JP5348223B2 - Covering member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coating member achieving long life in a strict cutting work condition such as increase of hardness of cutting object material. <P>SOLUTION: This coating member comprises a base material and a coating film deposited on the surface of the base material. In the coating member, at least one layer of the coating film is a hard film represented by (M<SB POS="POST">A</SB>L<SB POS="POST">D</SB>)X<SB POS="POST">R</SB>deposited by a PVD method, where M is two or more kinds of metal elements selected from Cr, Al, Ti, Hf, V, Zr, Ta, Mo, W, Y and Nb; L is at least one kind of added element selected from Mn, Cu, Ni, Co, B, Si and S; X is at least one kind of non-metal element selected from C, N and O; A is an atom ratio of M to the sum of M and L; D is an atom ratio of L to the sum of M and L; R is an atom ratio of X to the sum of M and L; and 0.90&le;A&le;0.99, 0.01&le;D&le;0.10, A+D=1, and 0.95&le;R&le;1.10 are satisfied; and the hard film shows the highest peak intensity in X-ray diffraction on the (220) plane. <P>COPYRIGHT: (C)2012,JPO&amp;INPIT

Description

  The present invention relates to a covering member in which a surface of a base material such as a sintered alloy, ceramics, cBN sintered body, diamond sintered body, etc. is coated. In particular, the present invention relates to a covering member suitable for a cutting tool represented by a tip, a drill, an end mill, various wear-resistant tools, and wear-resistant parts.

The surface of a base material such as a sintered alloy, ceramics, cBN sintered body, diamond sintered body, etc. is coated with a coating such as TiC, TiCN, TiN, (Ti, Al) N, Al ₂ O ₃ by the PVD method. The coated member combines the high strength and high toughness of the base material with the excellent wear resistance, oxidation resistance, lubricity, and welding resistance of the coating. It is used a lot. In order to improve these performances, the hardness and oxidation resistance of the coating have been improved.

As a conventional technique of a hard film coated by the PVD method, there is a hard film for a cutting tool made of (Ti, Al, Cr) (C, N) (for example, see Patent Document 1). Moreover, as a film excellent in oxidation resistance, there is an Al—Cr—N-based film. However, due to changes in the work material, cutting conditions, etc., there has been a problem that a long tool life cannot be obtained with a cutting tool coated with these films.

JP 2003-71610 A

  In recent years, severe machining conditions such as high speed, high feed, and high hardness of the work material are increasing in cutting. A cutting tool made of a conventional covering member cannot meet the recent severe processing demands. This invention is made | formed in view of such a situation, and it aims at provision of the coating | coated member which implement | achieves lifetime improvement in cutting.

  Cubic hard films such as (TiAl) N, (CrAl) N, and (TiAlCr) N coated by the conventional PVD method are oriented in the (111) plane or the (200) plane. The inventor has been working on improving the cutting performance of a coated member coated with a cubic hard film such as (TiAlSi) N, (CrAlB) N, and (TiAlCrSi) N coated by the PVD method. It was found that by aligning the hard film in the (220) plane, the hardness was increased, the wear resistance at high temperature was improved, and the oxidation resistance was improved. It has been found that the coated member coated with the hard film of the present invention is excellent in wear resistance and oxidation resistance, so that it can realize a long life when used as a cutting tool.

The covering member according to claim 1 is composed of a base material and a coating film coated on the surface of the base material, and at least one layer of the coating film is (M _A L _D ) X _R (where M Represents two or more metal elements selected from Cr, Al, Ti, Hf, V, Zr, Ta, Mo, W, Y, and Nb, and L represents Mn, Cu, Ni, Co, B, and Si. , S represents at least one additive element selected from S, X represents at least one nonmetallic element selected from C, N, and O, and A represents the amount of M relative to the sum of M and L D represents the atomic ratio of L to the sum of M and L, R represents the atomic ratio of X to the sum of M and L, 0.90 ≦ A ≦ 0.99, 0.01 ≦ D ≦ 0.10, A + D = 1, 0.95 ≦ R ≦ 1.10), and the hard film is subject to X-ray diffraction. It shows the highest peak intensity in the (220) plane.

Examples of the base material of the covering member of the present invention include sintered alloys, ceramics, cBN sintered bodies, and diamond sintered bodies. Among these, sintered alloys are preferable because they are excellent in fracture resistance and wear resistance. Among them, cemented carbide and cermet are more preferable, and cemented carbide is more preferable.

At least one layer of the coating of the covering member according to claim 1, coated by PVD _{(M A L D) X R} ( where, M is Cr, Al, Ti, Hf, V, Zr, Ta, Mo, Represents two or more metal elements selected from W, Y, and Nb, L represents at least one additive element selected from Mn, Cu, Ni, Co, B, Si, and S; X represents at least one nonmetallic element selected from C, N, and O, A represents the atomic ratio of M to the total of M and L, and D represents the atomic ratio of L to the total of M and L R represents the atomic ratio of X to the sum of M and L, 0.90 ≦ A ≦ 0.99, 0.01 ≦ D ≦ 0.10, A + D = 1, 0.95 ≦ R ≦ 1. 10 is satisfied.) And is a hard film having a cubic NaCl type structure.

When A is less than 0.90, the wear resistance decreases, and when A exceeds 0.99, the oxidation resistance decreases. Therefore, A is set in the range of 0.90 ≦ A ≦ 0.99. When D is less than 0.01, the oxidation resistance decreases, and when D exceeds 0.10, the wear resistance decreases. Therefore, D is set in the range of 0.01 ≦ D ≦ 0.10. When R is less than 0.95, the amorphous metal phase segregates and the oxidation resistance and hardness decrease, and when R exceeds 1.10, the hardness of the coating rapidly decreases. .95 ≦ R ≦ 1.10. Specifically, as the hard film, ((TiAl) _0.95 B _0.05 ) N _1.00 , ((TiAl) _0.96 Mn _0.04 ) N _1.00 , ((TiAl) _0.97 S _0.03 ) N _1.00 , ((TiAl) _0.95 Si _0.05 ) N _1.00 , ((TiCr) _0.95 B _0.05 ) N _1.00 , ((CrAl) _0.97 B _0.03 ) N _1.06 , ((CrAl) _0.95 Si _0.05 ) N _1.00 , ((CrAl) _0.98 S _0.02 ) N _0.98 , ((CrAl) _0.90 Y _0.10 ) N _0.95 , ((CrZr) _0.96 B _0.04 ) N _1.07 , ((TiAlCr) _0.95 Si _0.05 ) N _1.00 , ((TiAlV) _0.95 Si _0.05 ) N _1.09 , ((TiAlZr) _0.95 Si _0.05 ) N _1.00 , ((CrAlZr) _0.90 B _0.10 ) N _1.09 , ((CrAlZr) _0.95 Si _0.05 ) N _1.00 , ((CrAlW) _0.95 S _0.05 ) N _1.00 , ((TiAlZrY) _0.90 B _0.10 ) N _{1.00, and the} like. . Among them, the hard film is more preferably a laminated film in which thin films having an average film thickness of 1 to 100 nm having different compositions are laminated because the hardness of the film is increased and the wear resistance is improved.

Since the hard film of the present invention exhibits the highest peak intensity in X-ray diffraction on the (220) plane, it is harder than conventional coatings, exhibits excellent wear resistance at high temperatures, and has excellent oxidation resistance. Indicates.

The film of the present invention is a single layer film made of only the hard film of the present invention, or carbide, nitride of Cr, Al, Ti, Hf, V, Zr, Ta, Mo, W, Nb, Y, Si, B And a multilayer film in which a film made of at least one selected from oxides and their mutual solid solutions and the hard film of the present invention are coated. Specific examples of the multilayered film together with the hard layer of the present invention include TiN, TiCN, TiC, Al ₂ O _{3 and the} like. Moreover, the film | membrane multilayered with the hard layer of this invention can be coat | covered by PVD method or CVD method. Among them, the PVD method is more preferable because it is continuously coated with the hard film of the present invention and has excellent adhesion between the films.

When the average film thickness of the coating film of the present invention is 0.5 μm or more, the wear resistance and oxidation resistance are improved, and when the average film thickness of the coating film of the present invention exceeds 15.0 μm, the chipping resistance decreases. Therefore, the average film thickness of the coating of the present invention is preferably in the range of 0.5 to 15.0 μm.

The composition of the film of the present invention can be measured using an elemental analyzer such as a secondary ion mass spectrometer (SIMS), an energy dispersive element analyzer (EDS), or a glow discharge analyzer (GDS).

The hard film of the present invention is coated by the PVD method. Since the covering member coated with the hard film of the present invention is excellent in fracture resistance, it is preferably used for a milling tool, drilling tool or the like that requires fracture resistance. Examples of the PVD method include an arc ion plating method and a sputtering method. Among these, the arc ion plating method which is excellent in the adhesion between the coating and the substrate is more preferable.

In a conventional arc ion plating apparatus (hereinafter referred to as AIP apparatus), when coating a film, the pressure in the furnace is set to 2.5 to 5.0 Pa, and arc discharge control is a constant current with a constant current value. I was doing control. The constant current control is a method of controlling the discharge current to be constant by changing the voltage when the discharge resistance in the furnace changes. On the other hand, the coating condition of the hard film of the present invention is a constant voltage in which the pressure in the furnace is 0.5 to 2.0 Pa, which is a higher vacuum side region than the conventional method, and the arc discharge control is constant voltage. Control and increased arc discharge voltage. That is, when the arc discharge is made constant at a high voltage and the pressure in the furnace is lowered, a hard film oriented in the (220) plane of the present invention can be obtained. When the arc discharge is set to a high voltage, the current value of the arc discharge increases, and the temperature of the base material and the AIP device increases. In that case, it is also preferable to use voltage control that combines pulse control that makes arc discharge intermittent and constant voltage control in order to prevent temperature rise.

Specifically, as the coating conditions of the hard film of the present invention using the AIP apparatus, after heating the substrate to 573 to 973 K, the pressure in the furnace: 0.5 to 2.0 Pa, the arc discharge voltage: DC modulation Examples of the coating condition include 30 to 150 V (constant voltage control) and a bias voltage of the substrate of −30 to −200 V.

  The covering member of the present invention is excellent in wear resistance and oxidation resistance. The covering member of the present invention realizes a long tool life. In particular, a long service life is achieved in cutting operations with severe processing conditions such as high-speed machining, high-feed machining, and machining of hard work materials.

An example of the X-ray diffraction measurement result of the covering member of the present invention Example of X-ray diffraction measurement result of conventional coated member

Example 1
A chip made of cemented carbide equivalent to K20 having a shape of SDKN1203AETN was prepared as a base material. The prepared base material is inserted into an AIP apparatus capable of mounting a 6-pole target including the metal bombardment electrode, and after evacuating to a pressure of 1 × 10 ⁻³ Pa, the AIP apparatus The substrate was heated to 773K with the heater inside. Metal bombardment was performed under the bombardment conditions of pressure: 1 × 10 ⁻² Pa, substrate bias potential: −600 V, arc current: 100 A, time: 6 minutes, and the inventive products 1 to 10 are films shown in Table 1. A coating of the composition was coated. For the coating, a target having a component ratio between the metal element and the additive element of each film was used, N ₂ was introduced as a reaction gas, pressure: 0.6 to 2.0 Pa, arc discharge voltage: DC modulation 30 to 70 V (constant) Voltage control), bias voltage of substrate: -30 to -80V. At this time, the inventive products 1 to 10 were repeatedly laminated with the first layer, the second layer, the third layer, and again the first layer, the second layer, and the third layer from the base material side.

In Comparative products 1 to 6, after the base material was put in an AIP apparatus and heated, and after metal bombardment was performed under the same conditions as Invention products 1 to 8, pressure: 3.0 Pa, arc current: 120 A (constant current control) The film having the film structure shown in Table 2 was coated under the coating condition of bias voltage of substrate: −30V. In addition, the comparative products 3-5 repeated the 1st layer, the 2nd layer, the 1st layer, and the 2nd layer again from the base material side, and laminated | stacked the thin film.

Using the X-ray diffractometer, the sample obtained was subjected to X-ray diffraction measurement at 2θ = 10 to 120 degrees with Cukα1 line, and it was confirmed that the film had a cubic NaCl structure. Was measured. The results are shown in Tables 3 and 4. The X-ray diffraction peak intensities of the coatings of Inventions 1 to 8 were highest on the (220) plane. The X-ray diffraction peak intensities of the coatings of Comparative products 1 to 6 were highest on the (111) plane or the (200) plane.

About the obtained sample, the hardness of the film in 50 gf of applied loads was measured using the Matsuzawa Seiki Co., Ltd. micro Vickers hardness meter. The obtained values are shown in Tables 3 and 4. It can be seen from Tables 3 and 4 that the inventive products 1 to 8 are higher in hardness than the comparative products 1 to 6.

Next, using the obtained sample, a dry milling test was performed under the conditions of a work material: SCM440, a cutting speed: 212 m / min, a notch: 2.0 mm, and a feed: 0.2 mm / tooth. The tool life was estimated based on the flank wear amount VB = 0.3 mm. When the flank wear amount VB did not reach 0.3 mm by the cutting length of 6 m, the flank wear amount VB at the cutting length of 6 m was measured. These results are shown in Table 5.

寿命判定：ＶＢ＝０．３ｍｍ

Life judgment: VB = 0.3mm

As shown in Table 5, invention products 1 to 8 have a smaller flank wear amount VB than comparative products 1 to 6 even at the same cutting length. This indicates excellent wear resistance. In addition, it can be seen from Table 5 that the inventive products 1 to 8 have a longer lifetime than the comparative products 1 to 6.

Commercially available molybdenum substrates were coated with the coatings of Inventions 1 to 3 and Comparatives 1 to 5. In order to evaluate the oxidation resistance of the coating, it was heated from 600 ° C. to 900 ° C. in the atmosphere, and the change in the crystal structure was examined by the X-ray diffraction method. The results are shown in Table 6.

As shown in Table 6, almost no change was observed up to 900 ° C. for the coatings of Inventions 1 to 3. On the other hand, the X-ray diffraction peak intensities of the coatings of Comparative products 1 to 5 decreased at 800 ° C. or higher, and X-ray diffraction peaks of oxides such as TiO ₂ , Cr ₂ O ₃ , and Al ₂ O ₃ were confirmed. It was.

Claims (4)

(M _A L _D ) X _R (where M is Cr, Al, Ti, Hf, V), which comprises a substrate and a coating coated on the surface of the substrate, and at least one layer of the coating is coated by the PVD method. , Zr, Ta, Mo, W, Y, Nb represents at least one metal element selected from the group consisting of Mn, Cu, Ni, Co, B, Si, and S. X represents at least one nonmetallic element selected from C, N, and O, A represents the atomic ratio of M to the sum of M and L, and D represents M and L Represents the atomic ratio of L to the sum of R, R represents the atomic ratio of X to the sum of M and L, 0.90 ≦ A ≦ 0.99, 0.01 ≦ D ≦ 0.10, A + D = 1, .95 ≦ R ≦ 1.10), and the hard film has a maximum peak intensity in X-ray diffraction of (220). Covering member shown in.   The covering member according to claim 1, wherein the hard film is a laminated film in which thin films having an average film thickness of 1 to 100 nm having different compositions are laminated.   The covering member according to claim 1 or 2, wherein an average film thickness of the coating is 0.1 µm to 15 µm.   The covering member according to any one of claims 1 to 3, wherein the hard film is coated by an arc ion plating method.

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