JP2005288582A - Covering member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a covering member having excellent lubricativeness to allow prolongation of the lifetime of machining tips, a machining tool such as drill, end mill, etc., and an anti-abrasive tool used in high-temperature environment and also sliding components and so on which are used under severe machining conditions such as in dry type machining, high-speed machining, etc. <P>SOLUTION: The covering member formed by putting a coating film on the surface of a base material to serve as a lubricating film in which at least one layer of the coating film consists of at least one of the elements belonging to the groups 1a and 2a according to the Periodic Table, at least one of the elements belonging to the group 7b according to the Periodic Table, and oxygen, has excellent lubricativeness. Therefore, this can prolong the lifetime of the machining tips used under severe machining conditions such as in dry type machining, high-speed machining, etc., machining tool such as drill, end mill, etc., and an anti-abrasive tool used in a high-temperature environment and also sliding components and so on. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a covering member used for cutting tools such as cutting tips, drills, and end mills, wear resistant tools, sliding parts, and the like.

A covering member coated with a hard film such as TiN, TiCN, TiC, (TiAl) N, or Al ₂ O ₃ is used for a cutting tool, an abrasion resistant tool, or a sliding part, and contributes to extending the life of these members. However, under dry conditions in which no cutting oil or lubricating oil is used, there is a problem that it is difficult to extend the life because the hard film is peeled off or oxidized due to the generation of stress and heat accompanying friction. Therefore, there is a covering member that coats a lubricating film to reduce the coefficient of friction and provide lubricity and welding resistance to extend the life. As a conventional technique of a covering member coated with a lubricating film, there is a covering member in which a base material surface is coated with a fluoride-containing film such as calcium fluoride (see, for example, Patent Document 1).

JP 2003-321863 A

A covering member in which a surface of a base material is coated with a fluoride-containing film such as calcium fluoride is excellent in lubricity at high temperatures, but has a problem that it is easy to wear and the finished surface quality of a work material is inferior. The present invention solves these problems, and cutting tools such as cutting tips, drills and end mills used under severe cutting conditions such as dry cutting and high-speed cutting, and wear-resistant tools used in high-temperature environments. An object of the present invention is to provide a covering member with excellent lubricity that extends the life of sliding parts and the like.

As a result of researches on coated members with excellent lubricity, the present inventor has excellent wear resistance when oxygen is contained in the halide film of the periodic table 1a and 2a elements coated on the surface of the base material. The knowledge that gloss was obtained on the finished surface of the work material when used as a cutting tool was obtained.

That is, according to the present invention, in the covering member in which the surface of the base material is coated, at least one layer of the coating includes at least one selected from the periodic table 1a and 2a group elements and the periodic table 7b group. It is a covering member which is a lubricating film comprising at least one selected from elements and oxygen.

The lubricating film of the covering member of the present invention comprises oxygen and at least one selected from Group 1a and 2a elements of the periodic table, at least one selected from Group 7b of the periodic table, and oxygen. Although the halides of Group 1a and 2a elements of the periodic table are excellent in lubricity, the addition of oxygen to these halides can improve the wear resistance without reducing the lubricity. Addition of oxygen also has an effect of improving the chipping resistance by refining the lubricating film crystal. When the coated member of the present invention is used as a cutting tool, gloss is seen on the finished surface of the work material. This is presumably because the surface of the work material and the lubricating film react or the periodic table 1a and 2a elements contained in the lubricating film diffuse into the work material surface to improve the free-cutting property of the work material. Specific examples of the lubricating film of the present invention include Li (F _0.9 , O _0.1 ) _0.9 , Ca (F _0.9 , O _0.1 ) _1.9 , Mg (F _0.9 , O _0.1 ) _{1.9, and the} like. Among the lubricating films of the present invention, a lubricating film comprising two or more selected from the halides of the periodic table 1a and group 2a elements, one or more selected from the group 7b elements of the periodic table, and oxygen Is preferable because of its excellent adhesion to the substrate or the base film. The average film thickness of the lubricating film is preferably 0.05 to 5 μm. This is because if it is less than 0.05 μm, the effect of improving the lubricity is small, and if it exceeds 5 μm, it is easy to peel.

When the lubricating film of the coated member of the present invention is represented as A (Ha _x , O _y ) _z , A represents at least one selected from the periodic table 1a and 2a group elements, and Ha represents the periodic table 7b. Represents at least one selected from group elements, O represents oxygen, x represents the atomic ratio of group 7b elements of the periodic table to the sum of group 7b elements and oxygen, and y represents the periodic table 7a represents the atomic ratio of oxygen to the total of group 7b elements and oxygen, z represents the atomic ratio of the total of group 7b elements and oxygen to periodic table 1a, 2a group elements, and x, y, z represent X + y = 1, 0.80 ≦ x ≦ 0.95, 0.05 ≦ y ≦ 0.20, 0.8 ≦ z ≦ 2.0 are satisfied. When y is 0.05 or more, the effect of improving the wear resistance by adding oxygen is seen. However, when y exceeds 0.20, voids (voids) are generated in the lubricating film and the wear resistance is lowered. When z is less than 0.8, the crystal component is greatly deviated from the stoichiometric composition ratio of the metal component (A) and the non-metal components (Ha and O), and the wear resistance is decreased. It is practically difficult to produce a film exceeding 0. In addition, when A has the periodic table group 1a as the main component, 0.8 ≦ z ≦ 1.0 is preferable, and when A has the periodic table group 2a as the main component, 1.6 ≦ z ≦ 2. 0 is preferred.

The lubricating film of the coated member of the present invention is a cubic lubricating film made of cubic crystals, and the half width of the X-ray diffraction peak of the (200) plane of the cubic lubricating film in the X-ray diffraction measurement is 0.4 to 1. .8 degrees is preferable. If the lubricating film is a cubic lubricating film composed of cubic crystals, the hardness is high and the wear resistance is excellent. Increasing the oxygen content of the lubricating film increases the half width. When oxygen is added so that the half width is 0.4 degrees or more, wear resistance is improved, and when oxygen is added so that the half width exceeds 1.8 degrees, voids are generated in the lubricating film. Reduces wear resistance.

At least one layer of the coating of the covering member of the present invention is at least one selected from the group 4a, 5a and 6a elements of the periodic table, aluminum, silicon carbide, nitride, oxide, boride, and their mutual solid solutions. A hard film made of seeds is preferable because it can increase wear resistance. Specifically, as the hard film, TiC, TiN, Ti (C, N), Ti (C, N, O), (Ti, Al) N, (Ti, Al) (C, N), (Ti, Al ) (C, N, O), (Ti, Si) N, (Cr, Si) N, ZrN, HfN, VN, Al ₂ O ₃ , ZrO _{2 and the} like. If the inner layer close to the substrate is a hard film and the outer layer on the surface side is a lubricating film, it is more preferable because the wear resistance of the film is improved. When the average thickness of the hard film is less than 1 μm, the effect of improving the wear resistance is small, and conversely, when the thickness exceeds 20 μm, the coating is easily peeled off and the strength of the covering member is reduced. Therefore, the average film thickness of the hard film is preferably 1 to 20 μm. Further, the hard film in contact with the lubricating film has a face-centered cubic structure and has a face-centered cubic structure with respect to the X-ray diffraction intensity Ih (111) of the (111) plane of the hard film having the face-centered cubic structure in the X-ray diffraction measurement. When the intensity ratio (Ih (200) / Ih (111)) of the X-ray diffraction intensity Ih (200) of the (200) plane of the hard film is 2 or more and practically 2 to 30, the hard film and the lubricating film This is particularly preferable because of high adhesion.

The substrate of the coated member of the present invention is not particularly limited, but for applications in which wear resistance is important, WC-Co-based, WC- (W, Ti, Ta) C-Co-based, which has excellent wear resistance, cemented carbide represented by WC-TaC-Co based, TiC-Mo-Ni system, cermet such as TiCN-WC-TaC-Ni- Co -based, Al ₂ O ₃ system, Al ₂ O ₃ -TiC based, Si Ceramics such as ₃ N ₄ series, cubic boron nitride sintered body, high speed steel and tool steel are preferred.

As one of the uses of the covering member of the present invention, cutting tools represented by cutting tips, drills, end mills, wear resistant tools, sliding parts and the like can be mentioned. Among these, it is particularly preferable to use the coated member of the present invention as a cutting tool because it exhibits excellent lubricity. It is very preferable when used for cutting a sintered alloy.

When the coated member of the present invention is used as a cutting tool, the average film thickness of the lubricating film on the rake face 1 mm away from the cutting edge of the cutting tool is represented by dr, and on the flank 1 mm away from the cutting edge of the cutting tool. When the average film thickness of the lubricating film is expressed as df, the film thickness ratio of df to dr (df / dr) is preferably 0.05 to 20. When (df / dr) is less than 0.05 or (df / dr) exceeds 20, the wear of the coating proceeds on the rake face having a small film thickness or the flank face having a thin film thickness during the cutting process, so This is because welding and chipping are remarkably caused by wear with a lack of balance between the surface and the rake face.

As a manufacturing method of this invention covering member, the method of coat | covering a lubricating film with a physical vapor deposition method or a chemical vapor deposition method can be mentioned, for example. Specifically, as a method of coating a lubricating film by physical vapor deposition, an unbalanced magnetron apparatus is used to target a metal compound represented by A (Ha _x , O _y ) _z , and a direct current pulse voltage, high frequency voltage or a method for coating a lubricant film by applying a microwave voltage, or to target a metal compound represented by AHa _z, while supplying oxygen gas, DC pulse voltage to the target, a high frequency voltage or microwave voltage, And a method of coating the lubricating film by applying. In the case where a hard film is coated as an inner layer and a lubricating film is coated on an outer layer, it is preferable to form the film by a continuous process because adhesion is improved. Specifically, as an apparatus for forming a film in a continuous process, a coating apparatus having both an arc type ion plating apparatus for forming a hard film in a vacuum chamber and an unbalanced magnetron apparatus for forming a lubricating film Can be mentioned.

The coated member of the present invention is excellent in lubricity and wear resistance. When the coated member of the present invention is used as a cutting tool, the lubricity and wear resistance are hardly lowered even during high-speed machining, and a glossy finished surface of the work material can be obtained.

A commercially available solid drill (φ 8.0 mm, equivalent to P30, composition: WC-8 wt% Co-10 wt% (Ta, Ti) C, hardness: HRA = 91.5) was prepared as a base material. In order to coat the hard film and the lubricating film of the present invention, the target 1 of the unbalanced magnetron method equipped with the arc-type ion plating method target 2 covering the hard film and the lubricating film of the present invention is provided. A composite PVD apparatus equipped with a pole was prepared.

The base material drill was first degreased and cleaned after removing scales and dirt with a brush as a pretreatment. This drill was fixed to a clean jig, inserted into a composite PVD apparatus, preliminarily evacuated to 1 × 10 ⁻³ Pa, and heated to 500 ° C. in a vacuum to remove water adhering to the surface. Further, Ar gas was introduced up to 1 Pa, and a bias voltage of −600 V was applied to the drill and held for 30 minutes, whereby the drill was sputter etched to clean the surface. Subsequently, the present invention products 1 to 3 and the comparative product 1 are sequentially coated with a hard film on the inner layer and a lubricating film on the outer layer under the coating conditions (gas component and flow rate, bias voltage, treatment time) shown in Table 1. ~ 3 drills were obtained.

When the outer layer lubricating films of the present invention products 1 to 3 and comparative products 1 to 3 are expressed as A (Ha _x , O _y ) _z (where x + y = 1), the periodic table is expressed by EDX (X-ray energy dispersion method). The atomic ratio y of oxygen with respect to the sum of the 7b group element (halogen element) and oxygen, and the atomic ratio z of the nonmetallic component (periodic table 7b group element and oxygen) with respect to the metal component (periodic table 1a, 2a group element) The values are shown in Table 2. Furthermore, about this invention products 1-3 and comparative products 1-3, the average film thickness d of the hard film | membrane and lubricating film in the rake face 1 mm away from the cutting edge ridgeline was measured. In addition, the film thickness ratio dr (dr / dr) was determined by measuring the film thickness dr of the lubricating film on the rake face 1 mm away from the cutting edge ridge line and the film thickness df of the lubricating film on the flank face. Furthermore, X-ray diffraction measurement using CuKα rays was performed, and the half width (degree) of the cubic (200) plane (2θ: 44 to 46 degrees) of the lubricating film was measured. Subsequently, the X-ray diffraction intensity Ih (200) of the cubic (200) plane of the hard film and the X-ray diffraction intensity Ih (111) of the cubic (111) plane were measured, respectively, and the intensity ratio (Ih (200) / Ih (111)). These values are listed in Table 2.

Using the drills of the present invention products 1 to 3 and comparative products 1 to 3, drilling was performed under the conditions of work material: S45C, cutting peripheral speed: 100 m / min, hole depth: 50 mm, and dry machining. It went continuously. Table 3 shows the number of holes that can be processed until a sharp torque increase occurs due to chipping, breakage, or chip clogging. When it was normal up to 200 holes, the average flank wear amount of the cutting edge was also shown.

Inventive products 1 to 3 having an oxygen atomic ratio y of 0.02 to 0.06 have 3 to 13 times more holes that can be processed than comparative products 1 to 3.

Claims (7)

In the covering member in which the surface of the substrate is coated, at least one layer of the coating is selected from at least one selected from the elements of Group 1a and 2a of the periodic table and from element 7b of the periodic table. A covering member which is a lubricating film comprising at least one kind and oxygen. The lubricating film is represented as A (Ha _x , O _y ) _z , A represents at least one selected from Group 1a and 2a elements of Periodic Table, and Ha represents Group 7b of Periodic Table Represents at least one selected, O represents oxygen, x represents the atomic ratio of the periodic table group 7b element to the sum of the periodic table group 7b element and oxygen, and y represents the periodic table group 7b element and oxygen. Represents the atomic ratio of oxygen to the sum of the elements, z represents the atomic ratio of the elements of the periodic table group 7b to the periodic table 1a, 2a group elements and oxygen, and x, y, z are x + y = 1, The covering member according to claim 1, wherein 0.80≤x≤0.95, 0.05≤y≤0.20, and 0.8≤z≤2.0 are satisfied. The lubricating film is a cubic lubricating film, and the half width of the X-ray diffraction peak of the (200) plane of the cubic lubricating film in the X-ray diffraction measurement is 0.4 to 1.8 degrees. The covering member according to 2. At least one layer of the film is a hard film composed of at least one selected from the group consisting of elements 4a, 5a and 6a of the periodic table, aluminum, silicon carbide, nitride, oxide, boride and their mutual solid solutions The covering member according to any one of claims 1 to 3. The coating according to any one of claims 1 to 4, wherein the base material is one selected from cemented carbide, cermet, ceramics, cubic boron nitride sintered body, high-speed steel, and tool steel. Element. The covering member according to claim 1, wherein the covering member is used as a cutting tool. When the average film thickness of the lubricating film on the rake face 1 mm away from the cutting edge of the cutting tool is represented by dr, and the average film thickness of the lubricating film on the flank 1 mm away from the cutting edge of the cutting tool is represented by df, The covering member according to claim 6, wherein a film thickness ratio (df / dr) of df to dr is 0.05 to 20.