JPS61104078A - Hard coated sintered alloy and its manufacture - Google Patents

Abstract

PURPOSE:To manufacture the titled hard coated sintered alloy having excellent adhesive strength by forming an inner layer consisting of a non-stoichiometric metallic compd. on the surface of a substrate consisting of a sintered alloy, and forming an outer layer consisting of diamond carbon, etc., on the surface of the inner layer. CONSTITUTION:A single or multilayered inner layer consisting of >=1 kind among solid solns. of a metal such as Ti, Zr, Hf, V, Nb, Ta, W, Mo, Cr, and Si or their alloy and a non-stoichiometric compd. consisting of the carbide, nitride, and oxide of 4a, 5a, and group 6a metals in the periodic table and the carbide and nitride of Si is coated on the surface of a substrate consisting of a sintered alloy contg. the carbide and nitride of 4a, 5a, and group 6a metals in the periodic table, their solid soln., etc., and contg. Fe, Ni, Co, W, Mo, Cr, etc. Then an outer layer consisting of diamond carbon and/or diamond is coated on the surface of the inner layer. When the outer layer is coated, carbon is diffused into the inner layer, and a non-stoichiometric compd. composed of 1 mole metallic element and 0.7 mole nonmetallic element is obtained. Consequently, a hard coated sintered alloy having high strength in the coated layer and excellent adhesive strength is obtained.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention provides a cutting tool in which a hard thin film of diamond-like carbon and/or diamond with excellent properties is formed on the surface of a substrate made of a sintered alloy. This invention relates to a hard-coated sintered alloy suitable for tools and wear tools, and a method for producing the same.

(Prior art) Ti (:, TiN) is applied to the surface of a sintered alloy made of a cemented carbide mainly composed of WC or a cermet mainly composed of TiC.

Sintered alloys coated with a wear-resistant material such as ^9.203 are widely used as tools, and even now these coating layers are made of wear-resistant materials and sintered alloys.・In relation to the base material. is being investigated.

On the other hand, cvn method, plasma CVD method, ion beam method,
Various methods have been proposed for creating a hard film made of diamond-like carbon or diamond using a laser beam method, an electron beam method, an ion implantation method, and the like. Attempts have been made to coat the surface of a substrate made of sintered alloy with a hard film made of diamond-like carbon or diamond and apply it to a tool, but it is currently impractical.

(Dark problem to be solved by the invention) There are two ways to create a hard film made of diamond-like carbon or diamond.
The ttS2 method is a solid-phase synthesis method that uses diamond-like carbon or diamond as the vapor source and heats and evaporates it to synthesize a hard film on the substrate surface. This is a vapor phase synthesis method that deposits a hard film on the surface of a substrate by thermal decomposition of hydrogen.

When a hard film made of diamond-like carbon or diamond is formed by these solid-phase synthesis methods or vapor-phase synthesis methods, carbon also precipitates simultaneously with the formation of the hard film, making it easy for soft carbon to be mixed in the hard film. For this reason, if a hard film made of diamond-like carbon or diamond is directly formed on the surface of a substrate made of a sintered alloy containing iron group metals, the carbon mixed in the hard film will react with the ferrous metals on the surface of the substrate and become trapped inside the substrate. Problems such as solid solution diffusion and generation of free carbon inside the substrate, resulting in a decrease in the strength of the substrate, poor adhesion between the substrate and the hard film, and furthermore, a decrease in the quality of the produced hard film. There is. In particular, when a hard film made of diamond-like carbon or diamond is formed on the surface of a substrate made of sintered alloy by vapor phase synthesis, the ferrous metal on the surface of the substrate becomes the hydrocarbon gas supplied for vapor phase synthesis. Therefore, there is a problem in that the amount of soft carbon such as amorphous carbon or graphite deposited on the surface of the substrate increases, and the solid solution diffusion of carbon into the interior of the substrate also increases. In order to improve these problems, the surface of the substrate made of cemented carbide is coated with carbides, nitrides, monoholides, oxides, etc. of group 4a, 5a, and 6a metals as an inner layer, and then the surface of this inner layer is A coated cemented carbide tool coated with diamond as an outer layer has been proposed. However, although such an inner layer has the effect of preventing carbon generated during the diamond coating process from diffusing into the substrate, it may generate free carbon within the inner layer and the outer layer, or cause the bonding between the inner layer and the diamond layer. Since carbon is also deposited on the interface, there is a problem in that the bonding strength within each layer or the adhesion strength at the interface between the inner layer and the outer layer decreases.
6 The present invention solves the above-mentioned problems. Specifically, the present invention solves the above-mentioned problems.
Or, a hard-coated sintered alloy with excellent strength in the WI layer and adhesion strength at the boundary surface of the Wi layer by preventing free carbon from being generated in the main layer and at the interface between the layers in the process of forming a hard film made of diamond. The object of the present invention is to provide a method for manufacturing the same.

(Means for Solving the Problems) The present inventors attempted to coat the surface of a substrate made of sintered alloy with a hard film made of diamond, and found that it was possible to apply it to tools. For master craftsmen who use tools under harsh conditions, we have confirmed that the adhesion strength between the base and the WI layer must be extremely high to withstand use. ! The present invention was completed by investigating the adhesion between the two layers.

That is, 1 the hard coated sintered alloy of the present invention is
, 5a, at least one of carbides, nitrides, and mutual solid solutions of group metals thereof, and Fe, Ni, Co.
, W, Mo 2 , and Cr(1), an inner layer made of a metal compound is formed on the surface of the substrate, and an outer layer made of diamond-like carbon and/or diamond is formed on the surface of the inner layer. In the coated sintered alloy, the inner layer comprises carbides, carbonitrides, carbonates, carbonitrides, carbonitides, carbides of Si, TR nitrides of metals of groups 4a, 5a, and 6a of the periodic table, and It is a hard-coated sintered alloy consisting of a single layer or multiple layers of at least one type of mutual solid solution and non-stoichiometric compound. The base body made of a sintered alloy in the hard-coated sintered alloy of the present invention must be selected to have a composition that has a rigidity or hardness that does not cause plastic deformation under externally applied loads, and is generally used. Cemented carbide or cermet, and depending on the application, Fe, Ni.

A sintered alloy similar to ceramics containing a trace amount of at least one of Co, W, Mo, and Cr may be used.In addition, the inner layer in the hard coated sintered alloy of the present invention may be a sintered alloy containing a trace amount of at least one of Co, W, Mo, and Cr. Group metal carbides 1 A compound consisting of at least one of carbonitrides, carbonates, carbonitrides, carbonitrides, Si carbides, carbonitrides, and mutual solid solutions thereof.

Furthermore, this compound is a non-chemical R-theoretical compound containing less non-metal elements than metal elements. In particular, the inner layer made of a non-stoichiometric compound is preferably made of a non-stoichiometric compound in an amount of 0.7 mol or more of a non-metallic element per 1 mol of a metal element, and the thickness of the inner layer is equal to that of the outer layer. In order to prevent carbon from the outer layer from diffusing into the substrate during the coating process and to maintain the strength of the entire RR layer,
Furthermore, the outer layer in the hard wave, overcast alloy of the present invention is made of diamond-like carbon and/or diamond, and its thickness is preferably 0.54 m to 5 pin. It is desirable that the total thickness of the coating layer, which is the sum of these inner and outer layers, is 1 to 10
A thickness of 4 m is desirable, and a thickness of 1 to 4 IL m is particularly desirable when applied to tools with sharp cutting edges such as drilling tools. Also contains crystalline materials, electrical resistance, and light transmittance.

Indicates something that has properties such as hardness that are similar to diamond.

When the hard-coated sintered alloy of the present invention forms an inner layer made of a non-stoichiometric compound directly on the surface of a substrate, carbon contained in the substrate diffuses into the inner layer in the process of forming the inner layer. For example, η phase (WsCozG
) may result in brittle phases due to lack of carbon. Therefore, if the substrate surface layer contains 'M free carbon, or the substrate surface layer contains almost no iron group metals such as Co or Ni, the substrate surface layer should contain carbides and nitrides of metals from groups 4a, 5a, and 6a of the periodic table. It is also possible to use a substrate having a B-1 type solid solution having a face-centered cubic crystal structure consisting of at least two or more of the following. In particular, the type and thickness of the inner layer made of a non-stoichiometric compound can be easily adjusted without deteriorating the alloy properties of the substrate, and free carbon generated when forming an outer layer on the surface of the inner layer can be removed from the inside of the substrate. It is desirable to have an inner layer that prevents diffusion into the substrate.
A first inner layer consisting of a single layer or multiple layers of at least ill of group A metal carbides, nitrides, oxides, oxidized compounds, and mutual solid solutions thereof is formed, and the periodic table is formed on the surface of the first inner layer. 4a, 5a, 6a group metal carbides, carbon, nitrides,
carbonate, carbonitride oxide 1 degree tetrahide or Si carbide,
Forming an i2 inner layer consisting of a single layer or multiple layers of a non-stoichiometric compound which is at least 18i of carbonitride or a mutual solid solution thereof, and diamond-like carbon and/or diamond-like carbon is formed on the surface of this second inner layer. Or a coated sintered alloy with an outer layer made of diamond.

The method for producing a hard-coated sintered alloy of the present invention includes a substrate made of a commercially available cemented carbide mainly composed of WC or a cermet mainly composed of Tic, or a carbide, nitride, or At least one of these mutually solid solution contains Fe and Fe.

At least one of Ni, Co, W, Mo, and Cr
Using a substrate made of a sintered alloy prepared by a conventional powder metallurgy method, the surface of this substrate is subjected to pretreatment such as polishing and cleaning, and then subjected to T i and Z r .

Hf, V, Nb, Ta, W,
At least one metal or alloy of MO, Cr, and Si is applied by conventional wet plating method or physical vapor deposition (PVD).
Or uncoated by chemical vapor deposition (G, V'D) or periodic table 4a.

Carbides and nitrides of group 5a and 6a metals, ! 11
a non-stoichiometric compound consisting of a 11 compound or a carbide of St,
An inner layer consisting of a single layer or multiple layers coated with a non-stoichiometric compound consisting of nitride or at least one of these mutual solid solutions by conventional physical vapor deposition or chemical vapor deposition is formed on the surface of the substrate. Then, an outer layer made of diamond-like carbon and/or diamond is formed on the surface of this inner layer.

Free carbon generated when forming this outer layer is diffused and dissolved into an inner layer consisting of a single layer or multiple layers of at least one metal, alloy, or non-stoichiometric compound,
This inner layer is made of a non-stoichiometric compound containing 067 moles or more of a non-metallic element per 1 mole of a metal element. As a method for forming the outer layer on the surface of the inner layer, an internal phase synthesis method in which diamond powder is heated with a laser or electron beam in a vacuum, or a solid phase synthesis method using other PVD methods (ion blasting, sputtering, etc.) may be used. I can do it. Also,
It is also possible to use a gas phase synthesis method in which a gas consisting of a hydrocarbon such as methane and hydrogen is thermally decomposed at 300° C. to 1300° C. during high frequency or microwave discharge.

Furthermore, a vapor phase synthesis method applying a known CVD method, plasma CVD method, or ion implantation method can also be used. In particular, when the inner layer formed on the surface of the substrate is made of metal or alloy by wet plating or PVD, it is desirable because carbon and nitrogen on the surface of the substrate are difficult to diffuse into the inner layer during the inner layer coating process.

In the method for producing a hard-coated sintered alloy of the present invention, the inner layer formed on the surface of the substrate is formed by the PVD method.

Periodic table 4a by CVD method or plasma CVD method,
Coated as a first inner layer consisting of a single layer or a multilayer of at least one of carbides, nitrides, oxides, nitrides, and mutual solid solutions of metals of groups 5a and 6a, and the surface of the first inner layer Ti is formed by wet plating or PVD on
,Zr,If.

V, Nb, Ta, W, Mo,
Cr, S f (7) Metal or alloy and PV
Periodic table 4a, 5a formed by D method, CVD method or plasma CVD method.

A non-stoichiometric compound consisting of a carbide, nitride, or first-layer oxide of a group 6a metal, or a carbide of Si.

It is coated as a second inner layer consisting of a single layer or multiple layers made of a non-stoichiometric compound of nitride or at least one of these mutual solid solutions, and the surface of this second inner layer is coated with a solid phase synthesis method or a gaseous method. The outer layer is coated by a phase synthesis method. In this way, the inner layer consisting of the first inner layer and the second inner layer easily prevents carbon and nitrogen on the surface of the substrate from diffusing into the inner layer when forming the inner layer, and also prevents free carbon and nitrogen generated when forming the outer layer. This is desirable because carbon diffuses into solid solution within the inner layer and prevents it from diffusing into the interior of the substrate.

(Function) The hard-coated sintered alloy of the present invention is a coated sintered alloy with excellent wear resistance because the outer layer of diamond-like carbon and/or diamond is formed as a high-quality hard thin film with excellent hardness. It is. In addition, the outer layer made of a hard thin film has strong adhesion at the boundary between the outer layer and the inner layer by diffusing and dissolving free carbon generated in the process of forming the outer layer in the inner layer. It is a coated sintered alloy with excellent peeling resistance. moreover.

The inner layer has excellent wettability and reactivity with the iron group contained in the substrate, making the adhesiveness at the boundary between the inner layer and the substrate strong, and the resistance of the inner layer! 1. It is a coated sintered alloy with excellent female characteristics. In particular, when the inner layer consists of a first inner layer and a second inner layer, when the inner layer is formed, there is less fluctuation of chlorine and nitrogen on the surface of the substrate, and the adhesion between the inner layer and the substrate is improved. It is a coated sintered alloy with excellent properties.

(Example) Example 1 As a substrate - (wcso%, Ti(:5%, Co5%).

(wt%) A sintered alloy with the composition is made in the shape of CIS standard 5NG432, the surface of this 5NG432 is thoroughly washed with detergent, organic solvent, acid, alkali, water, etc., and after drying, it is set in an ion blating device. did. After evacuating the inside of this device to 0.001 Pa, the degree of vacuum inside the furnace was reduced to 0.00 Pa.
The substrate was gradually heated to 800° C. while maintaining the temperature at 0.013 Pa. Next, the surface of the substrate was bombarded with high-purity argon gas for 40 minutes, and then the metal tantalum was evaporated to coat the surface of the substrate with Ta. T at this time
The deposition rate of the coating layer a is 6 x 10-' p, m
/sec, and the thickness of the Ta coating layer was about 2 μm. Plasma CV
D equipment was equipped with 2450 MH2(7)-F microwave, output of aoo w, system pressure of 87OOPa,
200 Crow'/ sin H2, 3"/ sin ClA
The substrate was reacted for 5 hours while being heated to 900° C. under the conditions of No. 4 to coat a diamond hard layer with a thickness of about 21 Lm.

The hard coated sintered alloy of the present invention produced in this way (1
), as a result of microscopic observation and X-ray analysis, the inner layer is TaCo,
7, and it was confirmed that the outer layer was a layer containing a large amount of diamond.

As a comparative example, when the white metal tantalum was evaporated under the conditions of Example 1, the atmosphere was made to have an acetylene gas partial pressure of 0.1 OPa, and the other conditions were the same as in Example 1, so that the inner layer contained TaC and the outer layer contained a large amount of diamond. A comparative layer was prepared consisting of a layer containing

Using the hard coated sintered alloy (1) of the present invention and the comparative amount (1), an Al alloy was cut at a cutting speed of 890 m/si.
n, feed 0.15m5/re? As a result of a turning test conducted under the condition of a cutting depth of 0.35 mm, the hard coated sintered alloy (1) of the present invention showed normal wear even after 230 minutes of cutting, whereas the comparative material (1) showed normal wear even after 100 minutes of cutting. After cutting, the coating layer peeled off.

Example 2 The substrate was -(wc7j%, Ti010%, -TaQ
to%.

Sintered alloy with Co8% (wt%) composition is CIS standard 5NG
After cleaning and drying the surface of this 5NG432 in the same manner as in Example 1, it was placed in an ion blating apparatus.Then, as in Example 1, the inside of the furnace was evacuated and the substrate was heated at 5H°C. bombarded with high purity argon gas while maintaining After that, while evaporating the metallic titanium, the inside of the furnace was set to a nitrogen gas partial pressure of 0.05 Pa and held for 5 minutes, then the nitrogen gas was exhausted and the metallic titanium was evaporated in a vacuum for 5 minutes.
In addition, the metal titanium 5
The inner layer was coated on the surface of the substrate by repeating evaporation of titanium metal in an atmosphere of nitrogen gas partial pressure of 0.05 Pa and a vacuum atmosphere for minutes. This inner layer was found to be T1No.6 as a result of X-ray diffraction, and the substrate to which this inner layer was attached was used in Example 1.
In the same manner as above, the surface of the inner layer was coated with an outer layer containing a large amount of diamond and having a thickness of about 2 pm. The hard-coated sintered alloy (2) of the present invention produced in this way is manufactured by fJ MicroKanryo and X
As a result of line diffraction, the inner layer was 21 Lm thick Ti (No. 6.
C1o4)o9s, and it was confirmed that the outer layer was a layer containing a large amount of diamond.

As a comparative amount, when white metal titanium was evaporated under the conditions of Example 2, an atmosphere of nitrogen gas partial pressure of 0.13 Pa was continued, and the other conditions were the same as in Example 2, so that the inner layer was made of TiM.
A comparative amount (2) was prepared in which the outer layer consisted of a layer containing a large amount of diamond.

As a result of conducting a turning test on A1 alloy under the same conditions as in Example 1 using the hard coated sintered alloy (2) of the present invention and the comparative amount (2), it was found that the hard coated sintered alloy (2) of the present invention had normal wear even after 250 minutes of cutting, whereas comparative amount "(2)" had normal wear after 250 minutes of cutting.
After cutting for 0 minutes, peeling of the lI layer occurred.

Example 3 As a substrate (WC74%, T1Co, 7NO, 31
A sintered alloy with a composition of 0% TaCl, 0% TaCl, and 6% Co (wt%) was created in the shape of CIS standard 5FCN53Z.
5FCN53Z 17) The surface was washed and dried in the same manner as in Example 1, and then set in an ion blating device.

The inside of this apparatus was evacuated, and the substrate was gradually heated to 500
℃, after bombarding the substrate surface with argon gas for 20 minutes, 10% as the reaction gas was evaporated while metallic titanium was being evaporated.
TiGo, zNo, r were formed as a first inner layer in an atmosphere of cH4-80%M2 gas partial pressure 0.10 Pa, and then, after exhausting the reaction gas once, a second inner layer of T1No6 was formed under the same conditions as in Example 2. and coated with an outer layer containing a large amount of diamond. As a result of microscopic observation and X-ray diffraction, the hard-coated sintered alloy (3) of the present invention thus produced was found to have a first inner layer of T1Co and 3N with a thickness of about 1JLm.
The second inner layer is made of Tr (No.6.Go) with a thickness of about 1 pm.
, a>o, qs, and it was confirmed that the outer layer was a layer containing a large amount of diamond of about 2 pm.

As a comparative quantity, a comparative quantity (3) was prepared in which an inner layer was prepared under the same conditions as the first inner layer in Example 3, and then an outer layer made of diamond was formed on the surface thereof in the same manner as in Example 1.

Using the hard-coated sintered alloy (3) of the present invention and the comparative amount (3), Ai-15%St alloy was used as the work material, cutting speed was 500 1 in, feed rate was 0.2 mm/tooth. As a result of conducting a milling cutting test under the following conditions: 1. The hard coated sintered alloy of the present invention (
In the case of 3), none of the four pieces had peeled off, whereas in the comparative sample, three out of four pieces had peeled off and had reached the end of their service life.

Example 4 Micron drill made of cemented carbide equivalent to CIS standard KIO (helix angle 30°, tip angle 120', cutting edge diameter 0)
．． 50φms) was used as a substrate, and this substrate was set in an ion plating apparatus. The interior of this attachment was treated in the same manner as in Example 1 to achieve a substrate temperature of eoo''c and a nitrogen gas partial pressure of 0.1.
After evaporating metal tantalum at 0 Pa to form a first inner layer, exhausting nitrogen gas and evaporating metal tantalum in a vacuum of 0.013 Pa to form an fjS2 inner layer, then forming an outer layer in the same manner as in Example 1. coated. This hard coated sintered alloy of the present invention (0 is the result of microscopic observation and X-ray diffraction;
A first inner layer of TaN of Lm thickness and TaCo of lILm thickness.
, 8 and a 1.54 m thick outer layer containing a large amount of diamond.

As a comparative quantity, a comparative quantity (0) was prepared consisting of an lpm thick diamond-rich outer layer and a diamond-rich outer layer obtained by omitting the step of forming the second inner layer using the same substrate.

Using the hard coated sintered alloy (4) of the present invention and the comparative amount (4), cutting was performed using a workpiece made of three stacked multilayer IC boards (thickness: 16mm) consisting of copper plates and epoxy plates. Speed 250s
/gin and feed rate of 0.05m5/rev, the results showed that the hard coated sintered alloy of the present invention (
4) was able to drill 75,000 holes, whereas comparative amount (4) suffered from peeling after 7,000 holes and reached the end of its life.

Example 5 A substrate having the same composition as in Example 1 was used, and after being subjected to the same treatment as in Example 1, it was placed in a high frequency sputtering apparatus. After evacuating the inside of this apparatus to 0.001 Pa, metal titanium was sputtered in an atmosphere with a nitrogen gas partial pressure of 0.13 Pa, and then the nitrogen gas was exhausted and the pressure was 0.001 Pa.
After creating a vacuum atmosphere of 8.8 Pa, an Ar gas atmosphere of 8.8 Pa was created, and metallic tungsten was sputtered at an output of 300 W for 30 minutes. Plasma c
It was set in a vn apparatus and coated with a diamond hard layer under the same conditions as in Example 1.

This hard coated sintered alloy (5) of the present invention can be observed by microscopic observation,
Analysis by X-ray diffraction and scanning Auger electron spectroscopy shows that the first inner layer is approximately 3 pm thick TiN and the second inner layer is approximately 5 pm thick.
pm thick tungsten carbide.

The outer layer was approximately 21 Lm thick diamond. child
Of the tungsten carbide in the second inner layer, the outer layer on the side in contact with diamond was close to WC, and the first inner layer on the side in contact with TiN was close to W2C. That is, the second inner layer had a concentration gradient consisting of a stoichiometric compound, which is WC, and a non-stoichiometric compound, W Cxcx :20.5).

As a comparison sample, a comparison sample (5) was prepared under the conditions of Example 5, omitting the second inner layer step, and coating the surface of the inner layer made of TiN with an outer layer made of diamond.

The hard coated sintered alloy (5) of the present invention and the comparative amount (5) were subjected to a peeling resistance test of the coating layer using a scratch tester equivalent to a scratch hardness tester. As a result, the hard coated sintered alloy of the present invention For gold (5), the coating layer did not peel off up to a load of 6 kg, whereas for comparison weight (5), the coating layer slightly peeled off at a load of 3 kg, and at 18J load of gold (4), the coating layer peeled off significantly. did.

(Effects of the Invention) As a result of the above, the hard coated sintered alloy of the present invention has excellent wear resistance and peeling resistance, and can be used in applications where a certain degree of impact is applied, such as turning tools as well as price tools. ,
It is an industrially useful tool that can be applied to cutting tools, including drilling tools such as end mills, drills, and micron drills for semiconductor substrates, as well as wear-resistant tools, including the tips of printing pins and slitters for cutting paper, tape, etc. It is the material.

Claims (8)

[Claims] (1) At least one of carbides, nitrides, and mutual solid solutions of metals from groups 4a, 5a, and 6a of the periodic table and Fe
, forming an inner layer made of a metal compound on the surface of a substrate made of a sintered alloy containing at least one of Ni, Co, W, Mo, and Cr, and an outer layer made of diamond-like carbon and/or diamond on the surface of the inner layer. In the coated sintered alloy, the inner layer is a carbide, carbonitride, carbonide, carbonitride, carbonitride, carbonitride, or carbide or carbonitride of Si, or A hard-coated sintered alloy characterized by being a single layer or multilayer consisting of at least one of these mutual solid solutions and a non-stoichiometric compound. (2) The inner layer has a nonmetallic element (
Carbon, nitrogen, oxygen, and boron are shown below. ) 0.7 mol or more of a non-stoichiometric compound, and the inner layer has a thickness of 0.1
The hard coated sintered alloy according to claim 1, wherein the hard coated sintered alloy has a diameter of μm to 10 μm. (3) The hard coated sintered alloy according to claims 1 and 2, wherein the outer layer has a thickness of 0.5 μm to 5 μm. (4) Fe and at least one of carbides, nitrides, and mutual solid solutions of metals from groups 4a, 5a, and 6a of the periodic table;
, forming an inner layer made of a metal compound on the surface of a substrate made of a sintered alloy containing at least one of Ni, Co, W, Mo, and Cr, and an outer layer made of diamond-like carbon and/or diamond on the surface of the inner layer. In the coated sintered alloy, the inner layer is composed of a first inner layer on the side adjacent to the base body and a second inner layer on the side adjacent to the outer layer, and the first inner layer is made of a metal of group 4a, 5a or 6a of the periodic table. At least one of carbides, nitrides, oxides, borides, and mutual solid solutions thereof
The second inner layer is a carbide, carbonitride, carbonide, carbonitride, carbonitride, carbonitride, or carbide or carbonitride of a metal of group 4a, 5a, or 6a of the periodic table. 1. A hard-coated sintered alloy, characterized in that it is a single layer or a multi-layer consisting of a non-stoichiometric compound, or a mutual solid solution of these compounds. (5) The second inner layer is made of a non-stoichiometric compound containing 0.7 mole or more of a nonmetallic element per mole of a metal element, and the thickness of the second inner layer is 0.1 μm to 10 μm. A hard-coated sintered alloy according to claim 4 characterized by: (6) The hard coated sintered alloy according to claims 4 and 5, wherein the outer layer has a thickness of 0.5 μm to 5 μm. (7) Fe and at least one of carbides, nitrides, and mutual solid solutions of metals from groups 4a, 5a, and 6a of the periodic table;
, Ti, Zr, Hf,
Non-stoichiometric compounds consisting of metals or alloys of V, Nb, Ta, W, Mo, Cr, Si and carbides, nitrides, oxides, borides of metals of groups 4a, 5a, 6a of the periodic table, or Si
A step of coating an inner layer consisting of a single layer or multiple layers of at least one of non-stoichiometric compounds of carbides and nitrides or mutual solid solutions thereof, and coating the surface of the inner layer with diamond-like carbon and/or diamond. A method for manufacturing a coated sintered alloy by coating an outer layer consisting of 0.7 of a nonmetallic element per mole of a metal element by diffusing carbon into the inner layer in the step of coating the outer layer. A method for producing a hard-coated sintered alloy, characterized by forming a non-stoichiometric compound in a molar or more amount. (8) Fe and at least one of carbides, nitrides, and mutual solid solutions of metals from groups 4a, 5a, and 6a of the periodic table;
, Ni, Co, W, Mo, and Cr.
, a step of coating a first inner layer consisting of a single layer or a multilayer of at least one of group 6a metal carbides, nitrides, oxides, borides, and mutual solid solutions thereof, and coating the surface of the first inner layer with Ti. , Zr, Hf, V, Nb, Ta, W, Mo, Cr
, Si metals or alloys and periodic table 4a, 5a, 6a
A monolayer of at least one of non-stoichiometric compounds of group metal carbides, nitrides, oxides, and borides, or non-stoichiometric compounds of Si carbides and nitrides, or mutual solid solutions thereof. or a step of coating a second inner layer consisting of multiple layers, and coating the surface of the second inner layer with diamond-like carbon and/or
Alternatively, a method for producing a coated sintered alloy by coating an outer layer made of diamond, wherein carbon is diffused into the second inner layer during the step of coating the outer layer, so that the second inner layer is coated with a carbon dioxide per mole of the metal element. 1. A method for producing a hard coated sintered alloy, the method comprising: forming a non-stoichiometric compound containing 0.7 mol or more of a nonmetallic element.