JPS61142004A - Diamond cutting tool - Google Patents

Abstract

PURPOSE:To make it possible to perform ultra precision cutting on the iron system or nickel system metallic material by providing one or more layer of ceramic coating on the cutting edge of blade section made of diamond. CONSTITUTION:A cutting edge 9 is provided to the blade section with a single crystal diamond chip 2 blazed to a cutting tool shank section 1. And the cutting edge 9 is extremely sharply polished together with a rake face 3 and front flank 4. The blade section having a single TiN coating layer 6 of several mum in thickness uniformly ceramic coated on a single crystal diamond 5 makes it possible to perform ultra precision cutting on the iron system or nickel system metallic material having high chemical affinity with diamond.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a diamond cutting tool, and particularly to a diamond tooling tool that has been improved so that it can be applied to ultra-precision cutting of metal materials that have a high chemical affinity with diamond.

[Prior Art] Single-crystal diamond cutting tools have been known as cutting tools for ultra-precision cutting.

However, diamond has an extremely high chemical affinity with metals such as iron and nickel, and for this reason, even when ultra-precision cutting of such metal materials is attempted, extreme cutting tool wear occurs and the diamond is damaged. The actual situation was that the sharp cutting edge was lost, making it impossible to perform any actual cutting operations. For this reason, the application of ultra-precision cutting using a diamond cutting tool to metal materials is limited to soft metals such as copper-based and aluminum-based metals that do not have the above-mentioned chemical affinity.

Apart from such diamond cutting tools, it is also possible to use cutting tools such as cemented carbide or CBN (cubic boron nitride), which are widely used in ordinary cutting, as tools for ultra-precision cutting. Although these materials are chemically stable with the metal materials mentioned above, they are generally powder sintered materials obtained by sintering powder raw materials with a binder, etc., so they have sharp edges suitable for ultra-precision cutting. It was difficult to create a cutting edge without minute irregularities, making it unsuitable as a tool material for ultra-precision cutting.

In addition, recently, chemically stable base materials such as cemented carbide,
In addition, tools have been developed and marketed that have improved wear resistance by coating them with ceramic materials such as highly hard carbides, nitrides, or oxides. Because we use powdered sintered material,
It does not have a sharp cutting edge, making it unsuitable for ultra-precision machining, and there is currently no suitable cutting tool material to replace single-crystal diamond. The situation is such that ultra-precision cutting of metal materials is not possible.

[Problems to be Solved by the Invention] The present invention has been made in view of the above-mentioned points, and the main purpose of the wooden invention is to eliminate the drawbacks of the conventional diamond bit, and to The object of the present invention is to provide a new single-crystal diamond cutting tool that enables ultra-precision cutting of metal materials such as nickel.

[Means for Solving the Problems] A diamond cutting tool of the present invention that achieves the above object includes a shank and a blade portion having a cutting edge, and at least the blade portion is made of single crystal diamond. Additionally, one or more ceramic coating layers are provided on at least the cutting edge of the diamond constituting the blade portion.

[Embodiments of the Invention] The present invention will be described in detail below with reference to the drawings as necessary.

FIG. 1 is a diagram illustrating an embodiment of the diamond cutting tool of the present invention, and is a perspective view of the cutting tool. Furthermore, the first
The figure shows the state before ceramic coating is performed.

As shown in Fig. 1, the diamond cutting tool of this example has a blade part attached to the shank (hereinafter referred to as the cutting tool shank part 1), which is the part that is used for mounting on cutting machines such as lathes, boring machines, and planing machines. The constituting chip, in this example a diamond chip 2 made of single crystal diamond, is attached by known joining means such as brazing.

A cutting edge 9 is provided on the blade portion. When configuring the cutting blade 9, various measures are generally taken to facilitate cutting or increase cutting efficiency, such as providing a rake face or a front flank face, depending on various purposes. However, of course, various such measures are taken in wood inventions as well. Incidentally, in the cutting tool of this example, the cutting edge 9, together with the rake face 3 and front flank face 4, is extremely sharp and has been polished to a roughness of about a few uRmax by a known method such as table polishing. ing.

Such a cutting edge 9 has a processing surface roughness accuracy of 0.01 to 0.
．． I JIJII In order to perform ultra-precision cutting that requires approximately Rmax, it must be extremely sharp and
It is necessary that there be no minute irregularities on the contact surface with the object to be cut. However, in conventional bits using cemented carbide, CBN, etc., these bit materials are powder sintered materials, and microscopically, particles of various intensities are bonded through a matrix, and in some cases, Unlike a single crystal, which is composed of single particles and has a homogeneous internal structure, it has a heterogeneous internal structure that also contains pores. It is unavoidable that minute irregularities occur on the cutting edge. Also.

Even if coating is performed, the unevenness of the base will remain on the coated surface, and it is inevitable that minute unevenness will occur on the cutting edge. However, since wood invention uses a single crystal that does not have the above-mentioned inhomogeneity in wood quality, it is possible to construct a cutting edge without the above-mentioned minute irregularities, making it suitable for ultra-precision cutting. It is possible to implement

The processing means used to construct such a cutting edge is not particularly limited, and a well-known method such as polishing means can be selected as appropriate depending on the required cutting accuracy and the like.

Figure 2 shows a ceramic coating, in this example TiN.
1 is a partial cross-sectional view of the cutting tool of FIG. 1 in a completed state after carrying out a single-layer coating.

As shown in FIG. 2, the cutting tool of this example has a single-layer TiN coating layer 6 formed by sputtering on a single-crystal diamond 5 as a coating base, which is uniformly coated with a film thickness of about several μs. It has a blade with a similar configuration. Of course, by applying such a coating, the sharpness of the cutting edge 10 is not lost, and by providing such a ceramic coating layer, it is possible to improve the sharpness of the cutting edge 10, which was previously difficult due to its high chemical affinity with diamond. Ultra-precision cutting of metal materials such as iron and nickel becomes possible. By the way, in the cutting tool of this example, the surface roughness of the TiN coating layer 6 is as follows: rake face 7, front flank face 8
Both are 2/IQO ~ 3/100 u Rmax,
The cutting edge 10 had sufficient sharpness for ultra-precision cutting. When I tried ultra-precision cutting of Ni material using a lathe using this tool, I noticed that the surface was rough. /100100uR could be obtained.

The cutting tool of the present invention is completed by providing a ceramic coating layer such as the TiN coating layer 6 above on the single crystal diamond 5, but the coating may be performed after the external appearance of the cutting tool is formed as in this example. Of course, it is also possible to coat a diamond tip whose cutting edge including the cutting edge has been finished in advance with desired precision and shape, and then attach this to the shank to complete the cutting tool. Such a coating layer may be a single layer as in the above example, or may be two or more layers as necessary.

In the present invention, it is essential to provide a ceramic coating layer on the cutting edge, but there are no particular limitations on other parts. For example, as in the above example, both the rake face and front flank face with the cutting edge It is also possible to provide a ceramic coating layer, and depending on the type of material to be cut, it may be possible to coat only the immediate face containing the cutting edge, or only the front flank face containing the cutting edge, reducing coating time and coating. It is also possible to reduce the consumption of materials, etc. ') As the single crystal diamond in the present invention, both natural and synthetic diamonds can be used.

In addition to the above-mentioned TiN, materials constituting the ceramic coating layer laminated on the single-crystal diamond include:
Various materials known for this kind of coating technology,
For example, carbides such as TiC, IIC, and SiC, BN,
Nitride such as HfN, TaN, ZrN, Al2O
Examples include those having high hardness, such as oxides such as No. 3 and composite compounds such as carbonitrides such as No. 3 (ON).

One or more of these materials are combined to form a ceramic coating layer on the single-crystal diamond, consisting of one or more layers. The coating thickness is between 0.5 μm and 2 μm, so that the properties of the diamond as the base are not lost and the coating effect is fully demonstrated.
Scales are preferred.

Such a ceramic coating layer can be formed using various methods that are generally widely known in this type of technology, but preferably sputtering and ion methods that can form a homogeneous film are used. Plating method, C
VD method or CVD method with plug.

The present invention has been explained above mainly in terms of ultra-precision cutting, but
It goes without saying that the diamond cutting tool of the present invention can be applied not only to ultra-precision cutting but also to ordinary cutting.

[Effects of the Invention] As explained above, the diamond cutting tool of the present invention, which is a single-crystal diamond coated with a ceramic coating, can cut iron-based metals, which conventionally could not be cut with ultra-precision due to their high chemical affinity with diamond. Ultra-precision cutting of metal materials such as nickel-based materials is now possible.

[Brief explanation of drawings]

1rf4 and 2 are diagrams each illustrating an embodiment of the diamond cutting tool of the present invention, and FIG. 1 is a perspective view of the cutting tool before ceramic coating, and FIG.
The figure is a partial sectional view of the blade portion of the cutting tool shown in FIG. 1 after ceramic coating has been applied. 1--Bite shank part 2-m-Diamond tip 3.7--Rake surface 4.8-11 Front flank surface 5--
- Single crystal diamond 8-m - TiN coating layer 9.10-m - Cutting edge

Claims (3)

[Claims] (1) It includes a shank and a blade portion having a cutting edge,
A diamond cutting tool, characterized in that at least the blade portion is made of single-crystal diamond, and one or more ceramic coating layers are provided on at least the cutting edge of the diamond constituting the blade portion. (2) The diamond cutting tool according to claim 1, wherein the coating layer is formed by a sputtering method, an ion plating method, a CVD method, or a plasma CVD method. (3) A patent in which the blade portion is provided with a rake face and a front flank face sandwiching the cutting edge, and the coating layer is provided on the cutting edge, the rake face, and/or the front flank face. A diamond cutting tool according to claim 1.