JPS6333571A - Formation of film on spherical body - Google Patents

Abstract

PURPOSE:To form a film nearly uniformly on the whole surface of each spherical body in simple stages by supporting the spherical body at plural points and carrying out chemical vapor deposition. CONSTITUTION:Each steel sphere 6 such as a bearing is supported on a fixing table 8 by support rods 9 at three or more points. Each of the support rods 9 is a wire made of a heat resistant material and has an acute tip. The table 8 is set on a shelf 5 in a reactor (not shown) and a film 10 is formed on the surface of the steel sphere 6 by chemical vapor deposition. Thus, the homogeneous film 10 of a uniform thickness can be formed on the whole surface of the steel sphere 6 except the support points of the support rods 9 in simplified stages.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] This invention relates to a method for uniformly applying a coating to the surface of a steel ball such as a bearing by chemical vapor deposition.

[Conventional technology]

FIG. 3 is a sectional view showing the structure of a boat-type chemical vapor deposition apparatus. In the figure, (1) is a reaction vessel, (2) is a heating furnace,
(3) is a reaction gas inlet pipe, (4) is a reaction gas ejection nozzle, (5) is a shelf, (6) is a steel ball which is a workpiece, and (7) is a gas exhaust pipe.

Further, Fig. 4 is a cross-sectional view showing the installation state of steel balls during chemical vapor deposition, and Fig. 5 shows the state of film formation when chemical vapor deposition is performed with the installation state of the steel balls shown in Fig. 4. FIG. In the figure, 00) indicates a coating.

Next, I will explain the operation in detail. The reaction gas introduced from the outside through the reaction gas introduction pipe (3) is passed through the reaction gas injection nozzle (
4), the reaction vessel (1) is filled with a reaction gas atmosphere near the surface of the steel ball (6) placed on the shelf (5).

On the other hand, the reaction container (1) is heated by the heating furnace (2) on the outer periphery, and the inside of the reaction container (1) is also brought to a predetermined heating temperature state.

In such a state, the reaction gas performs a thermochemical reaction on the surface of the steel ball (6), which has already been heated, and deposits a solid on the surface of the steel ball (6). The gas after the reaction or a portion of the unreacted gas is discharged to the outside from the gas exhaust pipe (7).

For example, when forming a Tie film, TlC14 and C1 (4 gases are used as reaction gases, Tic l J+
The reaction of CI+4→TiC+-411Cj' was heated at a temperature of 1
Perform at 050°C.

[One point while the invention is trying to solve] Generally, the steel ball (6), which is a workpiece, is placed in a reaction vessel (1),
As shown in Fig. 5, the steel ball (6) is placed directly on the shelf (5), but the coating is deposited on the surface of the steel ball (6) at the contact area with the shelf (5) and its surroundings, as shown in Fig. 5. However, there is a problem that the film α is not formed or the film thickness is thinner than other parts.

The solution to this problem is to carry out chemical vapor deposition twice, and in the second process, place the bottom in the first process to the top, and then polish the surface, which is complicated and unreliable. Ta.

On the other hand, in the physical vapor deposition method,
Uniform coating is achieved by the method shown in Vol. 6, No. 6 (1980) PI3).

In Fig. 6, αυ is a vacuum chamber, (support) is a rotating barrel that is installed in the vacuum tank αυ and gives rotational motion to the steel ball (6), and αJ is a motor that rotates the rotating barrel αυ via a gear circle. , (2) indicates the shutter, and the symbol indicates the evaporation source.

The evaporation light source ffG) is heated to a temperature above its melting point by an electron beam or resistance heating, and the shutter is opened after a predetermined evaporation condition is reached.

On the other hand, the surface of the steel ball (6) housed in the rotating barrel (2) rotated by the drive from the motor α3) has no evaporation source.
01, the position is always changed into a round shape, and a substantially uniform coating layer can be obtained after a predetermined period of time.

However, this method cannot be applied to chemical vapor deposition in which the ambient temperature is above 1000''cAt due to mechanical limitations, and cannot be applied to plasma chemical vapor deposition because it disturbs the electric field of the plasma.

This invention was made to solve the above-mentioned problems, and its purpose is to establish a method in which a coating can be applied almost uniformly over the entire surface of a steel ball and post-processing can be omitted.

[Means for solving problems]

This invention applies to chemical vapor deposition of spherical objects such as bearings.
A method for forming a film of a spherical object in which the spherical object is supported at three or more points, and the support for the spherical object is a wire made of a heat-resistant material, and the tip thereof is a pointed angle. It is something.

[Effect]

In the method of forming a coating on a steel ball according to the present invention, a steel ball is supported by three steel wires, and the contact portion with the steel ball is made particularly thin to form a uniform coating over the entire surface of the steel ball.

With the three-point support in this invention, only the three points in contact are not coated, and the other surfaces are in the same reaction gas atmosphere, so a film of uniform thickness can be formed, and the number of processing times and processing steps can be simplified. This is something that can be improved.

Next, an embodiment of the present invention will be described.

〔Example〕

FIG. 1 is an explanatory diagram of the method of the present invention.

In FIG. 1, (8) is a fixing base, and (9) is a support line. Moreover, FIG. 2 is an enlarged cross-sectional view after the coating is formed.

As shown in the figure, three support wires (9) made of a heat-resistant material that does not deform at chemical vapor deposition temperatures are joined to a fixing base (8) in a positional relationship that forms the vertices of an equilateral triangle.

The tip of the support wire (9) tapers as shown in FIG. 2, and the distance between the three points at the tip is maintained at about the radius of the steel ball (6). Steel balls (6) are placed on these three points, and a fixing stand (8) is placed on the shelf (5) shown in FIG. 3. A chemical vapor deposition process is then performed.

After the treatment, as shown in Figure 2, no film is formed at only the three extremely small points that contact the tip of the support wire (9), and the reaction gas circulates around the other parts uniformly, resulting in a uniform film thickness. A film is formed.

In addition, although the said Example demonstrated the thing with three support lines, three or more may be sufficient. Further, the support line may have any shape as long as it supports the steel ball at three or more points.

Further, the workpiece can be made of any material other than steel as long as it is spherical, and the same effects as in the above embodiment can be achieved.

Further, in the above embodiment, a film formation method using chemical vapor deposition was described, but a similar film formation method would exhibit similar effects.

[Effect of investigation]

As described above, according to the present invention, since the steel ball is supported and fixed at three or more points, a homogeneous film with a uniform thickness can be formed over almost the entire surface, and the number of processing times and processing steps can be simplified. This has the effect of making it possible to achieve better results.

[Brief explanation of drawings]

FIG. 1 is a side sectional view showing a vapor deposition jig according to an embodiment of the invention, FIG. 2 is a side sectional view showing the state after film formation according to the invention, and FIG. 3 is a side sectional view showing the configuration of a chemical vapor deposition apparatus. Figure 4 is a side sectional view showing the conventional vapor deposition method, Figure 5 is a side sectional view showing the conventional vapor deposition method.
The figure is a side sectional view showing a conventional vapor deposition method, and FIG. 6 is a side sectional view showing a conventional physical vapor deposition method. (1) is a reaction vessel, (5) is a shelf, (6) is a steel ball, (8)
is the fixed base, and (9) is the support line. Note that the same reference numerals in the figures indicate the same or corresponding parts. Agent Patent Attorney Masuo Oiwa Figure 1, 9: Supporter, Figure 2, Figure 3, Figure 4, Figure 5, 1o: 15,000 yen.

Claims (2)

[Claims] (1) A method for forming a film of a spherical object, which comprises supporting the spherical object at three or more points in chemical vapor deposition of the spherical object. (2) The method of forming a film for a spherical object according to claim 1, wherein the support for the spherical object is a wire made of a heat-resistant material, and the tip thereof is pointed.