KR20020069625A - CVD (chemical vapor deposition) diamond pencil and cutter - Google Patents

Abstract

PURPOSE: Diamond pencils and cutters manufactured of CVD diamond are provided in which various shaped diamond pencils and cutters having uniformed physical properties are inexpensively mass-produced by manufacturing new type diamond pencils and cutters using chemical vapor deposition diamond. CONSTITUTION: In fabricating diamond pencils used for engraving a character on a substrate such as glass, metal, ceramics and plastics or diamond cutters used for cutting the substrate materials, the diamond pencils and cutters are characterized in that they are manufactured of CVD diamond in chemical vapor deposition process, wherein a chemical vapor deposition diamond covering layer is uniformly covered to a thickness of 1 micron or more and less than 500 microns on parts of the diamond pencils and cutters which are a shank made of hard metal, ceramics or cermet.

Description

{CVD (chemical vapor deposition) diamond pencil and cutter}

The present invention is a diamond pencil or diamond cutter used for precision processing and cutting of metals such as glass and silicon wafers, porcelain and plastics, and for writing or light on surfaces. It relates to the manufacture of).

Diamond is one of the hardest existing materials, electrically insulating and chemically stable, and is widely used industrially due to many other excellent physical properties.

Diamond pencils and cutters utilize the excellent hardness (hardness) of these diamonds and, as mentioned above, are used to engrave, mark, or cut to desired shapes on various kinds of materials. In other words, by using the diamond of the highest hardness to create a scratch on a material of a weaker hardness, it is possible to engrave the text and cut through it. At present, the configuration diagram of the diamond pencil and the cutter of the simplest type used in the industry is shown in FIG. 1 is a diamond particle that is responsible for engraving or cutting of letters, ② and ④ are shanks to which diamond particles are welded, and ③ are handle portions for the convenience of the operator. The shank (② or ④) part is responsible for the stress load on the diamond particles during engraving or cutting of the material, and the handle part (③) is an additional device, for example, a power transmission device or an ultrasonic wave, if necessary. It is connected to the generator and used.

In Figure 1 is composed of ①, ②, and ③, the diamond pencil is made, if composed of ①, ④, and ③, the diamond cutter is made. A diamond cutter is the same as a diamond pencil except that the shape of the base (shank) to which the diamond is welded is made to apply the force required for cutting. 2 is a view of a completed diamond pencil. 1 of Figure 1 is natural and artificial diamond can be seen that the process of processing the cone by welding to the shank to facilitate scratching and engraving of the letters.

The most important factor that determines the performance of these diamond pencils (hereinafter also referred to as diamond cutters) is the physical properties of the diamond particles themselves. In this regard, the problems of the existing diamond pencil are as follows. First of all, the diamond particles currently used are natural or artificial diamonds. In the case of natural diamonds, tens of tonnes of soil are dug up to get one carat of diamonds, and in the case of artificial diamonds, it is very necessary that the equipment maintain high temperature and 2-50,000 atmospheres for synthesis. There is a problem of high price. In addition, natural and artificial diamond is composed of a single crystal (single crystal) has a big difference in physical properties depending on the crystal direction of each diamond particle. The difference in physical properties depending on the crystal direction of the diamond makes it impossible to manufacture diamond pencils of uniform physical properties. In practice, it is impossible to make pencils by selecting the respective crystal directions within a few mm of the size of the diamond particles used, and therefore, the lifespan varies depending on the diamond pencil, and diamond breakage occurs easily depending on the given conditions. In other words, it is impossible to produce a pencil or cutter with a uniform lifetime. Another problem is that post machining is essential after each diamond is welded to the shank. As can be seen in Figure 2, in general, the diamond must be processed into a conical shape in order to cut effectively by engraving or scratching the material. By the way, the processing of diamond is very difficult work, and therefore, about half of the diamond pencil manufacturing cost is required for processing. The individual work of welding each diamond to each shank and the cumbersome process of processing each one again are essential, and the shape and shape of the pencil made according to the size and shape of the diamond gemstone are also limited.

In the present invention, the problem that the diamond itself, which is a raw material of existing natural and artificial diamond pencils and cutters, is expensive, extremely difficult to finish diamonds is essential, difficulty in obtaining uniformity of physical properties, and lighting such as welding are required. The aim is to produce diamond pencils and cutters that are all made in an improved new way. In order to achieve this purpose, CVD diamond manufactured by chemical vapor deposition (CVD) is used, and it has various shapes and sizes, and manufactured products have the same physical properties, and welding or post-processing processes It is directed to the manufacture of diamond pencils and cutters that can be produced in high volume without the need.

1 is a conventional diamond made of natural and artificial diamond

Pencil Diagram

Figure 2 is a finished product of the existing diamond pencil of Figure 1

3 is a diamond pencil made of a chemical vapor deposition diamond

Configuration

Figure 4 is a base material (shank) is formed with a chemical vapor deposition diamond coating layer

Cross section

<Description of the symbols for the main parts of the drawings>

①: natural and artificial diamond particles

②: Base material on which diamond is welded (shank)

③: handle

④: Example of base material (shank) in diamond cutter manufacturing

⑤: The area of the base material (shank) coated with the chemical vapor deposition diamond film

⑥: Chemical vapor deposition diamond coating layer coated on base material (shank)

⑦: Base material processed into cone shape (shank)

In the present invention, to achieve the above object is characterized by using a diamond produced by the chemical vapor deposition method.

Advantages of using vapor-deposited diamonds over natural and artificial diamonds include: First of all, the vapor-deposited diamond uses hydrogen and methane gas as its main raw materials, unlike artificial diamond obtained from powdered diamond particles by applying pressure of 2-40,000 at high temperature using conventional solid carbon. A diamond synthesized by addition, which can be obtained as a diamond coating layer of uniform thickness on a base material (shank) maintained at a temperature of 800-1200 ° C. Therefore, the diamond coating layer of predetermined thickness depending on the shape of a base material (shank) can be obtained. That is, by changing the shape of the base material, it is possible to form a diamond coating layer according to the shape, and to use it as a diamond raw material of diamond pencils or cutters in place of existing natural and artificial diamonds. Therefore, it is possible to manufacture diamond pencils and curlers of various shapes and sizes.

On the other hand, since natural and artificial diamonds are single crystals, CVD diamonds are diamonds having a size of several nm to several μm, unlike those having different physical properties (abrasion resistance) depending on the crystal direction. Polycrystalline, made of particles, with uniform physical properties in all directions. Therefore, diamonds synthesized under the same conditions have the same physical properties in all directions, and diamond pencils and cutters made under the same conditions have the same physical properties.

Secondly, it is possible to significantly reduce the unit cost of diamond pencil production by eliminating the need for an individual diamond post-processing process, which is essential for the production of existing natural and artificial diamond pencils. Generally, cemented carbide, cermet, ceramic, etc. are used as the base material (synthesis), and the adhesion is excellent. The shank of desired size and shape (7 in Fig. 3) is made to form a diamond coating layer according to the shape. Form it and attach it to the handle (3 in Figure 1) to complete the production of the diamond pencil. That is, the desired diamond shape can be obtained by processing the base material (shank), which is much easier to process, not the processing of artificial and natural diamond, and can be applied to the diamond pencil as it is.

Third, as mentioned above, since the diamond coating layer is directly formed on the shank (base material) of FIG. 1, the welding process between natural and artificial diamonds and the shank is unnecessary. That is, the diamond shank directly plays the role of diamond, simplifying the manufacturing process. In addition, there is no need for a welding process, so that high temperature oxidizing atmosphere exposure during welding does not cause problems of diamond properties deterioration and precise dimensional adjustment.

Fourthly, it is possible to form a diamond coating layer on a large scale at the same time the processed shank, thereby enabling inexpensive mass production.

3 is a block diagram of a diamond pencil produced according to the present invention. The diamond coating layer is formed by vapor phase chemical vapor deposition on the shank (⑦ of FIG. 3) appropriately pre-processed for the required purpose (spinning of ⑤ in FIG. 3 and ⑥ in FIG. 4), and the shank is fitted to a handle for ease of operation. Surface production is complete.

Example

A cylindrical cemented carbide material (shank) of 2 mm in diameter and 7 mm in length is machined into a cone to maintain a 45 ° angle at one end. The processed cemented carbide material is heat treated to remove metal components in order to enhance the bonding force in forming the diamond coating layer. The treated shank is placed in a high temperature filament vapor deposition apparatus to flow a mixed gas of 2% methane and 98% hydrogen in a 40 torr atmosphere, and the diamond coating layer is coated for 10 hours while maintaining the shank temperature at 850 ° C. Due to this synthesis, a uniform diamond coating layer having a thickness of 20 μm is formed on the cemented shank while maintaining a conical shank shape. The shank having the diamond coating layer formed is inserted into a handle made of an iron alloy having a hole having a diameter of 2 mm, thereby applying a compressive stress to prevent the diamond pencil from being pulled out. When the diamond pencil was subjected to a 15kg load to scratch the glass plate, no fracture was observed in the diamond pencil and the glass plate could be cut.

According to the present invention, there are various problems of diamond pencils and cutters made of conventional natural and artificial diamonds, that is, very expensive, non-uniform physical properties, and improved vapor deposition chemical diamond, which improves the need for a welding process and a diamond post-processing process. It is possible to manufacture new types of diamond pencils and cutters, which makes it possible to produce diamond pencils and cutters with uniform properties and various shapes at a very low cost, thereby increasing productivity and performance of existing diamond pencils and cutters. It is possible to strengthen the competitiveness with developed countries in this field. In addition, it is possible to produce diamond pencils and cutters of various shapes and sizes is expected to be applied in a wide range of applications.

Claims (2)

CVD diamond produced by chemical vapor deposition in the manufacture of diamond pencils and diamond cutters used for engraving, marking, and cutting of glass, metal, magnetic (ceramic) and plastics, etc. Diamond pencil and cutter The method of claim 1, wherein a portion of the diamond pencil and cutter is cemented carbide, A diamond pencil and a cutter, characterized by uniformly coating a vapor-coated chemical vapor deposition diamond coating layer having a thickness of 1 m or more and less than 500 m based on Mic and Cermet.