JPH04250906A - Polycrystal diamond machine tool and its manufacture - Google Patents

Abstract

PURPOSE:To restrict an occurrence of chipping in a cutting edge part during cutting edge work by means of grinding work by using a laminated body consisting of a polycrystal diamond layer and a base member as a material for a machine tool and conducting negative/and processing for formation of the cutting edge part. CONSTITUTION:The back surface of a base member is used as a face 6 of a machine tool, while a side surface of a polycrystal diamond layer is used as a flank of the machine tool. A negative land 10 is formed between the face 6 and the flank 7, thereby forming a cutting edge part 8 of the machine tool at the side surface of the polycrystal diamond layer.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polycrystalline diamond tool with excellent sharpness, which is ideal for finishing nonferrous metals and nonmetals, and a method for manufacturing the same.

0002

2. Description of the Related Art Diamond is used as cutting tools and wear-resistant tools because of its high hardness and high thermal conductivity. However, single-crystal diamond has the drawback of cleavage, and in order to suppress this drawback, for example,
As described in Japanese Patent No. 26, a diamond sintered body in which diamonds are sintered together using ultra-high pressure sintering technology has been developed.

However, since these diamond sintered bodies contain 5% to 10% of binder, they have had the problem that chipping occurs in the constituent particles.

[0004] Therefore, the inventors devised a cutting tool that uses polycrystalline diamond that does not contain a binder, that is, polycrystalline diamond that is constructed using a low-pressure gas phase method, as a tool material instead of a diamond sintered body. . An example of a cutting tool made of such polycrystalline diamond is shown in Japanese Patent Laid-Open No. 1-212767. FIG. 8 is a cross-sectional structural diagram showing an example of a polycrystalline diamond tool. In this polycrystalline diamond tool, a polycrystalline diamond tip 3 is fixed on the surface of a tool support 4 via a brazed portion 5. The chip 3 uses a polycrystalline diamond layer 2 synthesized using a low-pressure vapor phase method on the surface of a base material 1 such as silicon (Si). The chip 3 is fixed to the tool support 4 by brazing, with the polycrystalline diamond layer 2 formed on the surface of the base material 1. Thereafter, the base material 1 is removed by polishing to form a rake face 6, and the side surface of the polycrystalline diamond layer 2 is polished to form a flank 7, and further a cutting edge portion 8 is formed. .

[0005]

However, in a polycrystalline diamond tool as shown in FIG.
Problems arise in the grinding process to remove the blade and in the shaping process of the cutting edge. That is, in order to efficiently remove the base material 1, it is necessary to perform grinding using a diamond grindstone with a large grain size. However, when a grindstone with a large grain size is used, large chipping occurs at the cutting edge portion 8. Further, if a diamond grindstone with fine grain size is used to suppress this chipping, there arises a problem that processing time for removing the base material 1 increases, processing efficiency decreases, and cost increases.

[0006] Therefore, the present invention has been made to solve the above problems, and provides a polycrystalline diamond tool and a polycrystalline diamond tool that suppresses chipping that occurs at the cutting edge formed by grinding and has excellent machining efficiency. The purpose is to provide a manufacturing method thereof.

[0007]

[Means for solving the problem] Claims 1 to 7
The polycrystalline diamond tool according to the invention is composed of a laminate of a thin plate-like base material and a polycrystalline diamond layer synthesized on the surface of the base material by a low-pressure vapor phase method. The back surface of the base material serves as the rake surface of the tool, and the side surface of the polycrystalline diamond layer serves as the flank surface of the tool. moreover,
It is characterized in that the cutting edge of the tool is formed on the side surface of the polycrystalline diamond layer by forming a negative land between the rake face and the flank face.

[0008] Furthermore, the polycrystalline diamond tool according to the invention according to claims 8 to 16 includes a thin plate-like base material;
It has a tool material made of a laminate with a polycrystalline diamond layer synthesized on the surface of the base material by a low-pressure vapor phase method, and a tool support for supporting the tool material. Then, the tool material and the tool support are joined such that the growth surface of the polycrystalline diamond layer becomes the joint surface with the tool support. Furthermore, the back surface of the base material constitutes the rake surface of the tool, and the side surface of the polycrystalline diamond layer constitutes the flank surface of the tool. The tool is characterized in that a negative land is formed between the rake face and the flank face to form the cutting edge of the tool on the side surface of the polycrystalline diamond layer.

[0009] In the method for manufacturing a polycrystalline diamond tool according to claim 17, first, a polycrystalline diamond layer is formed on the surface of a base material by a low pressure vapor phase method. Next, the base material is polished to a predetermined thickness to form the rake face of the tool. Furthermore, a flank surface of the tool is formed on the side surface of the polycrystalline diamond layer. Then, a negative land is formed between the rake face and the flank face.

Furthermore, in the method for manufacturing polycrystalline diamond according to claim 18, first, a polycrystalline diamond layer is synthesized on the surface of a base material by a low-pressure vapor phase method. Next, the base material is polished to a predetermined thickness to form the rake face of the tool. Then, the tool material is joined to the tool support so that the growth surface of the polycrystalline diamond layer becomes the joining surface. Then, a flank surface of the tool is formed on the side surface of the polycrystalline diamond layer. Furthermore, a negative land is formed between the rake face and the flank face.

[0011]

[Operation] In the polycrystalline diamond tool according to claims 1 and 8, the base material remains on the surface of the polycrystalline diamond layer and is used as a rake face of the tool, thereby eliminating the need for removal of the base material. Efficiency can be improved. Further, by forming a negative land between the rake face and the flank face and forming the cutting edge on the side surface of the polycrystalline diamond layer, it is possible to form a cutting edge with excellent sharpness.

[0012] In the polycrystalline diamond tools according to claims 2 and 9, the negative land has an angle of 2° to 20° with respect to the rake face, and a width of 0.3 to 3 mm. If the angle of this negative land is set to 20 degrees or more, cutting resistance increases and the roughness of the finished surface decreases. Further, if the angle is defined to be less than 2 degrees, it becomes very difficult to process the cutting edge.

[0013] In the polycrystalline diamond tool according to claims 3 and 10, the cutting edge portion is formed at a position within 20 μm from the boundary position between the polycrystalline diamond layer and the base material along the direction perpendicular to the rake face. are doing. The position of this cutting edge is determined according to the shape of the negative land, and the cutting edge is formed on the side surface of the polycrystalline diamond layer. Thereby, the part of the fine diamond particles in the layer close to the substrate can be used as a cutting edge.

[0014] In the polycrystalline diamond tools according to claims 4 and 11, the magnitude of chipping at the cutting edge portion is 0.
It is formed to have a thickness of 5 to 5 μm. This improves the sharpness of the edge and enables fine processing.

[0015] In the polycrystalline diamond tool according to claims 5 and 12, the base material has a thickness of 0.1 to 1 mm. When the thickness of the base material is 1 mm or more, the discharge of chips becomes difficult, the welding of the cutting edge increases, and the roughness of the finished surface decreases. Furthermore, if the thickness of the base material is 0.1 mm or less, cracks are likely to occur during brazing treatment or cutting edge treatment.

[0016] The polycrystalline diamond tool according to claims 6 and 13 uses Si, SiC, Si3 as a base material.
It is made of one of N4, Mo, and W materials. Since these materials have similar linear expansion coefficients to polycrystalline diamond, the adhesion between the base material and the polycrystalline diamond layer is improved.

[0017] In the polycrystalline diamond tool according to claims 7 and 14, the polycrystalline diamond layer has a crystal grain size of 0.5 to 15 μm. If the grain size of the polycrystalline diamond layer is 15 μm or more, the toughness decreases, chipping increases during cutting, and edge breakage during cutting is likely to occur. Moreover, when the particle size is 0.5 μm or less, the wear resistance decreases.

[0018] In the polycrystalline diamond tool according to claim 15, the polycrystalline diamond layer has a thickness of 0.05 to 1 mm. If this thickness is 1 mm or more, the thickness will be excessive relative to the amount of wear when the polycrystalline diamond tool is used as a finishing tool. Further, if this thickness is 0.05 mm or less, cracks are likely to occur due to the bonding force during brazing.

[0019] In the polycrystalline diamond tool according to the sixteenth aspect, either cemented carbide or hard material is used as the tool support. This ensures the strength of the tool itself.

[0020] The method for manufacturing a polycrystalline diamond tool according to claims 17 and 18 allows the polycrystalline diamond tool to be efficiently manufactured using grinding.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure and manufacturing method of a polycrystalline diamond tool according to the present invention will be explained below with reference to FIGS. 1 to 6.

First, referring to FIG. 1, Si, SiC, S
i3 A polycrystalline diamond layer 2 is synthesized on the surface of a base material 1 made of any material such as N4, Mo, or W using a low-pressure vapor phase method. As the low-pressure gas phase method, a method in which thermionic radiation or plasma discharge is used to decompose and excite the raw material gas, or a film forming method using a combustion flame is effective. As the raw material gas, a mixed gas whose main components are hydrogen and hydrocarbons such as methane, ethane, and propane, alcohols such as methanol and ethanol, and organic carbon compounds such as esters is generally used. In addition to this, inert gases such as argon, carbon dioxide, water, etc. may also be contained in the raw material within a range that does not inhibit the diamond synthesis reaction or its properties. By such a low-pressure vapor phase method, polycrystalline diamond is formed on the surface of the base material 1 so that the average grain size thereof is 0.5 to 15 μm.

Next, referring to FIG. 2, the base material 1 is ground to a predetermined thickness using, for example, a diamond grindstone. The thickness of the base material 1 is set to about 0.1 to 1 mm. Thereafter, the base material 1 and the polycrystalline diamond layer 2 are cut by the laser beam 12 along a predetermined tool material shape. The tip 3 shown in FIG. 3 becomes the tip of a polycrystalline diamond tool. Note that if the polycrystalline diamond layer 2 is relatively thick, it can be used as a tool by directly forming a cutting edge and clamping it in a holder. In the following description, an example of a polycrystalline diamond tool fixed to a tool support will be described.

Referring to FIG. 4, polycrystalline diamond layer 2
It is fixed to the tool support 4 via the brazing part 5 so that the crystal growth surface of the tool becomes the bonding surface. The upper surface of the base material 1 constitutes the rake surface 6 of the tool. Note that the tool support 4 is made of cemented carbide, steel, or the like.

Further, referring to FIG. 5, polycrystalline diamond layer 2 is polished by grinding using a diamond grindstone or the like.
The side surface is ground into a predetermined shape. This forms the flank surface 7 of the tool.

Further, referring to FIG. 6, the vicinity of the intersection of the rake face 6 and flank face 7 is subjected to a negative land treatment by grinding to form a negative land 10. Generally, the slope newly formed by this grinding process is called the land portion 11, and the shape of the negative land 10 is defined by the angle θ between the land portion 11 and the rake face 6, and the width represented by the symbol L1 shown in the figure. . And the angle θ of this negative land part
is preferably 2 to 20 degrees, and the width L1 is preferably 0.3 to 3 mm. Further, it is preferable that the position L2 of the cutting edge portion 8 formed along the intersection line between the land portion 11 and the flank surface 7 is within 20 μm. Note that this position L2 is defined corresponding to the forming angle θ of the negative land 10.

[0027] In the polycrystalline diamond tool formed by such a process, chipping occurring at the cutting edge portion 8 can be suppressed to 0.5 to 5 μm. As shown in FIG. 7, the size of the chipping 9 formed on the cutting edge 8 is determined by the larger of the lengths X1 and Expressed using a value. As described above, chipping of the cutting edge portion 8 can be reduced because the base material 1 is coated with the polycrystalline diamond layer 2 in the machining process of the flank surface 7 shown in FIG. This is because it is possible to prevent the upper end of the holder from being notched due to polishing. Furthermore, in the negative land treatment step shown in FIG. 6, since the base material 1 is ground to a predetermined thickness, the negative land treatment can be performed using a fine diamond grindstone. If you use a fine diamond grindstone,
It is possible to suppress the occurrence of chipping when forming the cutting edge.

Next, a concrete example will be explained. (Example 1) Microwave plasma CVD (Chemical
A polycrystalline diamond layer was synthesized on a 2 mm thick Si substrate for 10 hours under the following conditions using the Al Vapor Deposition method.

As a result, the average crystal grain size was 5 μm and the thickness was 0.2 μm.
It was possible to recover polycrystalline diamond of mm. The thickness of the base material was reduced to 0.5 mm by grinding, and this was used as a tool material. This tool material was brazed to a cemented carbide shank so that the growth surface of the polycrystalline diamond layer served as the joint surface. After that, use a #800 diamond whetstone to grind the indexable tip (model number: S).
PGN120304) was produced. Furthermore, an angle of 10 degrees and a width of 2.
A negative land with a shape of 8 mm was formed, and a 5μ
A cutting edge portion was formed by exposing a polycrystalline diamond layer at position m. The finally obtained indexable tip (A
), the chipping of the cutting edge was good at 5 μm, and the time required for cutting was 5 minutes.

For comparison, the base material Si was dissolved and
A chip was made using only the removed polycrystalline diamond layer as a tool material. The tool material and the cemented carbide tool member were brazed so that the surface of the polycrystalline diamond layer on the base material side served as the joint surface. Then, when the conditions for sharpening were selected so that the quality of the cutting edge was the same as that of the tip (A), it became clear that a #2000 diamond grindstone could be used. This chip (
The time required for cutting B) was 30 minutes.

The performance of these indexable tips as finishing tools was evaluated under the following conditions.

(Cutting conditions) Work material: AC4C-T6 (Al-7%Si) round bar (Al: aluminum) Cutting speed: 500 m/min Depth of cut: 0.2 mm Feed rate: 0.1 mm/rev. Coolant: Water-soluble oil (evaluation method) Comparison of work surface roughness after 5 and 60 minutes of cutting.
As shown in Table 1, the tool (A) of the present invention can be manufactured in a shorter manufacturing time than the tool (B) manufactured by the conventional method, and can significantly reduce costs. Furthermore, it became clear that the tool performance was comparable and that a good machined surface could be obtained.

[0033]

[Table 1]

[0034]

[Effects of the Invention] As described above, the polycrystalline diamond tool according to the present invention uses a laminate of a polycrystalline diamond layer and a base material as the tool material, and is configured so that the cutting edge portion is formed by negative land treatment. It is possible to suppress the occurrence of chipping at the cutting edge portion during cutting edge processing by grinding. In addition, since the rake face is constructed using the base material, the process for removing the base material can be omitted, making it possible to simplify and shorten the manufacturing process. Crystalline diamond tools can be manufactured.

[Brief explanation of the drawing]

FIG. 1 is a first process diagram showing the manufacturing process of a polycrystalline diamond tool according to the present invention.

FIG. 2 is a second process diagram showing the manufacturing process of the polycrystalline diamond tool of the present invention.

FIG. 3 is a third process diagram showing the manufacturing process of the polycrystalline diamond tool of the present invention.

FIG. 4 is a fourth process diagram showing the manufacturing process of the polycrystalline diamond tool of the present invention.

FIG. 5 is a fifth process diagram showing the manufacturing process of the polycrystalline diamond tool of the present invention.

FIG. 6 is a sixth process diagram showing the manufacturing process of the polycrystalline diamond tool of the present invention.

FIG. 7 is an enlarged perspective view of the cutting edge portion of the indexable tip of the present invention.

FIG. 8 is a partial cross-sectional view of the cutting edge portion of a conventional polycrystalline diamond tool.

[Explanation of symbols]

1 Base material 2 Polycrystalline diamond layer 3 Chip 4 Tool support 5 Brazing part 6 Rake face 7 Relief surface 8　Blade tip part 9 Chipping 10 Negaland 11 Land part 12 Laser

Claims (18)

[Claims] 1. A polycrystalline diamond tool comprising a laminate of a thin plate-like base material and a polycrystalline diamond layer synthesized on the surface of the base material by a low-pressure vapor phase method, wherein the back surface of the base material is the rake surface of the tool, the side surface of the polycrystalline diamond layer is the flank surface of the tool, and a negative land is formed between the rake surface and the flank surface, so that the cutting edge of the tool is attached to the side surface of the polycrystalline diamond layer. A polycrystalline diamond tool characterized by having a part formed therein. 2. The polycrystalline diamond tool according to claim 1, wherein the negative land has an angle of 2° or more and 20° or less with respect to the rake face, and a width of 0.3 mm or more and 3 mm or less. 3. The cutting edge portion formed on the side surface of the polycrystalline diamond layer is located within 20 μm from the boundary between the polycrystalline diamond layer and the base material along the direction perpendicular to the rake face. Claim 1 is formed.
Or the polycrystalline diamond tool described in 2. [Claim 4] The magnitude of chipping at the cutting edge portion is 0.
．． The polycrystalline diamond tool according to any one of claims 1 to 3, which has a diameter of 5 μm or more and 5 μm or less. 5. The thickness of the base material is 0.1 mm or more and 1 m.
The polycrystalline diamond tool according to any one of claims 1 to 4, wherein the polycrystalline diamond tool has a diameter of less than m. 6. The base material is Si, SiC, Si3
Made of any one of N4, Mo, and W,
A polycrystalline diamond tool according to any one of claims 1 to 5. 7. The polycrystalline diamond tool according to claim 1, wherein the crystal grain size of the polycrystalline diamond layer is 0.5 μm or more and 15 μm or less. 8. A tool material comprising a laminate of a thin plate-like base material and a polycrystalline diamond layer synthesized on the surface of the base material by a low-pressure vapor phase method, and a tool support for supporting the tool material. A polycrystalline diamond tool having:
The back surface of the base material is the rake surface of the tool, the growth surface of the polycrystalline diamond layer is the joint surface with the tool support, the side surface of the polycrystalline diamond layer is the flank surface of the tool, and the rake surface and the A polycrystalline diamond tool, characterized in that a cutting edge portion of the tool is formed on the side surface of the polycrystalline diamond layer by forming a negative land between the polycrystalline diamond layer and the flank surface. 9. The polycrystalline diamond tool according to claim 8, wherein the negative land has an angle of 2° or more and 20° or less with respect to the rake face, and a width of 0.3 mm or more and 3 mm or less. 10. The cutting edge portion formed on the side surface of the polycrystalline diamond layer is located at a position within 20 μm from the boundary position between the polycrystalline diamond layer and the base material along the direction perpendicular to the rake face. A polycrystalline diamond tool according to claim 8 or 9, wherein the tool is formed of a polycrystalline diamond tool. 11. The polycrystalline diamond tool according to claim 8, wherein the size of chipping at the cutting edge is 0.5 μm or more and 5 μm or less. 12. The polycrystalline diamond tool according to claim 8, wherein the thickness of the base material is 0.1 mm or more and 1 mm or less. 13. The base material is Si, SiC, Si3
The polycrystalline diamond tool according to any one of claims 8 to 12, comprising any one of N4, Mo, and W. 14. The polycrystalline diamond tool according to claim 8, wherein the crystal grain size of the polycrystalline diamond layer is 0.5 μm or more and 15 μm or less. 15. The polycrystalline diamond tool according to claim 8, wherein the polycrystalline diamond layer has a thickness of 0.05 μm or more and 1 μm or less. 16. A polycrystalline diamond tool according to any one of claims 8 to 15, wherein the tool support is made of either cemented carbide or steel. 17. A method for producing a polycrystalline diamond tool comprising a laminate of a base material and a polycrystalline diamond layer, the step of synthesizing the polycrystalline diamond layer on the surface of the base material by a low-pressure vapor phase method. a step of polishing the base material to a predetermined thickness to form a rake face of the tool; a step of forming a flank face of the tool on the side surface of the polycrystalline diamond layer; and forming a negative land during the manufacturing process. 18. A method for manufacturing a polycrystalline diamond tool formed by bonding a tool material consisting of a laminate of a base material and a polycrystalline diamond layer to a tool support, the method comprising: applying a low pressure on the surface of the base material; A step of synthesizing the polycrystalline diamond layer by a vapor phase method, a step of polishing the base material to a predetermined thickness to form a rake face of the tool, and a growth surface of the polycrystalline diamond layer becomes a bonding surface. a step of joining the tool material to the tool support, a step of forming a flank surface of the tool on the side surface of the polycrystalline diamond layer, and a step of forming a negative land between the rake surface and the flank surface. A method for manufacturing a polycrystalline diamond tool, comprising: