JP2000355777A - Surface coated sintered alloy excellent in adhesion and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a surface coated sintered alloy improved in the adhesion of a hard film and improved in the life of a tool by paying attention to the boundary between a sintered alloy base material and a hard film and increasing bonding strength between the base material and the hard film and to provide a production method thereof. SOLUTION: This is a surface coated sintered alloy in which a sintered alloy composed of cemented carbide or cermet contg. a hard phase and a bonding phase is used as a base material, and the surface of the base material is coated with a hard film composed of at least one kind of single layer or laminate of >= two layers selected from the carbides, nitrides and oxides of the group 4a, 5a and 6a elements in the Periodic Table, aluminum and silicon and mutual solid solutions thereamong. In the hard film coated just on at least the hard phase particles in the boundaries between the base material and the hard film, a diffusion element-contg. layer in which at least one kind of diffusion element different from the elements composing the hard film is almost uniformly diffused is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a surface-coated sintered alloy in which a hard film is coated on a surface of a sintered alloy base material made of a cemented carbide or a cermet containing a hard phase and a binder phase, and a method for producing the same. Specifically, by focusing on the interface between the sintered alloy base material and the hard film, the surface strength is improved by increasing the bonding force between the base material and the hard film, thereby improving the adhesion of the hard film and improving the tool life. The present invention relates to a coated sintered alloy and a method for producing the same.

[0002]

2. Description of the Related Art A surface-coated sintered alloy obtained by coating a hard alloy such as a cemented carbide or a cermet with a hard film such as TiC, TiCN, TiN or Al ₂ O ₃ by a chemical vapor deposition method or a physical vapor deposition method. Since the steel has both the strength and toughness of the base material and the wear resistance of the hard film, it is widely used as a cutting tool, a wear-resistant tool, and a part. However, if the adhesion between the base material and the hard film is poor, abrasion proceeds rapidly due to peeling of the hard film during use, and the life is shortened. In general, the adhesion between the base material and the hard film is greatly affected by the diffusion state of the constituent components constituting the sintered alloy into the hard film. For this purpose, methods for improving the adhesion between the base material and the hard film include adjusting the surface of the base material, selecting the material of the hard film adjacent to the base material,
Attempts have been made to interpose an underlayer at the interface between the base material and the hard film, and to optimize the coating conditions of the hard film or the underlayer adjacent to the base material.

A number of proposals have been made on the adhesion between a base material and a hard film, which is one of the problems in a surface-coated sintered alloy in which a hard film is coated on the surface of a sintered alloy. One of the methods proposed to improve the adhesion between the base material and the hard film is a method of diffusing the composition of the sintered alloy base material into the hard film. JP-A-07-243023, JP-A-08-118105
JP, JP-A-08-187605, JP-A-09-09609
-262705 and JP-A-05-263252
There is an official gazette.

[0004] On the other hand, the surface of a sintered alloy generally has a mechanically worked surface that is mechanically worked by grinding or the like after sintering, depending on the application, and a product that has not been mechanically worked and is almost sintered. A product having a sintered surface in a later state and a product having both of these surface states. Among the surface states of these sintered alloys, the mechanically processed surface has processing dust containing Co adhered to the surface relatively uniformly, but has a problem that a deteriorated layer remains near the surface. In addition, although there is no work-affected layer on the sintered skin surface, there is a problem that the surface of the hard phase particle is so uneven that the binder phase does not exist on the hard phase particles, and the adhesion between the hard phase and the hard film is poor. Examples of the work-affected layer described herein include cracks in the hard phase particles, interface defects between the hard phase particles or between the hard phase particles and the binder phase, and transformation of the binder phase. As described above, many proposals have been made to improve the surface of a sintered alloy having a mechanically worked surface or a sintered surface, and typical examples thereof are described in JP-A-06-108253 and JP-A-05-1.
23903 and JP-A-07-097603.

[0005]

Among the prior arts related to the present invention, it is disclosed in Japanese Patent Application Laid-Open No. H07-07207 that the composition constituting the base material of the sintered alloy is diffused into the hard film.
-243020, JP-A-08-118105, JP-A-08-187605 and JP-A-09-09605
No. 262705 discloses a chemical vapor deposition method (hereinafter referred to as C
VD method), the surface of the WC-base
a first layer of iC or TiN, a second layer of TiCN containing columnar crystals (described as a vertically elongated crystal structure), a third layer of TiC, TiCO, etc., and Al ₂ O containing copper type crystals. _The hard film consisting of the fourth layer of ₃ is sequentially coated,
A cutting tool made of a surface-coated tungsten carbide-based cemented carbide in which at least W and Co among components constituting the cemented carbide base material are diffused and contained in the first layer and the second layer or the first to third layers is disclosed. ing.

[0006] The cutting tools made of surface-coated tungsten carbide-based cemented carbide disclosed in these publications have improved adhesion due to diffusion of W and Co into the hard film. However, when the diffusion layer in the hard film is minutely observed just above the surface of the base material, the diffusion layer is extremely unevenly formed, and the diffusion layer is extremely thick and has a large amount of diffusion on Co as the binder phase. , A hard phase of tungsten carbide or (W, T
There is almost no diffusion layer on a cubic structure compound such as i, Ta) C. Due to such an interface state between the hard film and the base material, there is a problem that the adhesion between the hard film and the base material is not sufficiently improved.

Japanese Patent Application Laid-Open No. 05-263252 discloses that a first layer made of TiC on the surface of a cemented carbide base material, a second layer made of TiCN having a lattice constant of 4.251 to 4.032%, There is disclosed a coated cemented carbide member coated with a hard film composed of a third layer composed of: The coated cemented carbide members disclosed in these publications are capable of preventing the diffusion of tungsten and the like from the cemented carbide base material and the absorption of carbon during the formation of a hard film, thereby providing wear resistance and chipping resistance as a cutting tool. Gender improvement. That is, in the coated cemented carbide member disclosed in the publication, the first layer TiC and the WC in the cemented carbide base material have relatively excellent adhesion, and the carbon content and nitrogen in the second layer TiCN are relatively high. It is intended to prevent carbon diffusion from the base material by increasing the amount. However, the coated cemented carbide member disclosed in this publication tends to generate an η phase as a fragile Co-WC composite carbide at the interface between the base material and the hard film, and conversely enhances the adhesion of the hard film. Since it is difficult to form a diffusion layer due to diffusion of Co and W, which has a high effect, there is a problem that there is a limit in improving the adhesion between the base material and the hard film.

On the other hand, of the prior art relating to the base material surface,
Japanese Patent Application Laid-Open No. H06-108253 discloses that the surface of a cemented carbide is, for example, brush-polished to have an average surface roughness Ra of 0.15 to 0.15.
There is disclosed a coated cemented carbide in which a hard film is coated on a surface having a polishing scratch formed at 0.4 μm and in a random direction. The coated cemented carbide disclosed in the publication, compared with the adhesion effect of grinding chips generated by brush polishing, the effect of Co deposited slightly uniformly on the hard particles on the surface of the cemented carbide, hard coating film Although the adhesion to the base material is enhanced, there is a problem that the adhesion amount of Co is small and the effect of improving the adhesion is insufficient due to the accompanying process-altered layer.

Japanese Unexamined Patent Publication No. 05-123903 discloses that a cemented carbide alloy whose surface is ground and then re-sintered in a high-pressure inert gas atmosphere at a liquid phase appearance temperature or higher is used as a base material, Discloses a method of manufacturing a surface-coated WC-based hard metal cutting tool member having a hard film formed on a base material surface. Further, Japanese Patent Application Laid-Open No. 07-097603 discloses that the edge of a cemented carbide tip is subjected to an arc honing process of R = 0.03 mm and then re-sintered in an atmosphere of 1% N ₂ -99% Ar. A ceramic base material for diamond coating having a nitrogen-containing uneven layer formed on the surface and a method for producing the same are disclosed. The surface of the re-sintered skin surface disclosed in both of these publications has a slightly improved adhesion due to the complete removal of the affected layer, but the Co adhered to the hard particles by grinding. Is lost by resintering, so that a diffusion layer is not formed, and the effect of improving adhesion is insufficient. In addition, the surface of the re-sintered surface disclosed in both publications has a problem that the work material is apt to adhere to the surface due to the increase in unevenness, which causes film peeling and a decrease in finished surface accuracy.

[0010]

DISCLOSURE OF THE INVENTION The present inventors have been studying a method for greatly improving the adhesion between a base material and a film in a surface-coated sintered alloy for many years. First finding that, at the interface between the material and the hard film, the adhesion is improved by forming a diffusion element-containing layer in which at least the iron group metal and the tungsten element constituting the base material are diffused in the hard film. I got Diffusion at this time becomes remarkable on the binder phase containing iron group metal as a main component, hardly occurs on the hard phase particles containing tungsten, and because an uneven diffusion layer is formed on the surface of the base material. The second finding was that sufficient adhesion could not be improved. In order to obtain a uniform diffusion element-containing layer, the iron group metal may be dispersed or coated on the hard phase particles in advance, and the hard film may be formed after dispersing or coating the iron group metal on the base material surface. The third finding was that the coated sintered alloy was excellent in adhesion. Based on these first to third findings, the present invention has been completed.

The surface-coated sintered alloy having excellent adhesion according to the present invention has a base material of a cemented carbide or a cermet-based sintered alloy containing a hard phase and a binder phase, and has a periodic table on the surface of the base material. A hard film comprising a single layer or a laminate of two or more layers selected from the group 4a, 5a and 6a elements, aluminum, silicon carbide, nitride, oxide and their mutual solid solutions A surface-coated sintered alloy, wherein at least one type of diffusion different from an element constituting the hard film is included in the hard film coated at least on the hard phase particles at an interface between the base material and the hard film; This is one in which a diffusion element-containing layer in which elements are diffused almost uniformly is formed.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The base material of the surface-coated sintered alloy of the present invention specifically includes a hard phase composed of only tungsten carbide and a binder phase containing Co and / or Ni as a main component. For example, WC-Co alloy, WC-Ni alloy, WC- (Co, Ni) alloy, WC- (Ni, C
r) -based alloy, WC- (Co, Cr) -based alloy, WC- (C
o, Cr, V) based alloys, a hard phase composed of tungsten carbide and a cubic structure compound composed of compounds of Group 4a, 5a and 6a elements of the periodic table, and Co as a main component Consisting of a binder phase, for example WC-TaC-Co
Alloy, WC- (W, Ti, Ta) C-Co alloy, W
A representative example is a cemented carbide made of a C- (W, Ti, Ta, Nb) (C, N) -Co alloy.

[0013] Among the base materials, cermets include:
It is composed of a hard phase mainly composed of Ti (C, N), TiN and TiC and a binder phase mainly composed of Co and / or Ni. Specifically, Ti (C, N)- (T
i, W) C- (Co, Ni) alloy, Ti (C, N)-
(Ti, W) (C, N)-(Co, Ni) alloy, Ti
(C, N)-(Ti, W, Ta) C- (Co, Ni) -based alloy, Ti (C, N)-(Ti, W, Ta) (C, N)
A cermet made of a (Co, Ni) -based alloy can be cited as a typical example.

Among these base materials, the hard phase is tungsten carbide, or tungsten carbide and 4a, 5 in the periodic table.
a, 6a element comprising at least one cubic structure compound selected from carbides, nitrides, carbonates, nitrides and mutual solid solutions thereof, wherein the binder phase contains cobalt and / or nickel. The use of a cemented carbide as a main component is preferable because the base material has excellent strength, toughness, impact resistance, thermal shock resistance, plastic deformation resistance, and the like.

The hard film to be coated on the surface of the base material is specifically formed by, for example, a chemical vapor deposition method (hereinafter, referred to as “CVD method”), a physical vapor deposition method (hereinafter, referred to as “PVD method”), or a plasma CVD method. TiC, T having a thickness of 1 to 20 μm produced by one or a combination of two or more of
iCN, TiN, (Ti, Zr) N, (Ti, Al)
A single-layer film typified by N and CrN, a stack of a first layer of TiC, a second layer of TiN, a third layer of TiCN, a fourth layer of TiN, a first layer of TiN, 2nd layer-A
Stack consisting of third layer of l ₂ O ₃ , first layer of TiN-TiCN
Fourth So TiN third So Al ₂ O ₃ of the second So TiC of
Of TiN, the first layer of TiN-(Ti, Al)
A stack of the second layer of N and the third layer of TiN, the first layer of TiN
Layer—Laminated layer composed of second layer of Si ₃ N ₄ , First layer of CrN—V
A stacked film typified by a stacked structure including the second layer of N can be given.

In these hard films, the first layer coated adjacent to the base material is TiN, TiC, TiCN, (Ti, A
1) When the material is composed of one of nitride, nitrided carbide and carbide containing titanium represented by N, (Ti, Al) CN, the consistency between the base material and the first layer is excellent. That, first
This is preferable because a later-described diffusion element is easily diffused into the layer to further enhance the adhesion.

This diffusion element is not limited as long as it is a substance having excellent adhesion to the base material, particularly the hard phase contained in the base material, and the diffusion element is easily diffused into the hard film. Such a diffusion element is a diffusion element having excellent compatibility with a hard film. It is preferable that the diffusion element contains at least an element constituting the base material, since it has excellent adhesion to the hard phase contained in the base material. Specifically, the diffusion elements are 4a, 5a, 6 in the periodic table.
A typical example is a case in which one or more of a group a metal element, Co, Ni, and Fe are contained.

Among these diffusion elements, it is preferable that one or more of the iron group elements, tungsten and carbon are contained, and the ratio of these elements in the diffusion element containing layer formed by the diffusion elements is It is preferable that the content of at least 3 to 15 at% in terms of the average content of both tungsten and tungsten is more excellent in adhesion to the hard phase in the base material.

When a diffusion element-containing layer formed by diffusing at least one of these diffusion elements almost uniformly into the hard film is formed at the interface between the base material and the hard film, the entire hard film is diffused. It may be formed as an element-containing layer. The maximum thickness of the diffusion element-containing layer is the thickness of the hard film. This diffusion element-containing layer improves the adhesion of the hard film when the diffusion element is formed by diffusing the diffusion element into the hard film immediately above the bonding phase and the hard phase of the base material at the interface between the hard film and the base material. However, this is preferable because the effect of improving the life is remarkable.

Specifically, the diffusion element-containing layer is used for analyzing a minute portion of a hard film in a cross section of a surface-coated sintered alloy.
It is preferable that an iron group element and tungsten are contained immediately above a hard phase particle of a base material such as WC, (W, Ti, Ta) C, and in particular, a composite comprising one or more iron group elements, tungsten and carbon It is preferable to use a carbide or a structure in which this composite carbide is mixed in a hard film because the effect of enhancing the adhesion of the hard film immediately above the hard phase of the base material is remarkable.

Further, when an iron group metal layer having an average thickness of 0.5 μm or less is present at the interface between the base material and the diffusion element-containing layer, particularly at the interface between the hard phase particles contained in the base material and the diffusion element-containing layer. It is preferable because the adhesion between the hard phase particles and the hard film may be further improved. Further, the surface of the base material at the interface between the base material and the diffusion element-containing layer is made of hard phase particles having a size of 0.2 μm or more, and when no crack is present in the hard phase particles, it is accompanied by mechanical processing. This is preferable because the work-affected layer is removed from the surface of the base material, and the adhesion of the hard film is further improved.

The surface-coated sintered alloy of the present invention having excellent adhesion can be formed by various conventional surface-coating sintering processes using a conventional sintered alloy produced by powder metallurgy or a commercially available sintered alloy as a base material. Applying a method of manufacturing bonded gold and various coating materials, specifically, a gas phase method, a liquid phase method, a solid phase method or a method combining these, and the like, a diffusion element containing layer and a hard layer are formed on the surface of the base material. It can be produced by forming a film, but if performed by the following method, it is a simple method,
This is a preferable method because the adjustment of the diffusion element-containing layer is easy and the hard film is dense.

The method for producing a surface-coated sintered alloy having excellent adhesion according to the present invention is characterized in that a diffusion element-containing material is formed on at least one surface of a cemented carbide or a cermet-based sintered alloy containing a hard phase and a binder phase. A step of adhering or coating aluminum, silicon carbides, nitrides and oxides on the surface of the base material to which the substance containing a diffusion element is adhered or coated. And a second step of coating a hard film comprising a single layer or a laminate of two or more layers selected from these mutual solid solutions.

In the base material prepared in the method of the present invention, if at least one surface of the base material is a sintered surface, a polishing lap surface, an electropolished surface or a chemically etched surface, no deteriorated layer remains and the base material does not remain. This is preferable because the material, the diffusion element-containing layer, and the hard film have excellent mutual adhesion.

If the surface of the base material for coating the hard film is electropolished before the first step, defects such as a deteriorated layer are removed, and the base material is diffused. This is preferable because it is excellent in mutual adhesion between the element-containing layer and the hard film, and excellent in peeling resistance of the hard film and the diffusion element-containing layer.

When the diffusion element-containing substance in the first step is made of an element forming the diffusion element-containing layer, the diffusion element-containing substance is an element forming the diffusion element-containing layer and diffusing other elements forming the diffusion element-containing layer. It may be made of an element that also has a promoting role. Specifically, the diffusion element-containing substance is an iron group metal of Co, Ni, Fe, a (Co, Cr) alloy, a (Ni, Cr) alloy, a (Co, W) alloy, a (Co, W) alloy,
Examples thereof include at least one of the iron group element-containing substances represented by W) C compounds and (Ni, W) C compounds.

The material containing the diffusing element can be formed by electroplating, electroless plating, vacuum deposition (PVD), gas phase reactive plating (C
VD), chemical coating methods such as colloid coating and solution coating,
Formed by at least one of mechanical coating methods such as blast processing and shot processing using a shot material mainly containing iron and a metal of the iron group or a mixture of the shot material and a polishing material or an abrasive material. It is. Among these, the diffusion element-containing layer is formed by adhering or covering the base material surface with the iron-group element-containing layer-forming material containing the iron-group metal and / or the iron-group element-containing material as a main component. Can be.

When a hard film is coated on the surface of the base material to which the substance containing the diffusion element is adhered or coated, chemical vapor deposition, physical vapor deposition, plasma chemical vapor deposition, ion implantation,
It can be performed by at least one of an ion beam method, an ion irradiation method, and a laser deposition method.

[0029]

The surface-coated sintered alloy of the present invention, which has excellent adhesion,
The diffusion element-containing layer has a mediating effect of improving the adhesion between the base material and the hard film, and among these, the diffusion element-containing layer immediately above the hard phase particles of the base material at the interface is particularly suitable for the base material and the hard film. And has a function of remarkably improving the adhesiveness with the adhesive. Further, in the method for producing a surface-coated sintered alloy having excellent adhesion according to the present invention, the diffusion element-containing substance acts to promote the formation of the diffusion element-containing layer, and in particular, the iron group element-containing layer forms a uniform diffusion element-containing layer. It is acting.

[0030]

[Test 1] 86.0WC-1.5TiC-0.5T
Using a chip material with a breaker in the form of CNMG120408 according to the ISO standard prepared from a composition of iN-4.0TaC-8.0Co (% by weight), and a boss surface of 270 #
And a cutting edge of 320 mm with a nylon brush containing silicon carbide abrasive grains.
Honing processing of 04 mm was performed to obtain a cemented carbide base material chip. Using the base material chips thus obtained, the surface of each base material chip is surface-treated according to the surface treatment method and surface treatment conditions shown in Table 1, and ultrasonically cleaned in acetone. 1.0μm T from the side
iN first layer, 8.0 μm columnar TiCN second layer,
A hard film composed of a laminated layer having a total thickness of 11.0 μm including a third layer of Al ₂ O _{3 of} 5 μm and a fourth layer of TiN of 0.5 μm is coated, and the surfaces of the inventive products 1 to 8 and comparative products 1 to 5 A coated sintered alloy chip was obtained.

Each of the thus obtained inventive products 1 to 8 was 1
After cutting around the corners to make a thin plate, and cutting out the portion near the interface between the base material and the hard film of the cutting edge (brushed surface) and the breaker (sintered surface), lap polishing and electrolytic Polishing treatment was performed to prepare a measurement sample for a transmission electron microscope. For each sample, WC and (W, Ti, T) which are the hard phase of the base material at the interface between the base material and the hard film
a) The contents of Co (including Ni) and W, which are diffusion elements existing in the diffusion element-containing layer immediately above the (C, N) particles, were measured. Table 2 shows the results of the cutting edge portion, and Table 3 shows the results of the breaker portion. As is clear from Table 3, the present invention products 1 to 8 had a diffusion element-containing layer formed immediately above the base material hard phase and the binder phase at the interface between the base material and the hard film.

The comparative products 1 to 5 were also examined in the same manner. As a result, the diffusion at the interface between the base material and the hard film immediately above the WC and (W, Ti, Ta) (C, N) particles in the base material was observed. The element-containing layer was not confirmed, and the contents of Co (including Ni) and W, which are diffusion elements existing at a position on the hard film side at a distance of about 0.2 μm from the interface, were measured. Similarly, the measurement results at each of the ten locations are shown in Tables 2 and 3 as a measurement value range. Comparative products 1 to 5 have almost Co and W directly above the hard phase particles.
Was not detected, and was not uniform on the surface of the base material. When the hard film near the interface was analyzed, Co and W were found to vary greatly from 0 to 10 atomic%.

These inventive products 1 to 8 and comparative products 1 to
Regarding the sample No. 5, the vicinity of the interface between the base material and the hard film was observed with a field emission type scanning electron microscope using the above-described sample whose lap surface was lap-polished. Co (N) on hard phase particles
i) layer thickness, cracks in hard phase particles, 0.2
Table 2 and Table 3 show the measurement results of the hard phase fine particles of μm or less.
It was also described in.

Next, products 1 to 8 of the present invention and comparative products 1 to 5
Using five pieces of each surface-coated sintered alloy chip of the same shape that have not been cut, a work material: S45C with four grooves, a cutting speed: 150 m / min, a cutting depth: 2.0 mm, a feed: 0. An outer peripheral intermittent turning test was performed under a wet condition of 30 mm / rev. The test results show the ratio of the number of chips with chipped edges before the number of impacts due to intermittent cutting to 10,000, the number of chips with film separation (chipping) that reached 10,000, and the number of normal chips. The results are shown in FIG.

Further, the products 1 to 8 of the present invention and the comparative products 1 to
For No. 5, a disc of work material: S48C (150 φ × 30 m) was formed using one surface-coated sintered alloy chip having the same shape.
m), cutting speed: 50 to 180 m / min, cutting depth:
An intermittent turning test of the plate surface was performed under the conditions of 2.0 mm, feed: 0.30 mm / rev, and wet type. As the cutting edge damage after machining 50 surfaces, the average wear amount on the flank surface and the maximum width of crater wear on the rake surface were measured, and are also shown in Table 4.

[0036]

[Table 1]

[0037]

[Table 2]

[0038]

[Table 3]

[0039]

[Table 4]

[0040]

[Test 2] 88.0WC-2.0TaC-10.0
Using a chip material of SNGN120408 shape according to ISO standard prepared from the composition of Co (% by weight), the upper and lower surfaces and the outer peripheral surface are ground with a 270 # diamond grindstone, and the cutting edge portion is −25 ° × with a 400 # diamond grindstone.
Honing of 0.10 mm was performed to obtain a cemented carbide base material chip. The base material chips thus obtained were subjected to a surface treatment under the same conditions as those of the products 2, 5, 7, and 8 of the present invention described in Table 1 of the test 1, and the base materials for the products 9 to 12 of the present invention, respectively. And Similarly, surface treatment was performed under the same conditions as Comparative Products 1, 2, and 4 to obtain base materials for Comparative Products 6 to 8, respectively.

Inventive products 9 to 12 thus obtained and comparison
After ultrasonic cleaning each base material for articles 6 to 8 in acetone,
0.5μ from the base material side using CVD coating equipment
m-thick TiN first layer, 3.5 μm columnar TiCN
2-layer, 0.5 μm thick Al _TwoO_ThreeThird layer, 0.5 μm film
The total thickness of the fourth TiN layer is 5.0 μm.
Tables of the present invention products 9 to 12 and comparative products 6 to 8 covered with a hard film.
A surface-coated cemented carbide chip was obtained. Invention product 9 thus obtained
Rake surface of 12 to 12 and comparative product 6 to 8 chips
And a transmission electron microscope and a field emission type
Analysis and observation using a scanning electron microscope, and the results
The results are shown in Table 5.

Next, using the products 9 to 12 of the present invention and the comparative products 6 to 8 chips, a work material: SCM440 (work surface shape: 5)
0W × 200L), a cutting speed: 135 m / min, a depth of cut: 2.0 mm, a feed: 0.36 mm / blade, and a milling cutting test were performed under dry conditions. The evaluation of this cutting test
At the time of 40 pass machining, the tip edge was observed, and the number of thermal cracks generated on the rake face, the film peeling area at the crater, the average wear amount of the flank, and the state of micro chipping at the edge were determined. The results are shown in Table 6.

[0043]

[Table 5]

[0044]

[Table 6]

[0045]

[Test 3] A commercially available cemented carbide solid drill (6 mm) was used as a base material, and this base material was used under the same conditions as those of the products 2 and 8 of the present invention and the comparison product 1 described in Table 1 of Test 1. Surface treatment was applied. These were ultrasonically cleaned in acetone and then 3.0 μm thick using a CVD coating apparatus.
, And surface-coated cemented carbide drills of inventive products 13 and 14 and comparative product 9 were obtained. As a result of analyzing the Co and W contents of the outer peripheral cutting edge portion of each drill in the same manner as in the test 1, Co = 8 to 11 at for the product 13 of the present invention
%, W = 9 to 12 at%, and Co = 5 in the product 14 of the present invention.
8 at%, W = 5 to 9 at%, Comparative product 9 has Co = 1 to 9 at%
6 at% and W = 0 to 8 at%.

Workpiece: Pre-hardened steel (HRC = 4) using drills of inventive products 13 and 14 and comparative product 9
0), cutting speed: 30 m / min, depth of cut: 10 mm,
Table feed: 64 mm, feed per blade: 0.02 mm /
Groove processing test is performed under the condition of blade and wet type, cutting length is 50m
At the point of time, the flank wear width of the cutting edge was measured. as a result,
The wear width of the product 13 of the present invention was 0.05 mm and the wear width of the product 14 of the present invention was 0.07 mm, whereas the wear width of the comparative product 9 was 0.10 mm.

[0047]

[Test 4] Approximately 10φmm × 60mm commercially available
Using a cemented carbide material for wear-resistant tools (equivalent to V30 according to JIS) as a base material, the entire surface of the base material was rough- and finish-ground with 140 # and 800 # diamond grindstones to produce punches for punching. Then, it processed by the same conditions as the product 2 of this invention described in Table 1 of the execution test 1, and obtained the base material for the product 15 of this invention. This and an untreated comparative product 10 punch were ultrasonically cleaned in acetone, and then a 0.5 μm-thick TiN first layer was formed from the base material side using a CVD coating apparatus.
A total of 4.0 μm formed by laminating a 3.5 μm thick TiC second layer
A hard film having a thickness of m was coated to obtain surface-coated cemented carbide punches of product 15 of the present invention and comparative product 10.

Using the product 15 of the present invention and the comparative product 10, a zinc steel plate having a thickness of 0.6 mm was punched out, and the number of shots until a defective product was generated due to burrs was measured. As a result, the product 15 of the present invention had about 1.1 million shots, while the comparative product 10 had about 350,000 shots.
Further, the vicinity of the interface between the product 15 of the present invention and the comparative product 10 was examined in the same manner as in the test 1, and as a result, the product 15 of the present invention was
Was almost the same as the product 2 of the present invention, and the comparative product 10 was almost the same as the comparative product 1.

[0049]

According to the surface-coated sintered alloy of the present invention, the diffusion element is uniformly dispersed immediately above the base material hard phase and the binder phase at the interface between the base material and the hard film, and particularly, directly above the hard phase. A conventional surface-coated sintered alloy in which a diffusion element-containing layer that is uniformly dispersed and mixed in the film is formed, and the diffusion element is non-uniformly contained and almost no diffusion element exists directly above the base metal hard phase at the interface. The adhesion between the hard film and the base material is greatly improved compared to the comparative product consisting of: as a result, for example, cutting tools such as turning tools, milling tools, drills, end mills, and other dies, When used as a wear-resistant tool such as a cutting tool such as a slitter or a cutting blade from a punch tool or other mold tool, the excellent effect of reducing damage due to film peeling and obtaining a stable and long life with little variation is exhibited. Sa Is shall.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4K029 AA04 BA54 BA55 BA60 BB02 BC00 BD05 4K044 AA09 AB08 BA12 BA18 BB02 BC05 CA04 CA07 CA12 CA13 CA14 CA18 CA51 CA53

Claims (17)

[Claims] 1. A cemented carbide or a cermet-containing sintered alloy containing a hard phase and a binder phase is used as a base material, and a group 4a, 5a, or 6a element of the periodic table, aluminum or silicon is formed on the surface of the base material. A surface-coated sintered alloy coated with a hard film composed of a single layer or a laminate of two or more layers selected from carbides, nitrides, oxides, and mutual solid solutions thereof; A diffusion element-containing layer in which at least one type of diffusion element different from the element constituting the hard film is almost uniformly diffused in the hard film coated at least on the hard phase particles at the interface with the hard film. Surface-coated sintered alloy with excellent adhesion formed. 2. The base material is made of a cemented carbide, and the hard phase is made of tungsten carbide, or tungsten carbide and carbides, nitrides, carbonates, and nitroxides of elements of groups 4a, 5a and 6a of the periodic table. 2. The surface coating having excellent adhesion according to claim 1, wherein the surface coating comprises at least one cubic structure compound selected from these mutual solid solutions, and the binder phase contains cobalt and / or nickel as a main component. Sintered alloy. 3. The hard film according to claim 1, wherein the first layer coated adjacent to the base material is one of a titanium-containing nitride, carbide, and carbonitride. Surface-coated sintered alloy with excellent adhesion. 4. The surface-coated sintered alloy having excellent adhesion according to claim 1, wherein the diffusion element includes at least an element constituting the base material. 5. The sintered alloy according to claim 1, wherein the diffusion element is at least one of iron group elements, tungsten and carbon. 6. The adhesion according to claim 1, wherein the diffusion element has an average content of each of the iron group element and tungsten in the diffusion element containing layer of at least 3 to 15 at%. Surface coated sintered alloy with excellent properties. 7. The hard element according to claim 1, wherein the diffusion element-containing layer has a structure in which at least one kind of iron group element and tungsten and carbon are mixed carbides, or the composite carbides are mixed in the hard film. 7. The surface-coated sintered alloy according to any one of the above items 6, which is excellent in adhesion. 8. The method according to claim 1, wherein the diffusion element-containing layer is formed immediately above a hard phase and a binder phase of the base material at an interface between the base material and the hard film. A surface-coated sintered alloy with excellent adhesion as described. 9. The adhesion according to claim 1, wherein an iron group metal layer having an average thickness of 0.5 μm or less exists at an interface between the base material and the diffusion element-containing layer. Excellent surface-coated sintered alloy. 10. The surface of the base material at the interface between the base material and the diffusion element-containing layer has hard phase particles of 0.2 μm or more and has no cracks in the hard phase particles. The surface-coated sintered alloy according to any one of claims 1 to 9, which has excellent adhesion. 11. A first step of adhering or coating a diffusion element-containing substance on at least one surface of a base material of a cemented carbide or a cermet-containing sintered alloy containing a hard phase and a binder phase, and the diffusion element-containing substance On the surface of the base material on which is adhered or coated, one kind of element selected from the elements of groups 4a, 5a and 6a of the periodic table, aluminum, silicon carbide, nitride, oxide and their mutual solid solution. A method for producing a surface-coated sintered alloy having excellent adhesion, which is produced through at least a step comprising a second step of coating a hard film composed of two or more layers. 12. The adhesive material according to claim 11, wherein at least one surface of said base material is at least one of a sintered surface, a polished surface, a lap surface, an electropolished surface, and a chemically etched surface. Excellent surface coated sintered alloy manufacturing method. 13. The surface-coated sintered alloy having excellent adhesion according to claim 11, wherein at least one surface of the base material is subjected to electrolytic polishing before the first step. Recipe. 14. The method according to claim 11, wherein said diffusion element-containing substance is made of an iron group metal and / or an iron group element-containing substance.
The method for producing a surface-coated sintered alloy having excellent adhesion according to any one of the above items. 15. The method according to claim 15, wherein the diffusing element-containing material is an electroplating method, an electroless plating method, a vacuum evaporation method, a physical evaporation method, a chemical evaporation method, a colloid coating method, a solution coating method, a shot processing method,
The method for producing a surface-coated sintered alloy having excellent adhesion according to any one of claims 11 to 14, wherein the surface-coated sintered alloy is adhered or coated by a base material surface treatment using at least one of blasting methods. 16. The method according to claim 16, wherein the surface treatment of the base material comprises an iron group metal and / or
The method according to claim 15, which is performed by a blast treatment method or a shot treatment method using an iron-group element-containing layer-forming substance containing an iron-group element-containing substance as a main component or a mixture of the iron-element-containing layer-forming substance and a polishing material. A method for producing a surface-coated sintered alloy having excellent adhesion as described above. 17. The hard film is coated by at least one of chemical vapor deposition, physical vapor deposition, plasma chemical vapor deposition, ion implantation, ion beam, ion irradiation, and laser vapor deposition. Any one of claims 11 to 16
A method for producing a surface-coated sintered alloy having excellent adhesiveness according to the above item.