lower layer made of the (Al, Ti) layer and (Zr , ) The hard coating layer of the present invention can be formed by vapor deposition by depositing two layers of the upper layer consisting of the N layer, or by alternately laminating the (Al, Ti) layer and the (Zr, V) N layer. it can.

According to one aspect of the coated tool of the present invention, the hard coating layer having a two-layer structure of the lower layer made of the (Al, Ti) N layer and the upper layer made of the (Zr, V) N layer has excellent high-temperature hardness. Because it has heat resistance, high temperature strength, wear resistance, lubricity, and impact resistance, the hard coating layer as a whole has excellent welding resistance in addition to excellent high temperature hardness, heat resistance, high temperature strength, etc. As a result, especially with the high heat generation of difficult-to-cut materials such as titanium steel alloy, heat-resistant alloy steel, stainless steel, etc. It exhibits impact resistance and exhibits excellent chipping resistance and wear resistance over a long period of time.
Further, according to another aspect of the coated tool of the present invention, when the hard coating layer is composed of an alternately laminated structure and one layer is composed of an (Al, Ti) N thin layer, excellent high-temperature hardness and high-temperature strength. Or (Zr, V) N thin layer constituting the other layer has both excellent impact resistance and lubricity, so that it is hard. The coating layer as a whole has excellent high-temperature hardness, high-temperature strength, etc., as well as excellent wear resistance. As a result, especially for difficult-to-cut materials such as titanium alloy steel, heat-resistant alloy steel, and stainless steel. Even with high-speed cutting with significant heat generation and remarkable weldability to the cutting edge, it exhibits excellent chipping resistance, suppresses the progress of wear on the cutting edge, and has excellent wear resistance over a long period of time To demonstrate.

The arc ion plating apparatus used for forming the hard coating layer which comprises this invention coated tool is shown, (a) is a schematic plan view, (b) is a schematic front view. It is a schematic explanatory drawing of the conventional arc ion plating apparatus used in forming the hard coating layer which comprises a comparative coating tool.

  Next, the coated 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, and Co powder all having an average particle diameter of 1 to 3 μm are used. Prepared, these raw material powders were blended in the composition shown in Table 1, wet-mixed for 72 hours with a ball mill, dried, and then pressed into a green compact at a pressure of 100 MPa. Sintered in vacuum at a temperature of 1400 ° C. for 1 hour. After sintering, tool bases A-1 to A-10 made of WC-base cemented carbide with ISO standard / CNMG120408 insert shape are formed. did.

Moreover, as raw material powders, TiCN (mass ratio, TiC / TiN = 50/50) powder, Mo ₂ C powder, ZrC powder, NbC powder, TaC powder, all having an average particle diameter of 0.5 to 2 μm, 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 into a compact at a pressure of 100 MPa. This compact is sintered in a 2 kPa nitrogen atmosphere at a temperature of 1500 ° C. for 1 hour, and after sintering, a tool made of TiCN-based cermet having an ISO standard / CNMG120408 insert shape Bases B-1 to B-6 were formed.

(A) Next, each of the tool bases 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. It is mounted along the outer periphery at a position that is a predetermined distance in the radial direction from the central axis on the inner rotary table, and cathode electrodes (evaporation sources) are arranged on both sides facing each other across the rotary table. Has a Zr-V alloy having a predetermined composition as a cathode electrode (evaporation source) and an Al-Ti alloy having a predetermined composition as a cathode electrode (evaporation source). Place and
(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 tool base that rotates while rotating on the rotary table is −1000 V. And applying a current of 100 A between the cathode electrode and the anode electrode to generate an arc discharge, thereby bombarding the surface of the tool base,
(C) Next, nitrogen gas is introduced as a reaction gas into the apparatus to form a reaction atmosphere of 4 Pa, a DC bias voltage of −100 V is applied to the tool base that rotates while rotating on the rotary table, and Arc current is generated by flowing a current of 120 A between either the Zr-V alloy or Al-Ti alloy of the cathode electrode and the anode electrode, and the target composition and target shown in Table 3 are formed on the surface of the tool base. After the (Al, Ti) N layer as the lower layer of the layer thickness is vapor-deposited with an average layer thickness of 0.5 to 5 μm, the arc discharge between the cathode electrode (evaporation source) and the anode electrode is stopped,
(D) Subsequently, an arc discharge is generated by flowing a current of 120 A between the Zr-V alloy electrode, which is the cathode electrode (evaporation source), and the anode electrode while maintaining the atmosphere in the apparatus in a nitrogen atmosphere of 2 Pa. Then, the upper layer composed of the (Zr, V) N layer having the target composition and target layer thickness shown in Table 3 is formed by vapor deposition.
A hard coating layer was formed by vapor deposition according to the above (a) to (d), and surface coated inserts (hereinafter referred to as the present coated inserts) 1 to 16 as the coated tools of the present invention were produced.

  For comparison purposes, these tool bases A-1 to A-10 and B-1 to B-6 were ultrasonically cleaned in acetone and dried, respectively, and the arc ion plating shown in FIG. The device is charged with Al-Ti alloy and Zr-V alloy having a predetermined composition as cathode electrodes (evaporation source). First, the device 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 tool base, and a current of 150 A is passed between the cathode electrode Al—Ti alloy and the anode electrode to generate arc discharge, Accordingly, the surface of the tool base is bombarded with the Al—Ti alloy, and then nitrogen gas is introduced into the apparatus as a reaction gas to form a reaction atmosphere of 2 Pa, and a via applied to the tool base. The voltage is lowered to −90 V, and arc discharge is generated between each cathode electrode and anode electrode having the predetermined composition, whereby each of the tool bases A-1 to A-10 and B-1 to B-6. On the surface, a conventional hard coating layer composed of an (Al, Ti) N layer having a target composition and target layer thickness shown in Table 4, and a lower layer (Al, target layer thickness and target layer also shown in Table 4) Surface coating insert as a comparative coating tool (hereinafter referred to as comparative coating insert) by vapor-depositing a conventional hard coating layer composed of a Ti) N layer and an upper layer (Zr, V) N layer having a target composition and target layer thickness 1) to 8 were produced.

Next, with the various coated inserts, all of the present invention coated inserts 1 to 16 and comparative coated inserts 1 to 8 in a state where all the tool inserts are screwed to the tip of the tool steel tool with a fixing jig.
Work material: JIS / SUS304 (HB200) round bar,
Cutting speed: 145 m / min. ,
Cutting depth: 2.5mm,
Feed: 0.2 mm / rev. ,
Cutting time: 5 minutes
(Continuous cutting speed and feed are 120 m / min. And 0.2 mm / rev., Respectively)
Work material: Ti-6Al-4V alloy (HB250) round bar,
Cutting speed: 60 m / min. ,
Incision: 2 mm,
Feed: 0.2 mm / rev. ,
Cutting time: 5 minutes
Wet continuous high-speed cutting test of Ti alloy under the following conditions (cutting condition B) (normal cutting speed and feed are 40 m / min. And 0.2 mm / rev., Respectively),
Work material: JIS S45C (HB200) round bar,
Cutting speed: 190 m / min. ,
Cutting depth: 2mm,
Feeding: 0.4 mm / rev. ,
Cutting time: 5 minutes
Wet continuous high-speed cutting test of carbon steel under the following conditions (cutting condition C) (normal cutting speed and feed are 160 m / min. And 0.25 mm / rev., Respectively),
The flank wear width of the cutting edge was measured in any high-speed cutting test. The measurement results are shown in Tables 5 and 6.

As in Example 1, all of WC powder, TiC powder, ZrC powder, VC powder, TaC powder, NbC powder, Cr ₃ C ₂ powder, TiN powder, TaN powder, and Co having an average particle diameter of 1 to 3 μm. A raw material powder composed of powder is blended in the blending composition shown in Table 1, wet mixed by a ball mill for 72 hours, dried, and then press-molded into a green compact at a pressure of 100 MPa. Medium temperature: Sintered at 1400 ° C. for 1 hour to form a round tool sintered body for forming a tool base having a diameter of 13 mm. Further, the round bar sintered body was cut by grinding. Manufacture of WC-base cemented carbide tool bases (end mills) A-1 to A-10 having a blade part diameter x length of 10 mm x 22 mm and a 4-blade square shape with a twist angle of 30 degrees did.

  Then, the surfaces of these tool bases (end mills) A-1 to A-10 were ultrasonically cleaned in acetone and dried, and then charged into the arc ion plating apparatus shown in FIG. 1 by coating the hard coating layer comprising the (Zr, V) N layer and (Al, Ti) N layer having the target composition and target layer thickness shown in Table 7 under the same conditions as in Table 1. The present invention surface-coated carbide end mills (hereinafter referred to as the present invention-coated end mills) 1 to 15 were produced.

  For comparison purposes, the surfaces of the tool bases (end mills) A-1 to A-10 are ultrasonically cleaned in acetone and dried, and then loaded into the arc ion plating apparatus shown in FIG. Then, under the same conditions as in Example 1, the conventional hard coating layer composed of the (Al, Ti) N layer having the target composition and target layer thickness shown in Table 8, and the target composition and target layer thickness also shown in Table 8 The conventional hard coating layer composed of a lower layer (Al, Ti) N layer and an upper layer (Zr, V) N layer having a target composition and target thickness is vapor-deposited to provide a surface-coated carbide as a comparative coating tool. End mills (hereinafter referred to as comparative coated end mills) 1 to 8 were produced.

Next, for the present invention coated end mills 1-15 and comparative coated end mills 1-8,
Work material—planar dimensions: 100 mm × 250 mm, thickness: 50 mm JIS / SUS304 (HB200) plate material,
Cutting speed: 110 m / min. ,
Groove depth (cut): 15 mm,
Table feed: 300mm / min,
Wet high-speed grooving test of stainless steel under the following conditions (cutting condition D) (normal cutting speed and table feed are 90 m / min, 280 mm / min, respectively),
Work material—planar dimensions: 100 mm × 250 mm, thickness: 50 mm Ti-6Al-4V alloy (HB250) plate,
Cutting speed: 60 m / min. ,
Groove depth (cut): 15 mm,
Table feed: 110mm / min,
Wet high-speed grooving test of Ti alloy under the conditions (cutting condition E) (normal cutting speed and table feed are 40 m / min. And 90 mm / min, respectively),
Work material-Plane dimensions: 100 mm x 250 mm, thickness: 50 mm JIS S45C (HB200) plate,
Cutting speed: 220 m / min. ,
Groove depth (cut): 15 mm,
Table feed: 720mm / min,
Wet high-speed grooving test of carbon steel under the following conditions (cutting condition F) (normal cutting speed and table feed are 200 m / min. And 600 mm / min, respectively),
In each high-speed groove cutting test, the cutting groove length was measured until the flank wear width of the outer peripheral edge of the cutting edge reached 0.1 mm, which is a guide for the service life. The measurement results are also shown in Tables 7 and 8, respectively.

  The round bar sintered body with a diameter of 13 mm manufactured in Example 2 was used, and from this round bar sintered body, the dimensions of the groove forming part diameter × length were 8 mm × 22 mm and the twist angle by grinding. WC-base cemented carbide tool bases (drills) A-1 to A-10 having a 30-degree two-blade shape were produced, respectively.

  Next, the cutting edges of these tool bases (drills) A-1 to A-10 are subjected to honing, ultrasonically cleaned in acetone, and dried to the arc ion plating apparatus shown in FIG. The hard coating layer consisting of the (Zr, V) N layer and (Al, Ti) N layer having the target composition and target layer thickness shown in Table 9 is deposited under the same conditions as in Example 1. Thus, the surface-coated carbide drills (hereinafter referred to as the present invention-coated drills) 1 to 15 as the present invention-coated tools were produced, respectively.

  For the purpose of comparison, honing is performed on the surfaces of the tool bases (drills) A-1 to A-10, ultrasonic cleaning is performed in acetone, and the arc ion plate shown in FIG. A conventional hard coating layer composed of an (Al, Ti) N layer having the target composition and target layer thickness shown in Table 10 under the same conditions as in Example 1 and the same as shown in Table 10 The conventional hard coating layer composed of the lower layer (Al, Ti) N layer having the target composition and target layer thickness and the upper layer (Zr, V) N layer having the target composition and target layer thickness is formed by vapor deposition. Surface coated carbide drills (hereinafter referred to as comparative coated drills) 1 to 8 as coated tools were produced, respectively.

Next, for the present invention coated drills 1-15 and comparative coated drills 1-8,
Work material-planar dimensions: 100 mm × 250 mm, thickness: 50 mm JIS / SUS304 (HB200) plate material,
Cutting speed: 100 m / min. ,
Feed: 0.3 mm / rev. ,
Hole depth: 5mm,
Wet high-speed drilling test of stainless steel under the following conditions (cutting condition G) (normal cutting speed and feed are 70 m / min. And 0.2 mm / rev., Respectively),
Work material—planar dimensions: 100 mm × 250 mm, thickness: 50 mm Ti-6Al-4V alloy (HB250) plate material,
Cutting speed: 55 m / min. ,
Feed: 0.2 mm / rev. ,
Hole depth: 5mm,
Wet high-speed drilling test of Ti alloy under the following conditions (cutting condition H) ((normal cutting speed and feed are 40 m / min. And 0.15 mm / rev., Respectively),
Work material-Plane dimensions: 100 mm x 250 mm, thickness: 50 mm JIS S45C (HB200) plate,
Cutting speed: 155 m / min. ,
Feed: 0.25 mm / rev. ,
Hole depth: 5mm,
Wet high-speed drilling test of carbon steel under the following conditions (cutting condition I) (normal cutting speed and feed are 110 m / min. And 0.2 mm / rev., Respectively),
In each wet high-speed drilling test (using water-soluble cutting oil), the number of drilling processes until the flank wear width of the tip cutting edge surface reached 0.3 mm was measured. The measurement results are also shown in Table 9 and Table 10, respectively.

  As a result, the present invention coated tools 1 to 16 of the present invention, the coated end mills 1 to 15 of the present invention, and the lower layer constituting the hard coating layer of the coated drills 1 to 15 of the present invention (Al, Ti ) Composition of the N layer and the upper (Zr, V) N layer, and comparative coated inserts 1-8, comparative coated end mills 1-8 as comparative coated tools, and (Al, When the composition of the hard coating layer composed of the Ti) N layer was measured by energy dispersive X-ray analysis using a transmission electron microscope, it showed substantially the same composition as the target composition.

  Moreover, when the average layer thickness of each layer which comprises the said hard coating layer was cross-sectional measured using the scanning electron microscope, all showed the average value (average value of five places) substantially the same as target layer thickness.

  From the results shown in Tables 3 to 10, when the coated tool of the present invention forms a hard coating layer having a two-layer structure, the (Al, Ti) N layer, which is the lower layer, is tightly bonded to the tool base surface. With excellent high-temperature hardness, heat resistance, and high-temperature strength, excellent welding resistance with chips even in high-speed cutting of difficult-to-cut materials such as titanium alloy steel, heat-resistant alloy steel, and stainless steel As a hard coating layer, the (Zr, V) N layer is not provided as a hard coating layer, while excellent wear resistance is exhibited over a long period of time without occurrence of chipping. In the comparative coated tool composed of only the (Al, Ti) N layer, in all high-speed cutting of the difficult-to-cut material, the work material (hard-to-cut material) and the adhesion between the chips and the hard coating layer. The cutting edge to prevent damage and reactivity. Ring is adapted to generate, it is clear that lead to a relatively short time service life.

WC powder, TiC powder, ZrC powder, VC powder, TaC powder, NbC powder, V 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 into 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, and after sintering, tool bases A-1 to A-10 made of WC-base cemented carbide having an ISO standard / CNMG120408 insert shape were formed. .

In addition, 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 Then, this green compact was sintered in a nitrogen atmosphere of 2 kPa at a temperature of 1500 ° C. for 1 hour, and after sintering, a tool substrate B made of TiCN base cermet having an ISO standard / CNMG120408 insert shape was used. -1 to B-6 were formed.

(A) Next, each of the tool bases 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. It is mounted along the outer periphery at a position that is a predetermined distance in the radial direction from the central axis on the inner rotary table, and cathode electrodes (evaporation sources) are arranged on both sides facing each other across the rotary table. Has an Al—Ti alloy with a predetermined composition as a cathode electrode (evaporation source), and a Zr—V alloy with a predetermined composition as a cathode electrode (evaporation source) on the other side.
(B) First, the inside of the apparatus is heated to 500 ° C. with a heater while the inside of the apparatus is evacuated and kept at a vacuum of 0.1 Pa or less, and then the tool base that rotates while rotating on the rotary table is −1000 V. A DC bias voltage is applied and a current of 100 A is passed between the Al-Ti alloy and the anode electrode of the cathode electrode to generate an arc discharge, whereby the tool base surface is bombarded with the Al-Ti alloy,
(C) Next, nitrogen gas is introduced as a reaction gas into the apparatus to form a reaction atmosphere of 4 Pa, a DC bias voltage of −100 V is applied to the tool base that rotates while rotating on the rotary table, and An arc discharge is generated by flowing a current of 120 A between the Al—Ti alloy of the cathode electrode and the anode electrode, and the target composition shown in Table 11 and (Al, After the Ti) N thin layer is formed by vapor deposition, the arc discharge between the cathode electrode (evaporation source) and the anode electrode of the Al-Ti alloy is stopped,
(D) Subsequently, an arc discharge is generated by flowing a current of 120 A between the Zr-V alloy electrode, which is the cathode electrode (evaporation source), and the anode electrode while maintaining the atmosphere in the apparatus in a nitrogen atmosphere of 2 Pa. Then, the target composition shown in Table 11 and a (Zr, V) N thin layer having a target layer thickness are formed by vapor deposition.
The operations of (c) and (d) are repeated until a predetermined total average layer thickness is obtained, and a hard coating layer is formed by vapor deposition. The surface coating insert of the present invention (hereinafter referred to as the present coating insert) as the present coating tool. 17-32 were produced.

  For comparison purposes, these tool bases A-1 to A-10 and B-1 to B-6 were ultrasonically cleaned in acetone and dried, respectively, and the arc ion plating shown in FIG. The device is charged with an Al-Ti alloy or Zr-V alloy having a predetermined composition as a cathode electrode (evaporation source). First, the device 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 tool base, and an arc discharge is generated by flowing a current of 100 A between the Al—Ti alloy of the cathode electrode and the anode electrode. Thus, the surface of the tool base is bombarded with the Al—Ti alloy, and then nitrogen gas is introduced into the apparatus as a reaction gas to form a reaction atmosphere of 3 Pa. And the arc voltage is generated between each cathode electrode and anode electrode of the predetermined composition, and the tool bases A-1 to A-10 and B-1 to B-6 On the surface, a hard coating layer composed of an (Al, Ti) N layer having a target composition and a target layer thickness shown in Table 12 and a (Zr, V) N layer having a target composition and a target layer thickness is formed by vapor deposition. Thus, surface coated inserts (hereinafter referred to as comparative coated inserts) 9 to 16 as comparative coated tools were manufactured.

Next, with the various coated inserts, the present invention coated inserts 17 to 32 and comparative coated inserts 9 to 16 are all screwed to the tip of the tool steel tool with a fixing jig.
Work material: JIS / SUS304 (HB240) round bar,
Cutting speed: 140 m / min. ,
Cutting depth: 3mm,
Feed: 0.25 mm / rev. ,
Cutting time: 5 minutes
Wet continuous high-speed cutting test of stainless steel under the following conditions (cutting condition a) (normal cutting speed and feed are 100 m / min. And 0.2 mm / rev., Respectively),
Work material: Round bar of Ti-6Al-4V alloy (HB280),
Cutting speed: 55 m / min. ,
Cutting depth: 2.5mm,
Feed: 0.2 mm / rev. ,
Cutting time: 5 minutes
Wet continuous high-speed cutting test of Ti alloy under the following conditions (cutting condition b) (normal cutting speed and feed are 35 m / min. And 0.15 mm / rev., Respectively),
Work material: JIS S45C (HB2 40) round bar,
Cutting speed: 180 m / min. ,
Cutting depth: 2.5mm,
Feed: 0.3 mm / rev. ,
Cutting time: 5 minutes
Wet continuous high-speed cutting test of carbon steel under the following conditions (cutting condition c) (normal cutting speed and feed are 145 m / min. And 0.25 mm / rev., Respectively),
The flank wear width of the cutting edge was measured in any high-speed cutting test. The measurement results are shown in Tables 13 and 14.

As in Example 4, WC powder, TiC powder, ZrC powder, VC powder, TaC powder, NbC powder, V ₃ C ₂ powder, TiN powder, TaN powder, and Co powder all have an average particle diameter of 1 to 3 μm. The raw material powder consisting of the above is blended in the composition shown in Table 1, wet mixed for 72 hours with a ball mill, dried, and then pressed into a green compact at a pressure of 100 MPa. , Temperature: Sintered at 1400 ° C. for 1 hour to form a round tool sintered body for forming a tool base having a diameter of 13 mm. WC-base cemented carbide tool bases (end mills) A-1 to A-10 having a size of 10 mm × 22 mm in diameter × length and a four-blade square shape with a twist angle of 30 degrees were manufactured.

  Then, the surfaces of these tool bases (end mills) A-1 to A-10 were ultrasonically cleaned in acetone and dried, and then charged into the arc ion plating apparatus shown in FIG. Under the same conditions as in Example 1, the target composition and the target layer thickness (Al, Ti) N thin layer shown in Table 15 and the target composition and the target layer thickness (Zr, V) shown in Table 15 are also shown. By forming a hard coating layer composed of an alternately laminated structure of N thin layers by vapor deposition, surface-coated carbide end mills (hereinafter referred to as the present invention-coated end mills) 16 to 30 of the present invention as the coated tools of the present invention were produced. .

  For comparison purposes, the surfaces of the tool bases (end mills) A-1 to A-10 are ultrasonically cleaned in acetone and dried, and then loaded into the arc ion plating apparatus shown in FIG. Then, under the same conditions as in Example 1, the (Al, Ti) N layer having the target composition and the target layer thickness shown in Table 16 and the (Zr, V) N layer having the target composition and the target layer thickness are shown in Table 16. By vapor-depositing the constituted hard coating layer, surface coated carbide end mills (hereinafter referred to as comparative coated end mills) 9 to 16 as comparative coated tools were produced, respectively.

Next, for the coated end mills 16 to 30 and the comparative coated end mills 9 to 16 of the present invention,
Work material-planar dimensions: 100 mm × 250 mm, thickness: 50 mm JIS / SUS304 (HB240) plate material,
Cutting speed: 100 m / min. ,
Groove depth (cut): 15mm,
Table feed: 320mm / min,
Wet high-speed grooving test of stainless steel under the following conditions (cutting condition d) (normal cutting speed and table feed are 80 m / min, 280 mm / min, respectively),
Work material—planar dimensions: 100 mm × 250 mm, thickness: 50 mm Ti-6Al-4V (HB290) plate,
Cutting speed: 65 m / min. ,
Groove depth (cut): 15mm,
Table feed: 100mm / min,
Wet high-speed grooving test of Ti alloy under the following conditions (cutting condition e) (normal cutting speed and table feed are 30 m / min. And 80 mm / min, respectively),
Work material-Plane dimensions: 100 mm x 250 mm, thickness: 50 mm JIS S45C (HB240) plate material,
Cutting speed: 230 m / min. ,
Groove depth (cut): 15mm,
Table feed: 600mm / min,
Wet high-speed grooving test of carbon steel under the following conditions (cutting condition f) (normal cutting speed and table feed are 190 m / min. And 500 mm / min, respectively)
In each high-speed groove cutting test, the cutting groove length was measured until the flank wear width of the outer peripheral edge of the cutting edge reached 0.1 mm, which is a guide for the service life. The measurement results are also shown in Table 15 and Table 16, respectively.

  Using the round bar sintered body with a diameter of 13 mm manufactured in Example 5, from this round bar sintered body, the diameter x length of the groove forming portion is 8 mm x 22 mm and twisted by grinding. WC base cemented carbide tool bases (drills) A-1 to A-10 having a two-blade shape with a 30-degree angle were manufactured.

  Next, the cutting edges of these tool bases (drills) A-1 to A-10 are subjected to honing, ultrasonically cleaned in acetone, and dried to the arc ion plating apparatus shown in FIG. Under the same conditions as in Example 4, the target composition shown in Table 17 and the (Al, Ti) N thin layer having a further target layer thickness and the target composition and target layer thickness shown in Table 17 are also shown. The surface-coated carbide drill of the present invention (hereinafter referred to as the present invention-coated drill) 16 as a coated tool of the present invention is formed by vapor-depositing a hard coating layer composed of an alternately laminated structure of (Zr, V) N thin layers of ˜30 were produced respectively.

  For the purpose of comparison, honing is performed on the surfaces of the tool bases (drills) A-1 to A-10, ultrasonic cleaning is performed in acetone, and the arc ion plate shown in FIG. The (Al, Ti) N layer having the target composition and the further target layer thickness shown in Table 18, and the target composition and the target layer thickness (Zr) under the same conditions as in Example 4 were charged. , V) Surface-coated carbide drills (hereinafter referred to as comparative coated drills) 9 to 16 as comparative coated tools were manufactured by vapor-depositing a hard coating layer composed of an N layer, respectively.

Next, for the inventive coated drills 16-30 and comparative coated drills 9-16,
Work material-planar dimensions: 100 mm × 250 mm, thickness: 50 mm JIS / SUS304 (HB240) plate material,
Cutting speed: 90 m / min. ,
Feed: 0.25 mm / rev. ,
Hole depth: 5mm,
Wet high-speed drilling test of stainless steel under the following conditions (cutting condition g) (normal cutting speed and feed are 60 m / min. And 0.2 mm / rev., Respectively),
Work material-planar dimensions: 100 mm x 250 mm, thickness: 50 mm Ti-6Al-4V alloy (HB290) plate material,
Cutting speed: 55 m / min. ,
Feed: 0.25 mm / rev. ,
Hole depth: 5mm,
Wet high-speed drilling test of Ti alloy under the following conditions (cutting condition h) (normal cutting speed and feed are 30 m / min. And 0.1 mm / rev., Respectively),
Work material-Plane dimensions: 100 mm x 250 mm, thickness: 50 mm JIS S45C (HB240) plate material,
Cutting speed: 150 m / min. ,
Feed: 0.3 mm / rev. ,
Hole depth: 5mm,
Wet high-speed drilling test of carbon steel under the following conditions (cutting condition i) (normal cutting speed and feed are 100 m / min. And 0.2 mm / rev., Respectively),
In each wet high-speed drilling test (using water-soluble cutting oil), the number of drilling processes until the flank wear width of the tip cutting edge surface reached 0.3 mm was measured. The measurement results are also shown in Table 17 and Table 18, respectively.

  (Al, Ti) N thin layer constituting the hard coating layer of the present coated insert 17-32, the present coated end mill 16-30, and the present coated drill 16-30 as the present coated tool obtained as a result. And the composition of the (Zr, V) N thin layer, and the (Al, Ti) N layer of the comparative coating inserts 9 to 16, the comparative coating end mills 9 to 16, and the comparative coating drills 9 to 16 as comparative coating tools When the composition of the hard coating layer was measured by energy dispersive X-ray analysis using a transmission electron microscope, it showed substantially the same composition as the target composition.

  Moreover, when the average layer thickness of each layer which comprises the said hard coating layer was cross-sectional measured using the scanning electron microscope, all showed the average value (average value of five places) substantially the same as target layer thickness.

  From the results shown in Tables 11 to 18, the coated tool of the present invention is a high-speed cutting process that is accompanied by a large heat generation and a high load, especially for difficult-to-cut materials such as titanium alloy steel, heat-resistant alloy steel, and stainless steel. However, the (Al, Ti) N thin layers that make up the alternating laminated structure of hard coating layers have excellent high-temperature hardness, high-temperature strength, and in addition to this, excellent wear resistance and high-temperature oxidation resistance. In addition, the (Zr, V) N thin layer, which also constitutes an alternately laminated structure, has excellent impact resistance and lubricity, and maintains excellent welding resistance between the work material and chips even under high temperature conditions. As a result, the welding resistance, which is insufficient for the (Al, Ti) N thin layer, is complemented by the (Zr, V) N thin layers alternately stacked on the thin layer, so that the entire hard coating layer is chipped. No wear and excellent wear resistance over a long period of time On the other hand, in the comparative coated tool in which the hard coating layer is composed only of the (Al, Ti) N layer and does not include the (Zr, V) N thin layer, both are high-speed cutting of the work material. Since the adhesiveness and reactivity between the work material (difficult-to-cut material) and chips and the hard coating layer are further increased, chipping occurs at the cutting edge, and the service life is shortened in a relatively short time. It is clear that

  As described above, the coated tool of the present invention has excellent wear resistance and resistance not only to cutting general work materials but also to high-speed cutting of difficult-to-cut materials such as stainless steel and heat-resistant steel. Since it exhibits weldability and exhibits excellent cutting performance over a long period of time, it can be used satisfactorily to meet FA requirements for cutting equipment, labor saving and energy saving, and cost reduction. is there.

Claims (2)

In a surface-coated cutting tool formed by forming a hard coating layer on the surface of a tool base composed of tungsten carbide-based cemented carbide or titanium carbonitride-based cermet,
The hard coating layer is
(A) having an average layer thickness of 0.5-5 μm, and
Composition formula: (Al _1-x Ti _x ) N (where x represents the content ratio of Ti in the total amount of Al and Ti, and the atomic ratio is 0.30 ≦ x ≦ 0.75) A lower layer composed of a satisfactory nitride layer of Al and Ti;
(B) having an average layer thickness of 0.5-5 μm, and
Composition formula: (Zr _1-a V _a ) N (where a represents the content ratio of V in the total amount of Zr and V, and the atomic ratio is 0.01 ≦ a ≦ 0.30) A surface-coated cutting tool comprising a satisfactory upper layer made of a composite nitride layer of Zr and V. In a surface-coated cutting tool formed by forming a hard coating layer on the surface of a tool base composed of tungsten carbide-based cemented carbide or titanium carbonitride-based cermet,
The hard coating layer is
(A) having an average layer thickness of 0.01 to 0.1 μm, and
Composition formula: (Al _1-x Ti _x ) N (where x represents the content ratio of Ti in the total amount of Al and Ti, and the atomic ratio is 0.30 ≦ x ≦ 0.75) (Al, Ti) N thin layer consisting of a satisfactory nitride layer of Al and Ti,
(B) having an average layer thickness of 0.01 to 0.1 μm, and
Composition formula: (Zr _1-a V _a ) N (where a represents the content ratio of V in the total amount of Zr and V, and the atomic ratio is 0.01 ≦ a ≦ 0.30) A (Zr, V) N thin layer consisting of a satisfactory composite layer of Zr and V,
A surface-coated cutting tool comprising the alternating lamination of (a) and (b) and having a total average layer thickness of 1 to 5 μm.