JP2004291039A - Bonding method for cemented carbide member and diamond member, bonding structure, cutting blade chip for drilling tool, cutting blade member, and drilling tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bonding method for bonding a member made of cemented carbide and a member made of diamond having an excellent heat resistance, a bonding structure, a cutting blade chip for drilling tool, a cutting blade member, and a drilling tool. <P>SOLUTION: The cutting blade chip used for the cutting blade of the drilling tool has a structure comprising a cutting blade body part 11 made of the cemented carbide (the cemented carbide member), the member 12 made of diamond supported by the cutting blade body part 11, and a metal layer 13 that is arranged between the cutting blade body part 11 and the diamond member 12 and diffusion-bonded with them respectively. The metal layer 13 is composed of one kind of metal among Mo, Cr and Hf, or an alloy made from two or more kinds among these metals. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a joining method and a joining structure of a cemented carbide member and a diamond member, and a cutting piece, a cutting member, and a cutting tool of a drilling tool used for excavating a well.
[0002]
[Prior art]
Drilling tools used for drilling wells for underground resource development and investigation wells for investigating the underground environment include a plurality of tungsten carbide-based cemented carbides on the tip surface of the alloy steel tool body. Posts made of carbide (hereinafter referred to as “carbide posts”) are fixed in a predetermined arrangement by means such as brazing or shrink-fitting. An excavation tool having a structure in which a cutting piece made of a knotted diamond is directly brazed is known.
In this excavation tool, the tool body is attached to the tip of the pipe, and the tool body is rotated while applying a load in the excavation direction to the tool body via the pipe, so that the excavation is performed by the cutting blade piece provided in the tool body. Is what you do.
[0003]
Here, diamond has poor wettability and is difficult to braze with a normal brazing material. Therefore, in this drilling tool, for example, Cu (copper): 20 to 40% by mass, Ti (titanium): 0.5 to 10 The cutting edge piece is brazed to the carbide post by using an Au alloy brazing material (melting point: 940 ° C.) having a composition containing Au (gold) and unavoidable impurities, the balance being Au (gold). See, for example, Patent Document 1.
[0004]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 2000-000686
[Problems to be solved by the invention]
In recent years, in order to secure energy sources other than fossil fuels and nuclear power generation, there is an increasing demand for the development of geothermal-based energy sources such as geothermal power generation. However, in order to utilize geothermal energy, it is necessary to excavate to a high-temperature geological formation, and therefore, an excavation tool that can withstand such high temperatures is required.
In addition, fossil fuels are almost completely exhausted in the area near the ground surface where they can be easily mined, and it is necessary to excavate to a greater depth (for example, 5000 m underground) when newly mining fossil fuels. . Such deep formations are hot because of their proximity to the mantle, and excavating such high-temperature formations requires excavating tools that can withstand high temperatures.
[0006]
However, in the conventional drilling tool, the cemented carbide post and the cutting piece made of sintered diamond are joined by brazing as described above, and the heat-resistant temperature of the brazing material is not so high. When such a high-temperature stratum is excavated, there is a possibility that the brazing material for brazing the cutting piece is melted, the cutting piece is peeled off from the carbide post, or the joint is deformed.
For this reason, conventionally, it has not been possible to excavate a stratum having a very high temperature.
[0007]
The present invention has been made in view of such circumstances, and has a method of joining a cemented carbide member and a diamond member having excellent heat resistance, a joining structure, a cutting piece of a drilling tool, and a cutting member. And drilling tools.
[0008]
[Means for Solving the Problems]
The method for joining a cemented carbide member and a diamond member according to the present invention is a method for joining a cemented carbide member and a diamond member between Mo (molybdenum), Cr (chromium), and Hf (hafnium). Any one kind of metal and metal foil composed of inevitable impurities, or a metal foil composed of an alloy of two or more of these metals and inevitable impurities, sandwiching the cemented carbide member and the diamond member, Each is characterized by being diffusion bonded to the metal foil.
[0009]
The diffusion bonding between the cemented carbide member and the diamond member and the metal foil is performed under the condition that the metal foil is sandwiched between the cemented carbide member and the diamond member under an ultra-high pressure of, for example, 5 to 6 GPa. It is performed by performing an ultra-high temperature heat treatment of １５1550 ° C.
Here, since Mo, Cr, and Hf constituting the metal foil are not all catalytic metals used for sintering diamond, even if the above heat treatment is performed, only a part of the metal foil is made of a cemented carbide member. The metal foil is diffused into the diamond member, and most of the metal foil remains as it is between the cemented carbide member and the diamond member to form a metal layer therebetween. In addition, since the metal or alloy constituting the metal foil is not a catalytic metal as described above, the metal or alloy diffuses only in the vicinity of the joint with the metal foil in the diamond member, and does not adversely affect the physical properties of the diamond member. .
[0010]
By performing diffusion bonding in this manner, a diffusion layer in which the components of the metal foil are diffused is formed in the vicinity of the bonding portion between the diamond member and the metal foil, and the diamond member and the metal foil are firmly connected. Joined.
Also, in the cemented carbide member, a diffusion layer in which the components of the metal foil are diffused is formed near the joint with the metal foil, so that the cemented carbide member and the metal foil are firmly joined. You.
Furthermore, since the metal or alloy composing the metal foil has a higher melting point and higher heat resistance than conventionally used brazing materials, the joining structure obtained by this joining method is a conventional joining structure by brazing. It has higher heat resistance.
[0011]
Here, the heat-shrinkage rate differs between the cemented carbide member and the diamond member, but a metal layer is formed between them, and this metal layer acts as a stress buffer, so that after the above-mentioned heat treatment, it is at room temperature. When returning to normal pressure, the stress stored in the cemented carbide member and the diamond member will be absorbed by the metal layer, and it will be difficult for the stress to concentrate on the diamond member, and cracks and the like will occur in the diamond member. It hardly occurs, and the hard metal alloy member and the diamond member hardly peel off.
[0012]
The joining structure between the cemented carbide member and the diamond member according to the present invention is such that, between the cemented carbide member and the diamond member, any one of Mo, Cr, and Hf metal and inevitable impurities A metal layer composed of an alloy of two or more of these metals and inevitable impurities is provided, and the cemented carbide member and the diamond member are respectively diffusion bonded to the metal layer. It is characterized by having.
In the joining structure between the cemented carbide member and the diamond member, the metal layer for joining the cemented carbide member and the diamond member has a higher melting point and higher heat resistance than conventionally used brazing materials. Since it is made of a metal or an alloy thereof, it has higher heat resistance than a conventional joint structure. Also, the joining strength between the cemented carbide member and the diamond member is high.
[0013]
The cutting piece of the excavating tool according to the present invention is a cutting piece attached to a post provided on the tip end surface of the tool body of the excavating tool to constitute a cutting edge of the excavating tool, and A cemented carbide cutting blade base constituting a joint, and a diamond member supported by the cutting blade base, wherein Mo, Cr, A metal layer composed of any one of Hf metal and unavoidable impurities, or a metal layer composed of an alloy of two or more of these metals and unavoidable impurities is provided; Each member is diffusion-bonded to the metal layer.
[0014]
In the cutting blade piece of the drilling tool thus configured, a metal layer is provided between the cutting blade base and the diamond member, and the cutting base and the diamond member are diffusion-bonded to the metal layer. Therefore, the bonding strength of the diamond member to the cutting blade base is extremely high.
Furthermore, since the metal or its alloy constituting the metal layer has a higher melting point and higher heat resistance than conventionally used brazing materials, this cutting edge piece is higher than the conventional cutting edge piece. Has heat resistance.
[0015]
In the cutting piece of this excavation tool, the diamond member may be made of a high heat resistant sintered diamond using magnesium carbonate (hereinafter, referred to as MgCO ₃ ) as a binder.
Here, the high heat resistant sintered diamond is obtained by sintering a diamond powder under an ultrahigh pressure of 7 to 8 GPa using, for example, MgCO ₃ as a binder at an ultrahigh temperature of 1800 to 2400 ° C. Things.
In this case, since the diamond member is made of high heat resistant diamond having more excellent heat resistance, the heat resistance of the cutting piece is further improved.
[0016]
A cutting blade member according to the present invention is a cutting blade member provided on a tip end surface of a tool main body of an excavating tool, and a cemented carbide post mounted on the tool main body, and mounted on the post. The drilling tool has a diamond cutting edge piece constituting a cutting edge, and between the post and the cutting edge piece, any one of Mo, Cr, and Hf metal and inevitable impurities. A metal layer made of an alloy of two or more of these metals and unavoidable impurities is provided, and the post and the cutting edge piece are each diffusion bonded to the metal layer. Features.
In the cutting blade member of the drilling tool configured as described above, the joining structure between the cemented carbide post and the diamond cutting blade piece has high heat resistance, and the joining strength is remarkably high.
[0017]
A cutting blade member according to the present invention is a cutting blade member provided on a tip end surface of a tool body of an excavating tool, and includes a post mounted on the tool main body, and a cutting device mounted on the post and cutting on the excavating tool. And a cutting edge piece constituting a blade, wherein the cutting edge piece is the cutting edge piece according to claim 3 or 4.
In the cutting blade member of the drilling tool configured as described above, a cutting piece having a high heat resistance and a remarkably high bonding strength of a bonding structure between a cemented carbide cutting blade base and a diamond member is used as a cutting blade. Can be
[0018]
The excavating tool according to the present invention is an excavating tool in which a cutting blade member having a cutting blade piece mounted on a post is mounted on a tip end surface of a tool body, and the cutting blade piece is according to claim 3 or 4. Or a cutting blade member according to claim 5 or 6 is used as the cutting blade member.
In the drilling tool configured as described above, a cutting piece having a high heat resistance and a remarkably high joining strength of a joining structure between a cemented carbide cutting edge substrate and a diamond member, or a cemented carbide post is used. Excavation is performed using a cutting blade member having a high heat resistance of a bonding structure with a diamond cutting blade piece and a remarkably high bonding strength.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the present embodiment, the joining method and joining structure between a cemented carbide member and a diamond member according to the present invention are applied to a cutting blade of a drilling tool.
Here, FIG. 1 is a perspective view schematically showing a configuration of the excavating tool according to the present embodiment, and FIG. 2 is a schematic diagram showing a configuration of a cutting blade member constituting the excavating tool according to the present embodiment. FIG. 3 is a perspective view schematically showing the configuration of the cutting blade according to the present embodiment, and FIG. 4 is a cross-sectional view showing the structure of the cutting blade according to the present embodiment.
[0020]
The excavating tool 1 according to the present embodiment includes a substantially disk-shaped tool body 2 made of alloy steel or the like specified in JIS SCH415, and a plurality of cutting blade members 3 provided in a predetermined arrangement on the tip end surface of the tool body 2. have. The cutting blade member 3 is attached to the tool body 2 by means such as brazing or shrink fitting.
The cutting blade member 3 includes a cemented carbide post 6 having a columnar shape and made of cemented carbide, and a cutting blade piece 7 attached to a side of the cemented carbide post 6 facing the excavation direction by brazing or the like. In the present embodiment, cemented carbide post 6 is made of a general tungsten carbide-based cemented carbide.
[0021]
The cutting blade piece 7 has a cutting blade base 11 made of a cemented carbide which forms a joint portion with the carbide post 6, and a diamond member 12 supported by the cutting blade base 11. A metal layer 13 is provided between the substrate 11 and the diamond member 12, and the cutting blade substrate 11 and the diamond member 12 are respectively diffusion bonded to the metal layer 13.
[0022]
The cutting blade base 11 is formed in a substantially disk shape, one surface of which is a brazing surface to be brazed to the carbide post 6, and the other surface facing the one surface (that is, the surface facing the excavation direction). A cutout-shaped concave portion is formed on the (side) side, and this concave portion serves as a mounting seat 11 a for mounting the diamond member 12. The mounting seat 11a has the same shape as the outer shape of the diamond member 12, and is provided in a region of the cutting blade piece 7 where wear is likely to occur during excavation work. In the present embodiment, the mounting seat 11a has a fan shape in plan view.
The cutting blade base 11 is made of a tungsten carbide-based cemented carbide using Co (cobalt) as a binder, that is, a common cemented carbide. In the present embodiment, the cutting edge substrate 11 is made of a cemented carbide containing 10% by mass of Co as a binder and the remainder being WC (tungsten carbide) and unavoidable impurities. Since the cemented carbide has high strength and high toughness, the cutting blade base 11 made of the ultra-high alloy acts as a shock absorber for absorbing the thermal and mechanical shock applied during the excavation work at the cutting blade piece 7. .
[0023]
The diamond member 12 is provided in an area of the cutting blade piece 7 where wear is likely to occur during excavation work. In the present embodiment, the ratio of the diamond member 12 to the front surface of the cutting blade 7 is set to 25 to 60 area%.
Here, the diamond member 12 is composed of a normal sintered diamond alone or a single highly heat-resistant sintered diamond having more excellent heat resistance. Or a composite of In the present embodiment, the diamond member 12 is composed of a single piece of heat-resistant sintered diamond alone.
[0024]
The metal layer 13 provided between the cutting edge substrate 11 and the diamond member 12 is made of any one of Mo, Cr, and Hf and inevitable impurities, or an alloy of two or more of these metals. It consists of unavoidable impurities. In the present embodiment, the metal layer 13 is made of a foil made of Mo, and the thickness D is set to 0.02 to 0.1 mm.
Here, Mo, Cr and Hf are all metals having extremely high melting points (Mo has a melting point of 2622 ° C., Cr has a melting point of 1905 ° C., and Hf has a melting point of 2207 ° C.), and has excellent heat resistance. ing. Similarly, these alloys also have a very high melting point and excellent heat resistance.
[0025]
The cutting blade piece 7 configured as described above is created as follows.
First, the cutting blade base 11 and the diamond member 12 are manufactured in desired shapes.
The cutting blade base 11 is manufactured in the same manner as a normal cemented carbide product. For example, by forming and sintering a raw material powder of a cemented carbide to form a disc-shaped cemented carbide chip, and performing cutting or the like on one surface side of the cemented carbide chip to form the mounting seat 11a, It is obtained by molding and sintering a raw material powder of a cemented carbide into a disk shape having a mounting seat 11a.
[0026]
The diamond member 12 is produced using, as raw material powders, diamond powder having an average particle diameter of 10 μm and a purity of 99.9% or more, and MgCO ₃ powder having an average particle diameter of 10 μm and a purity of 95% or more.
First, MgCO ₃ powder is press-molded at a pressure of 100 MPa to obtain a green compact having a desired shape. Subsequently, the green compact is charged into a Ta (tantalum) capsule, and then the diamond powder is filled on the green compact in the capsule.
In this state, by performing an ultra high pressure sintering was charged in a (carbide sintering device used in the conventional sintered diamond fabrication) capsule belt type super high pressure sintering apparatus, 4.0 wt% of MgCO ₃ To obtain a block of sintered diamond.
In the present embodiment, the ultra-high pressure sintering is performed by heating to 2250 ° C. and maintaining the pressure for 30 minutes while applying a pressure of 7.7 Gpa.
Then, the block of the sintered diamond is polished with a diamond grindstone to be roughly shaped, and then a diamond piece having a desired shape is further cut out by laser processing to obtain the diamond member 12.
[0027]
Subsequently, a metal foil made of any one of Mo, Cr, and Hf and an unavoidable impurity, or a metal foil between them, between the cutting blade base 11 and the diamond member 12 obtained as described above. With a metal foil (having a thickness of 0.02 to 0.1 mm) made of an alloy of two or more metals and unavoidable impurities, the diamond member 12 is fitted to the mounting seat 11a of the cutting blade base 11. Put in.
Further, the cutting blade base body 11, the metal foil, and the diamond member 12 temporarily assembled as described above are loaded into a belt-type ultra-high pressure sintering apparatus, subjected to an ultra-high temperature and high pressure heat treatment, and these members are joined. The cutting blade piece 7 according to the present invention is obtained by being integrated. In the present embodiment, the heat treatment at the ultra-high temperature and high pressure is performed by heating to 1500 ° C. under a pressure of 5.5 GPa and holding for 30 minutes.
[0028]
By this heat treatment, the components of the metal foil diffuse into the cutting blade base 11 and the diamond member 12, respectively, and the components constituting the metal foil diffuse near the interface with the metal foil in the cutting blade base 11 and the diamond member 12. Thus, the super-high-pressure heat melting diffusion layers S1 and S2 are formed.
Here, since Mo, Cr, and Hf constituting the metal foil are not all catalytic metals used for sintering diamond, only a part of the metal foil is subjected to the cutting edge substrate 11 and the diamond even if the above heat treatment is performed. Most of the metal foil remains as it is between the cutting edge substrate 11 and the diamond member 12 to form the metal layer 13 therebetween. In addition, since the metal or alloy constituting the metal foil is not a catalytic metal as described above, the metal or alloy diffuses only in the vicinity of the joint with the metal foil in the diamond member 12, which adversely affects the physical properties of the diamond member 12. Do not give.
[0029]
Among the ultrahigh-pressure heat-fusion diffusion layers S1 and S2, the ultrahigh-pressure heat-fusion diffusion layer S1 formed on the cutting edge base 11 extends from the joint surface with the metal layer 13 to a depth of 0.1 to 0.5 mm. The ultra-high pressure heat melting diffusion layer S2 formed on the diamond member 12 is formed over a depth of 0.01 to 0.1 mm from a bonding surface with the metal layer 13.
Due to the presence of the ultrahigh-pressure heat-melting diffusion layer, the cutting edge substrate 11 and the diamond member 12 are respectively strongly bonded to the metal layer 13.
The state of the ultrahigh-pressure heat-melting diffusion layers S1 and S2 and the formation range thereof can be examined by observing the structure using a metallographic microscope.
[0030]
Here, the cutting blade base 11 and the diamond member 12 have different heat shrinkage rates, but a metal layer 13 is formed between them, and since the metal layer 13 acts as a stress buffer, When returning to normal temperature and normal pressure later, the stress stored in the cutting blade base 11 and the diamond member 12 is absorbed by the metal layer 13, so that stress is less likely to concentrate on the diamond member 12 and the diamond member Cracks and the like are not easily generated in the cutting blade base 12 and the diamond member 12 is hardly separated from the cutting blade base 11.
[0031]
The cutting blade piece 7 thus obtained is brazed to the carbide post 6 to form the cutting blade member 3. The cutting tool 3 is mounted on the tool body 2 to obtain the excavating tool 1.
[0032]
The excavating tool 1 thus configured is used for excavating work in the same manner as a conventional excavating tool.
In this excavating tool 1, the cutting blade base 11 and the diamond member 12 are firmly joined at the cutting blade piece 7. Further, the metal or alloy constituting the metal layer 13 provided between the cutting blade base 11 and the diamond member 12 has a very high melting point and heat resistance as compared with the melting point of the conventional brazing material. The heat resistance of the joint structure between the diamond member 11 and the diamond member 12 is much higher than in the past, and excavation of a high-temperature formation that was impossible with a conventional drilling tool due to the problem of the heat resistance of the brazing material. Can be.
[0033]
Here, when high-speed excavation is performed, an extremely high thermal mechanical impact is applied to the cutting blade piece 7. The diamond member 12 itself used as the cutting blade piece 7 is extremely hard, but on the other hand, is brittle, so that a minute chip is likely to be generated when it receives a strong impact. In the diamond member 12, the progress of abrasion is remarkably promoted due to the generation of a minute chip, and as a result, the service life is reached in a relatively short time.
[0034]
According to the study of the present inventors, in the cutting tool 7, the wear caused by excavation progresses over the entire front surface of the cutting tool from the relation of the mounting position of the cutting tool 3 in the cutting tool 1. Instead, certain areas of the front face of the cutting edge are worn locally, and the remaining wear is only a small amount that follows this localized wear and the area where this localized wear occurs. Was found to be 25% by area or less of the front surface of the cutting blade piece.
Therefore, in the present embodiment, the diamond member 12 having excellent wear resistance is provided in a region where local wear occurs in the cutting blade piece 7, and the other portion is made of an ultra-high alloy having shock absorbing performance. It is constituted by a cutting blade base 11 made of. Thereby, while making it difficult for local wear of the cutting blade 7 to occur, the thermal mechanical shock applied to the cutting blade 7 at the time of excavation is absorbed by the cutting blade base 11, and the minute chipping of the diamond member 12 due to the shock is prevented. As a result, the life of the cutting blade piece 7 was improved.
[0035]
Here, when the ratio of the diamond member 12 to the front surface of the cutting edge piece is less than 25% by area, the cutting edge substrate 11 made of cemented carbide directly participates in excavation, and wear of the cutting edge substrate 11 progresses. Resulting in. On the other hand, when the ratio exceeds 60 area%, the ratio occupied by the cutting blade base 11 acting as the shock absorbing portion becomes relatively small, and the extremely high thermal mechanical shock generated in the high-speed rotation operation is sufficiently reduced. It cannot be absorbed, and as a result, the occurrence of minute cracks particularly in the diamond member 12 rapidly increases. For this reason, the ratio of the diamond member 12 occupying the front surface of the cutting piece 7 is preferably 25 to 60 area%, and more preferably 30 to 45 area%.
[0036]
In the above-described embodiment, the cutting blade piece 7 includes the cutting blade base 11 having the fan-shaped mounting seat 11a and the fan-shaped diamond member 12 made of heat-resistant sintered diamond. Without being limited, the member constituting the cutting blade piece 7 can have another arbitrary shape.
For example, as shown in FIG. 5A, the cutting blade piece 7 may have a configuration in which a plate-shaped cutting blade base 11 and a plate-shaped diamond member 12 are simply joined via a metal layer 13. Further, as shown in FIG. 5 (b), a part of the diamond member 12 is a high heat resistant diamond part 12a made of high heat resistant sintered diamond, and the remaining part is a sintered diamond made of normal sintered diamond. The structure may be a part 12b, or a structure in which a high heat resistant diamond part 12a is embedded in a sintered diamond part 12b as shown in FIG.
[0037]
Further, in the above-described embodiment, an example in which the joining method and the joining structure of the cemented carbide member and the diamond member according to the present invention are applied to the cutting blade piece 7 of the excavating tool 1 has been described. For example, as shown in FIG. 6, when the cutting piece 7a entirely made of normal sintered diamond or high heat-resistant diamond is used as the cutting piece as shown in FIG. May be applied to the joining between the cemented carbide post 6 and the cutting blade piece 7a.
[0038]
Further, the joining method and the joining structure of the cemented carbide member and the diamond member according to the present invention are not limited only to the above examples, and the cemented carbide member and the diamond member are not limited to the above examples. Any object can be applied as long as it can be joined.
[0039]
【The invention's effect】
According to the joining method and the joining structure of the cemented carbide member and the diamond member according to the present invention, the cemented carbide member and the diamond member have a high melting point and a high heat resistance provided between them. Since it is diffusion bonded to the metal layer, the heat resistance of the bonding structure between the cemented carbide member and the diamond member is significantly improved as compared with the conventional bonding structure by brazing.
[0040]
Further, according to the cutting blade of the excavating tool according to the present invention, the heat resistance of the joining portion between the cutting blade base and the diamond member constituting the cutting blade is remarkably increased, so that it is impossible in the past. Excavation of hot geological formations.
[0041]
Further, according to the cutting blade member of the present invention, since the heat resistance of the joint between the cutting blade piece and the post is remarkably enhanced, it is possible to excavate a high-temperature stratum which was conventionally impossible. .
[Brief description of the drawings]
FIG. 1 is a perspective view schematically showing a configuration of a drilling tool according to an embodiment of the present invention.
FIG. 2 is a side view schematically showing a configuration of a cutting blade member constituting the excavating tool shown in FIG.
FIG. 3 is a perspective view schematically showing a configuration of a cutting blade piece shown in FIG. 2;
FIG. 4 is a sectional view showing a structure of a cutting blade piece shown in FIG. 3;
FIG. 5 is a longitudinal sectional view showing another embodiment of the cutting blade piece according to the present invention.
FIG. 6 is a side view showing another embodiment of the cutting blade member according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Drilling tool 2 Tool main body 3 Cutting blade member 6 Carbide post (member made of cemented carbide)
7 Cutting edge piece 11 Cutting edge base (Carbide alloy member)
12 Diamond member 13 Metal layer (metal foil)

Claims (7)

A metal foil made of any one of Mo, Cr, and Hf and an unavoidable impurity, or an alloy of two or more of these metals is inevitable between a cemented carbide member and a diamond member. Sandwich metal foil made of impurities,
A method for joining a cemented carbide member and a diamond member, wherein the cemented carbide member and the diamond member are each diffusion bonded to the metal foil. A metal layer made of any one of Mo, Cr, and Hf and an unavoidable impurity, or an alloy of an alloy of two or more of these metals, between a cemented carbide member and a diamond member. A metal layer made of impurities is provided,
A joining structure between a cemented carbide member and a diamond member, wherein the cemented carbide member and the diamond member are each diffusion bonded to the metal layer. A cutting blade piece that is mounted on a post provided on a tip end surface of a tool body of the drilling tool and constitutes a cutting blade in the drilling tool,
A cemented carbide cutting blade base constituting a joint with the post,
Having a diamond member supported by the cutting blade substrate,
A metal layer composed of any one of Mo, Cr, and Hf and an unavoidable impurity, or an alloy of two or more of these metals, between the cutting blade base and the diamond member. A metal layer made of unavoidable impurities is provided,
The cutting blade piece of a drilling tool, wherein the cutting blade base and the diamond member are each diffusion bonded to the metal layer. The cutting edge piece of a drilling tool according to claim 3, wherein the diamond member is made of a high heat resistant sintered diamond using magnesium carbonate as a binder. A cutting blade member provided on a tip surface of a tool body of the excavating tool,
A cemented carbide post mounted on the tool body,
Having a diamond cutting blade piece mounted on the post and constituting a cutting blade in the excavating tool,
A metal layer composed of any one of Mo, Cr, and Hf and inevitable impurities, or an alloy of two or more of these metals and inevitable impurities is provided between the post and the cutting blade. A metal layer consisting of
The cutting member of a drilling tool, wherein the post and the cutting piece are respectively diffusion bonded to the metal layer. A cutting blade member provided on a tip surface of a tool body of the excavating tool,
A post attached to the tool body,
A cutting edge piece that is attached to the post and constitutes a cutting edge of the excavating tool,
A cutting blade member for an excavating tool, wherein the cutting blade piece is the cutting blade piece according to claim 3. An excavation tool to which a cutting blade member formed by mounting a cutting blade piece to a post is mounted on a tip surface of a tool body,
An excavating tool, wherein the cutting edge piece according to claim 3 or 4 is used as the cutting edge piece, or the cutting edge member according to claim 5 or 6 is used as the cutting edge member.

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