JP3358696B2 - High strength coating - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal, alloy or ceramics sintered body having a Ti and A
The present invention relates to a high-strength coating body coated with a coating of a compound containing l, specifically, a metal, alloy or ceramic sintered body coated with a coating having high hardness and high toughness, for example, turning. Cutting tools such as tools, milling tools, drills and end mills, cutting blades such as slitters, cutting blades and mold tools such as dies and punches, and wear-resistant tools such as corrosion-resistant wear-resistant members such as nozzles. And high-strength coverings most suitable for civil engineering construction tools represented by bits.

[0002]

2. Description of the Related Art Metal, alloy and ceramic substrates are coated with a ceramic coating having a thickness of 20 μm or less,
Numerous coating members have been proposed in order to effectively draw out the characteristics of the base and the coating to achieve a long life. The method of coating the coating on the coating member is roughly classified into a chemical vapor deposition method (CVD method) and a physical vapor deposition method (PVD method). Among them, a film coated by the PVD method has an advantage of increasing abrasion resistance without deteriorating the strength of the substrate. For this reason, coatings of coated cutting tools typified by drills, end mills, and throw-away inserts for milling, which generally emphasize strength and fracture resistance, are currently coated by a PVD method.

[0003] It is well known that a titanium nitride film is applied to improve wear resistance. However, metal nitrides typified by titanium nitride are liable to be oxidized at high temperatures, and have a problem that wear resistance is significantly deteriorated. In order to improve the problem of oxidation of the titanium nitride film, one proposed in the mid 1980's includes (Ti
There is a member related to a coating member represented by a film of (Al) N or (TiAl) (CN), representative examples of which are JP-A-62-56565 and JP-A-7-19.
No. 7235 is known. In addition, JP-A-4-128362 and JP-A-7-2049 disclose a coating of (TiAl) N with an intermediate layer of Ti metal interposed.
No. 07 publication.

[0004]

Japanese Patent Application Laid-Open Nos. 62-56565 and 7-197235, which are related arts relating to a coating of a TiAl compound, disclose carbides containing Ti and Al on the surface of a substrate, nitriding. It describes a surface-coated hard member having excellent wear resistance in which a hard coating layer composed of a single layer or two or more layers of one of a metal and a carbonitride is formed.

[0005] The surface-coated hard members described in the above two publications are:
Although it is a coated hard member with improved oxidation resistance and abrasion resistance compared to the Ti compound coating as in the beginning of development, it has the opposite effect on the adhesion between the substrate and the hard coating layer and the mechanical properties of the hard coating layer. This causes a problem that the cutting performance is deteriorated when applied to a tool, particularly a cutting tool used under severe conditions. In other words, the surface-coated hard members described in both publications achieve improved chemical properties of the coating surface as compared with the Ti compound coating by containing Al in the coating, but the fracture toughness value is reduced. That, the peel resistance is reduced, especially when used as a cutting tool for high-speed cutting,
Oxidation of the coating due to high temperature, rapid wear, deterioration due to thermal shock, and short life due to welding with the work material.

On the other hand, JP-A-4-128362 and JP-A-7-204907 disclose an intermediate layer of Ti metal and a hard coating layer made of a nitride containing Ti and Al on a substrate of an iron-based material. The present invention discloses a coated steel material coated with.

[0007] In the coated steel materials described in these publications, the crystal of the intermediate layer made of Ti metal is easily coarsened, and the surface thereof has irregularities. As a result, the intermediate layer and the nitride of Ti and Al are hardened. The adhesion to the coating layer is not as high as expected, and in severe applications such as cutting tools, there is a problem that peeling or chipping is liable to occur, resulting in a short life.

The present invention has solved the above-mentioned problems, and specifically, has high toughness, high hardness, abrasion resistance, and oxidation resistance in a wide range from a low temperature range to a high temperature range. It is an object of the present invention to provide a high-strength coating that has a longer life by being coated with a coating having heat resistance, thermal shock resistance, fracture resistance, welding resistance, and a peeling-resistant coating.

[0009]

Means for Solving the Problems The present inventors have found that a coated member in which a nitride film containing Ti and Al is coated on a cemented carbide substrate has an excellent effect when used in a low temperature region. While studying the problem that the effect is reduced when used in a high-temperature region, the substrate and T
There is a large cause for the adhesion to the nitride or carbonitride coating containing i and Al.
Adhesion is improved when an intermediate layer of an amorphous substance containing i or Ti is interposed, and an intermediate layer having a high amorphous ratio is obtained under a predetermined condition while it is difficult to form an amorphous film as a coating of this system. In addition, the content ratio of Ti and Al and the content ratio of nitrogen and carbon in the nitride or carbonitride coating containing Ti and Al not only greatly affect the properties of the coating, but also The present invention has been found to have a significant effect on the adhesion between the film and the film, and has completed the present invention.

[0010] The high-strength coating of the present invention comprises an intermediate layer containing 50% by volume or more of amorphous Ti or a Ti-containing amorphous substance on a base made of a metal material, a sintered alloy or a ceramic sintered body. (T
_{i a, Al 1-a)} C x N 1-x [ However, Ti in the formula is titanium,
Al represents aluminum, a represents the atomic ratio of Ti, and X represents the atomic ratio of carbon. Also, 0.45 ≦ a ≦ 0.54, 0 ≦ X
≦ 0.5] is covered with an outer layer made of a composite compound containing titanium and aluminum.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The substrate in the high-strength coating of the present invention is made of a metal member, a sintered alloy or a ceramic sintered body that can withstand the heating temperature when coating the coating. , For example, stainless steel, heat-resistant alloy,
Metal members represented by high-speed steel, die steel, Ti alloy, Al alloy, cemented carbide, cermet, sintered alloy composed of powdered high-speed steel, Al ₂ O ₃ sintered body, Si ₃ N ₄ sintered Examples of the sintered body include a sintered body made of a sintered body, a sialon-based sintered body, and a ZrO ₂ -based sintered body. Of these, when used as cutting tools or wear-resistant tools, cemented carbide,
A nitrogen-containing TiC cermet or a ceramic sintered body is preferable.

It is particularly preferable that these substrates are made of a cemented carbide having a good balance of strength, fracture toughness and hardness characteristics of the substrates themselves. Specifically, Co and / or Ni are the main components. The binding phase contained as 4-1
5% by weight, with the balance being tungsten carbide, or a cemented carbide of tungsten carbide and a hard phase of a cubic compound of carbides, carbonitrides of elements of groups 4a, 5a and 6a of the periodic table and their mutual solid solutions. Alloy.

Further, the cemented carbide as a particularly preferred substrate will be described in detail.
For example, Co, Ni, Co-Ni, or Cr,
Co-Cr, Co-Ni-C in which V, Zr and W are dissolved
r, Co-V, Co-Cr-V, Co-Cr-Zr, C
o-W-Cr. Also, the hard phase is
Specifically, for example, WC, WC and other (WTi) C,
(WTaTi) C, (WTaNbTi) C, TaC,
One containing at least one of the cubic compounds of (WTi) CN and (WTaTi) CN with respect to the hard phase in an amount of 20% by weight or less can be given.

The intermediate layer coated on the substrate is made of amorphous Ti or an amorphous substance containing Ti, for example, TiO _y [where y ≦ 2], Ti
Al, (TiAl ₂ ) O _z [however, it represents z ≦ 5] contains at least 50% by volume of at least one kind of amorphous substance, and the remainder is a crystalline substance, specifically, Ti, TiO, Ti
O ₂ , TiAl, Ti ₃ Al, TiAl ₃ , (TiAl ₂ )
It is made of a crystalline substance of O ₄ ,) and (TiAl ₂ ) O ₅ . The amorphous substance contained in the intermediate layer is 5
If the amount is less than 0% by volume, the peeling resistance is significantly reduced. This intermediate layer is particularly preferably made of an oxide containing an oxygen atom ratio of 40% or less with respect to the intermediate layer.

The purpose of this intermediate layer is to provide adhesion to a substrate and adhesion to an outer layer described later.
When one or more types of Ti, Ti oxide composed of microcrystals of nm or less are contained, the flattening and smoothing of the surface of the intermediate layer serving as an interface between the base and the outer layer are enhanced, and the effect of improving the adhesion is improved. This is particularly preferred because of the presence. The microcrystal having a diameter of 10 nm or less contained in the intermediate layer may be an amorphous substance or a crystalline substance. The layer thickness of the intermediate layer is 0.005 to 0.5 because it is intended for adhesion.
It is particularly preferred that the thickness be 5 μm.

The outer layer coated on the surface of the intermediate layer is
(Ti _a , Al _1-a ) C _x N _1-x [where Ti is titanium, Al is aluminum, a is the atomic ratio of Ti, and x is the atomic ratio of carbon. Also, 0.45 ≦ a ≦ 0.7, 0
.Ltoreq.x.ltoreq.0.5] and a composite compound containing titanium and aluminum. This outer layer, when formed of a single layer or two or more layers, more one layer gradient composition in a single layer or multi-layer, specifically, for example, _{(Ti a, Al 1-a} ) C x N 1 _The composition may be such that the content of at least one of the elements in the _-x composition varies from the surface of the outer layer toward the interface with the intermediate layer. The layer thickness of this outer layer is 0.45 to 0.55 from peeling resistance and abrasion resistance.
It is particularly preferred that the thickness be 9.5 μm.

The total film thickness of the intermediate layer and the outer layer coated on the surface of the substrate is 20 μm or less, which is the film thickness conventionally used as a tool cover by chemical vapor deposition and physical vapor deposition. The thickness is preferably 0.5 to 10 μm from the viewpoint of peeling resistance and abrasion resistance, and it is particularly preferable to select the thickness of the coating according to the application and shape. For example, it is suitable for cutting tools for end mills, drills and milling. When used, it is preferable to reduce the coating thickness,
Specifically, for example, the total thickness is preferably 0.5 to 5 μm.

In the case of a substrate made of a cemented carbide or a sintered cermet alloy among the above-mentioned substrates, a carbide containing Co and W or a Ti and W is contained between the substrate and the intermediate layer. It is preferable to form a single layer of a solid solution or an inner layer composed of two or more types of layers because wear resistance and plastic deformation resistance can be improved. Specifically, this inner layer is made of, for example, Co ₃ W ₉ C ₄ , Co ₂ W ₄ C, C
o ₃ W ₃ C, Co ₆ W ₆ C, (CoNi) ₂ W ₄ C carbides,
Alternatively, a solid solution of (TiW) C, (TiW) N, and (TiW) CN may be a single solution or a mixture of two or more layers.

In the case of a coating in which an inner layer, an intermediate layer, and an outer layer are sequentially formed on a substrate made of a sintered alloy, the total thickness of these layers is 0.5 to 0.5 from the viewpoint of peeling resistance and abrasion resistance. 10
It is preferable that the thickness of the coating be selected depending on the application and shape as in the case of the above-described film configuration. For example, when the coating is used for a cutting tool for an end mill, drill, or milling, the coating thickness should be reduced. More specifically, for example, the total thickness is preferably 0.5 to 5 μm. The inner layer at this time has a layer thickness of 0.
It is preferably from 005 to 1.5 μm.

The high-strength coating of the present invention can be used for a metal member represented by stainless steel, a heat-resistant alloy, a high-speed steel, a die steel, a Ti alloy, an Al alloy, a cemented carbide, a cermet, and the like. , Sintered alloy of powdered high-speed steel, Al ₂ O ₃ based sintered body, Si ₃ N ₄ based sintered body, Sialon based sintered body, ZrO
A cemented carbide equivalent to P20 to P40, M20 to 40 and K10 to K20, which is based on a ceramic sintered body of the ₂ series sintered body and is preferably classified in the selection criteria for the use of cemented carbide according to JIS B4053 Material, particularly preferably P
A substrate made of a cemented carbide material equivalent to 30, M20 or M30 may be used. The surface of the substrate is polished, if necessary, and subjected to ultrasonic treatment, cleaning treatment with an organic solvent, or the like, and thereafter, a conventional physical vapor deposition method (PVD method), chemical vapor deposition method (CVD method) or It can be manufactured by coating a film on a substrate by a plasma CVD method.

When a film is coated on the substrate, the film may be coated according to the quality of each film, including the inner layer to be coated if necessary.
The VD method, the CVD method, or the plasma CVD method can be properly used. Of these, from the viewpoint of the manufacturing process, it is preferable that all the coatings of the inner layer, the intermediate layer, and the outer layer are performed by a PVD method typified by an ion plating method or a sputtering method. Among them, an ion plating method, particularly an arc ion plating method is preferred. -It is preferable to carry out a coating treatment by a coating method. When the base is made of a cemented carbide and the inner layer is made of a carbide containing Co and W, the carbon content in the raw material powder used to produce the cemented carbide is adjusted to a low carbon region. In addition, the inner layer can be formed from the element of the raw material powder during the sintering process, or the inner layer can be formed from the element of the raw material powder in a decarburizing atmosphere before coating the intermediate layer after sintering. .

The intermediate layer in the high-strength coating of the present invention is produced, for example, by ionizing Ti metal at a high voltage and colliding with a substrate in the case of production by the PVD method. A high-amorphous intermediate layer is formed by bombarding high-energy Ti ions against the surface of a substrate held at a high temperature, or bombarding high-energy Ti ions against a similar substrate surface in an atmosphere containing oxygen. Is done. More specifically, in this regard, the temperature of the substrate is lowered to, for example, 400 ° C. or less, and the gas pressure in the reactor for forming the intermediate layer is increased to 30 × 10 ⁻⁶ Torr or more. is there.

The outer layer of the high-strength coating of the present invention is prepared, for example, by PVD, using titanium, metal aluminum, or an alloy containing the elements Ti and Al as the metal source. When the metal source is ionized, glow discharge or high-frequency heating may be used in addition to arc discharge. The atmosphere gas is, for example, nitrogen for forming a nitride. In addition to the gas, a compound gas such as ammonia containing nitrogen may be used. It is preferable to introduce this reaction gas into a furnace, ionize a metal or alloy as a metal source, and apply a negative bias to the substrate to synthesize a coating.

[0024]

In the high-strength coating of the present invention, the surface of the intermediate layer is made highly amorphous, so that a surface having high flatness and smoothness is formed. As a result, the interface between the intermediate layer and the base and the intermediate layer and the outer layer are formed. That the adhesion at the interface with the substrate is strengthened, and that it acts to relieve the stress remaining near the interface between the substrate and the coating, especially in the case of a substrate made of cemented carbide. It acts to enhance the adhesion, and all of these actions achieve excellent properties throughout the coating.

[0025]

Example 1 Commercially available shape SNGN120408
Cemented carbide (material equivalent to P30 of JIS B4053)
After cleaning the surface of the substrate with an organic solvent, the substrate is placed in a chamber of the arc discharge plasma method (installed using a jig capable of simultaneously covering the flank face and the rake face), and the inside of the chamber is 1.0 × 10 ^{-5 to} 3.0 × 10 ^-6 Torr
Vacuum. Next, the inside of the chamber was maintained at the gas pressure shown in Table 1, and each substrate was heated to the temperature shown in Table 1 to form an intermediate layer. After forming the intermediate layer, a target made of a Ti-Al alloy was discharged for about 30 minutes under the conditions shown in Table 2 to form an outer layer on the surface of the intermediate layer.
5 and Comparative products 1 to 3 were obtained.

Further, the raw material powder WC,
80% WC using (TiTaW) C and Co
A cemented carbide having a composition of -10% (TiTaW) C-10% Co was prepared, and the cemented carbide was used as a base. Further, except for the formation of the intermediate layer, the other parts were treated in the same manner as the comparative product 1, and the outer layer was formed directly on the surface of the substrate to obtain a comparative product 4.

The coatings of each of the products 1 to 6 of the present invention and the comparative products 1 to 4 thus obtained were examined by an X-ray diffractometer, an electron microscope and an EDX device, and the intermediate layer was an amorphous substance containing Ti and oxygen. That the outer layer is (Ti, A
1) It was confirmed to be composed of a compound. In addition, the present invention products 1 to
6 and Comparative Examples 1-4 were analyzed with an X-ray diffractometer and a glow discharge optical emission spectrometer, and the thickness of each coating was examined with a scanning electron microscope. The thickness and crystallinity are shown in Table 1, and the composition of the outer layer and the layer thickness are shown in Table 3.
Among them, the product 6 of the present invention had an inner layer, an intermediate layer, and an outer layer made of a carbide of W ₃ Co ₃ C sequentially formed on the surface of the substrate. Then, using the products 1 to 6 of the present invention and the comparative products 1 to 4, a work material: S45C (HB190), and a cutting speed of 300 m
/ Min, feed: 0.5 mm / rev, depth of cut: 2.0
mm, cutting time: 60 min, first by dry cutting test
Cutting conditions and work material: S48C, cutting speed 150m / mi
n, feed: 0.3 mm / rev, depth of cut: 1.5 mm,
A cutting test was performed under a cutting time of 30 min under the second cutting conditions of the dry cutting test, and the average flank wear width was measured. The results are also shown in Table 3. Among these, the comparative product was in a state of abrasion damage accompanied by minute peeling. In addition, for the products 1 to 6 of the present invention and the comparative products 1 to 4, a peeling test of the coating layer was performed from the surface of the outer layer by a scratch test (a test method corresponding to a scratch hardness test method), and critical peeling at that time The load was determined and also shown in Table 3.

[0028]

[Table 1]

[0029]

[Table 2]

[0030]

[Table 3]

[0031]

As described above, the high-strength coating of the present invention can
Al) The wear resistance,
Since it has thermal shock resistance and chipping resistance, and especially excellent in peeling resistance of the coating, it has the effect of extending the service life in the area corresponding to the medium to high speed cutting area in this field. . Therefore, the high-strength coating of the present invention is:
Light cutting because of its excellent effect of achieving long life over a wide area from the low-speed cutting area to the high-speed cutting area, which is the area of conventional coating members, and the high toughness and high hardness of the film itself Excellent effects can be exhibited from the region to the heavy cutting region.

Continued on the front page (51) Int.Cl. ⁷ Identification code FI C23C 16/30 C23C 16/30 // B23B 27/14 B23B 27/14 A (72) Inventor Mamoru Kohata 580 Horikawa-cho, Saiwai-ku, Kawasaki-shi, Kanagawa Prefecture Address Solid Square Toshiba Tungaloy Co., Ltd. In-house (72) Inventor Yuichi Ikuhara 2-4-1 Rokuno, Atsuta-ku, Nagoya City, Aichi Japan (56) References JP-A-6-122959 (JP, A) JP-A-3-229882 (JP, A) JP-A-7-207459 (JP, A) JP-A-58-67865 (JP, A) JP-A-7-180071 (JP, A) (58) (Int.Cl. ⁷ , DB name) C23C 14/00-14/58 C23C 16/00-16/56 C22C 45/10 B23P 15/28 B23B 27/14

Claims (10)

(57) [Claims] 1. An intermediate layer containing at least 50% by volume of amorphous Ti or an amorphous substance containing Ti on a substrate made of a metal material, a sintered alloy or a sintered ceramic, and (Ti _a , Al _1-a ) C _x N _1-x [where Ti is titanium, Al is aluminum, and a is T
X represents the atomic ratio of i, and X represents the atomic ratio of carbon. Also, 0.4
5 ≦ a ≦ 0.54 and 0 ≦ X ≦ 0.5], and an outer layer made of a composite compound containing titanium and aluminum is coated. 2. The high-strength coated body according to claim 1 , wherein the total layer thickness of the intermediate layer and the outer layer is 0.5 to 10 μm. 3. An inner layer consisting of a single layer of a carbide containing Co and W or a solid solution containing Ti and W or two or more layers on a substrate made of a sintered alloy, and an amorphous layer formed on the surface of the inner layer. Ti or Ti-containing amorphous material and an intermediate layer containing more than 50 vol%, the surface of the intermediate layer (Ti _a,
Al _1-a ) C _x N _1-x [where Ti represents titanium, Al represents aluminum, a represents the atomic ratio of Ti, and X represents the atomic ratio of carbon. Also, 0.45 ≦ a ≦ 0.54 , 0 ≦ X ≦ 0.
5) is coated with an outer layer made of a composite compound containing titanium and aluminum. 4. The high-strength coating according to claim 3 , wherein the total layer thickness of the inner layer, the intermediate layer, and the outer layer is 0.5 to 10 μm. Wherein said inner layer, high-strength coating of claim 3 or 4, characterized in that a layer thickness of 0.005～1.5Myuemu. Wherein said intermediate layer is a high strength coated body according to any one of claims 1 to 5 oxygen atom ratio intermediate layer is characterized by comprising an oxide of 40% or less. 7. The intermediate layer is a high strength coated body according to any one of claims 1 to 6, characterized in that in Ti and / or Ti oxide comprising the following microcrystalline diameter 10 nm. 8. The intermediate layer has a thickness of 0.005 to 0.5 μm.
8. A film according to claim 1, wherein the film thickness is
2. The high-strength coating according to claim 1 . 9. The outer layer is any one of the preceding claims, characterized by comprising a layer thickness of 0.45~9.5μm
The high-strength coating according to the above item . 10. The substrate according to claim 1, wherein the substrate comprises Co and / or Ni.
Cubic comprising 4 to 15% by weight of a binder phase containing, as a main component, tungsten carbide, or tungsten carbide and carbides, carbonitrides, and mutual solid solutions of elements of groups 4a, 5a, and 6a of the periodic table. claims 1-9, characterized in that it consists of a cemented carbide comprising a hard phase of crystalline compound
The high-strength coating according to any one of the above.