JPH0355163A - Grinding material and its manufacture - Google Patents

Abstract

PURPOSE:To raise the polishing and grinding power and the durability by covering the surfaces of abrasive grains with needle-shaped or columnar diamond film and/or diamond type carbon film. CONSTITUTION:A needle-shaped or columnar diamond film and/or a diamond like carbon film are formed over the surfaces of abrasive grains by the plasma gaseous phase deposition method in which 1-10GHz is impressed under the hydrocarbonic and hydrogen atmosphere. Thus the desired grinding material is obtained. This should enhance the polishing and grinding power and the durability of the grinding material.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention is a highly durable and highly abrasive product that is used for polishing metals, wood, ceramics, plastics, etc.
The present invention relates to an abrasive material that does not easily clog and a method for producing the same.

(Prior art) Conventionally, various abrasive grains are applied to the material to be polished, such as those with high hardness such as alumina, carborundum, and zirconia, and those with relatively low hardness such as silica sand and emery. There are abrasive materials such as abrasive cloths fixed to paper surfaces with adhesives, sandpaper, abrasive belts molded for polishing and grinding machines, abrasive discs, and whetstones. The abrasive grains of these abrasive materials are manufactured by crushing natural ores and synthetic castings to produce products with various particle size distributions, but this method has the disadvantage of requiring a huge amount of electricity and a long process. Ta.

Diamond abrasive grains have the highest hardness among abrasive grains, but there are few natural resources for industrial use, and artificial diamonds, which are synthesized under high temperature and pressure, have low productivity and are expensive, making them difficult to use in industry. It has not yet become widely popular.

(Problems to be Solved by the Invention) An object of the present invention is to provide a relatively inexpensive diamond abrasive that has excellent polishing power, is less likely to cause clogging, and has improved the above-mentioned drawbacks.

(Means for Solving the Problems) In order to solve the above problems, the inventors of the present invention have conducted intensive studies on the material of abrasive grains and the method of surface treatment thereof, and have arrived at the present invention. 1. 2. An abrasive material whose abrasive grain surface is coated with an acicular and/or columnar diamond film and/or a diamond-like carbon film; 1 to 10 on the abrasive grain surface in a hydrocarbon and hydrogen atmosphere.
2. The method of manufacturing an abrasive material according to claim 1, wherein the acicular and/or columnar diamond film and/or diamond-like carbon film is formed by a plasma vapor deposition method applying GHz.

The present invention will be explained in detail below.

First, examples of abrasive grains include those with high hardness similar to diamond, such as alumina, carborundum, and zirconia, and those with relatively low hardness, such as silica sand and emery. A surface-treated diamond film and/or diamond-like carbon film that adheres well, does not peel off easily, and is inexpensive is preferable, such as alumina silicon carbide. The particle size of the abrasive grains may be selected appropriately taking into account the material, hardness, finish roughness, and other physical properties of the target material to be polished, but in general, #
120~#1500. It is also important that the shape is an irregular polyhedron; particles with smooth and wide surfaces or with few acute angles lack polishing power.

Next, the surface of the abrasive grains is coated with a diamond film and/or a diamond-like carbon film by plasma vapor deposition. The purpose of this is to use the minimum necessary amount of diamond, which has the highest hardness among materials, to achieve the maximum polishing effect. Diamond film and/or diamond film deposited on the surface by plasma vapor deposition method.
Alternatively, the diamond-like carbon has needle-like and/or columnar crystals, and the thickness thereof is preferably in the range of 10 to 1,000 μm, preferably 20 to 500 μm. 10μ
If it is less than 1.0 m, it will be too thin and unreliable.
If it exceeds 00 μm, the frictional resistance during polishing will increase, clogging will occur easily, and the polishing power will decrease rapidly. This plasma vapor deposition method can be performed using a known technique, using a gas mixture consisting of hydrocarbon and hydrogen or, if necessary, an inert gas, to form a diamond film and/or diamond-like carbon film from hydrocarbon to diamond film on the surface. It is carried out by a method of precipitating. The volume ratio of hydrocarbon (A) and hydrogen gas (B) is A/B=500 to 0. Can be used in a wide range of 001. The volume ratio of hydrogen gas (B), inert gas (C) and hydrocarbon (A) to be used is A/B+C=
5'OO~0.001, the substitution rate of C for B is 5
It is preferably 0% or less. Examples of plasma vapor deposition methods in this case include high frequency, direct current, microwave, plasma methods using metal wire heating coils, and ion beam evaporation methods.
It is preferable to use microwave high frequency power of 10 GHz. Reliable thin films cannot be obtained below I GHz.

Examples of the hydrocarbon used here include methane, ethane, propane, and ethylene, with methane being preferred.

In carrying out this method, first, abrasive grains are placed in a single layer in a reactor so that the particles do not overlap, and a mixed gas of hydrocarbon and hydrogen or, if necessary, an inert gas is introduced into the reactor. The pressure inside the chamber is adjusted to a range of 10 (1 to 220 Pascals) in order to maintain a stable plasma, and then microwave high frequency power is applied to this to generate plasma in the system, and the parts are heated. temperature is 500
Adjust the temperature to ~1300°C. Part temperature is 500
If the temperature is below 1300°C, hydrogen may be mixed into the precipitated diamond film, and if the temperature exceeds 1300°C, the deposited diamond will undergo reverse transition to graphite.
The temperature is preferably within the range of 00°C. As a result, the hydrocarbons are thermally decomposed by contact with the plasma flame, and a diamond film containing diamond or graphite and/or a diamond-like carbon film is formed into a uniform plate shape and deposited to a desired thickness. .

Next, specific aspects of the present invention will be explained with reference to Examples, but the present invention is not limited thereto.

(Example) Alumina abrasive grains having polyhedrons sized to #120 were placed on an abrasive support table of a reactor having a waveguide port and a pair of plungers inside, and a gaseous mixture was flowed onto the abrasive They were laid out flat in the direction. Next, after exhausting the pressure inside this reactor to about 5 Pascal, methane (concentration concentration 4
A mixed gas of hydrogen (% by volume) and hydrogen was introduced, the pressure inside the reactor was adjusted to 150 Pascals under gas flow, and under this atmosphere microwaves (2.45 G) were transmitted from a magnetron.
Hz) is guided through an isolator, a power motor, and a three-stap tuner to a quartz reaction tube using a waveguide to generate a plasma discharge around the abrasive grains, bringing the abrasive grains to a predetermined temperature of 930°C. microwave power to 30
When the power was adjusted to 0W, a 100 μm columnar diamond crystal film was formed on the abrasive grains. A belt-shaped polishing cloth was made from the abrasive grains thus produced and phenolic resin, and a grinding test was conducted. The grinding conditions were a feed rate of 4 m/min. In the case of wet down cutting, the effective depth of cut was 0.1 mm when the number of grinding was 500. Under the same conditions, in the case of alumina abrasive grains, AA80# is 0. 04mm, it was found that it was clearly effective compared to this.

(Effects of the Invention) The present invention provides excellent polishing, grinding power, and durability by coating the surface of the abrasive grain with a diamond film and/or a diamond-like carbon film by plasma vapor deposition method.
This abrasive material is difficult to clog and has extremely high industrial value.

Claims (2)

[Claims] 1. An abrasive material in which the surface of abrasive grains is coated with an acicular and/or columnar diamond film and/or a diamond-like carbon film. 2. 1 to 10 on the abrasive grain surface in a hydrocarbon and hydrogen atmosphere.
2. The method of manufacturing an abrasive material according to claim 1, wherein the acicular and/or columnar diamond film and/or diamond-like carbon film is formed by plasma vapor deposition method applying GHz.