JPS5970767A - Method and device for coating by glow discharge - Google Patents

Abstract

PURPOSE:To perform uniform surface coating or hardening of the work, by disposing the conductive work and an auxiliary cathode in a vacuum chamber conrg. the gaseous material of a metallic compd. and reactive gas under adequate partial pressure and generating glow discharge. CONSTITUTION:The conductive work 113 of steel or the like connecting to a cathode terminal 117 is disposed and a auxiliary electrode 112 is disposed in proximity to the position where the mutual effect of the hollow cathode discharge effect and glow discharge is generated in the work, in a reaction furnace 114. The gaseous material of a metallic compd. obtd. by blowing a carrier gas such as H2 to a soln. 122 of a metallic compd. such as TiCl4 and reactive gas such as CH4 are introduced through a gas introducing port 119, and the inside of the furnace is reduced in pressure to <=10 Torr degree of vacuum by an evacuator 120 provided with a trapper 121. A power source 115 is connected to an anode terminal 116 and the terminal 117 to generate glow discharge, thereby coating the resulted product of reaction such as TiC on the surface of the work 113. The partial pressure of the gaseous material in the above-mentioned method is maintained under the pressure smaller than the partial pressure of the reactive gas.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a method and apparatus for coating a conductive article by glow emission, and particularly to a conductive article connected to a cathode and a coated article in the vicinity of the article. The present invention relates to a method and apparatus for generating a glow discharge between an auxiliary cathode and an anode arranged as a auxiliary cathode to coat the surface of the article with a reactant.

[Prior art]

Until now, CVD and PVD methods have been used as coating methods for conductive articles, and these methods have been used to coat Tic, Tic, and Tic.
iN coatings have been performed. The CVD method uses an electric furnace or high-frequency heating, and a catalytic reaction between the surface of the workpiece and the gas phase on the workpiece heated to around 1000C, such as T
rct, C, and Hs to coat TiC.

The reaction product precipitation process in the CVD method is a solid crystal growth process from the gas phase. becomes the driving force for film growth. Therefore, according to the CVD method, the reaction gas concentration at the interface is generally low because the reaction gas is diffused to the reaction interface by the gas diffusion.

TiC coating by CVD method has a temperature of 2~1000C.
A film of about 5 to 10 μm can be formed only after 3 hours of treatment, and the film formation rate is slow despite the high temperature treatment. In addition, in order to form a film with stable characteristics, fine adjustments are required to control the gas mixture ratio, flow rate, etc.
The coating process becomes complicated. Furthermore, since a high temperature of about 1000 C is required, problems such as embrittlement due to coarsening of crystal grains may occur in steel parts, which are the most commonly used products to be processed, and complicated processes are required to prevent such problems. Such drawbacks also occur in the PVD method. The PVD method has the possibility of coating at low temperatures, but in that case there are disadvantages such as a decrease in adhesion to the object to be treated and a decrease in the rate of generation of the object.

Coating of TiC by glow discharge has also been disclosed [e.g. F. J. Hazlewood and P.
C.

Iordanis: “Abrasion-re, 5is
L3nt, titanium-carbide-1)
2sed coatings formed by gl
ow-discharge-assisted vop
or position”.

pagerl 2, pager29-37, A
dLlances 1nSurface Coat i
ng'['technology
onalConference of the Wel
ding ENG n5 posture and the In5
Titute of Mechanical Engineering
neers.

London, Feb, i 3-15 ('78)
). This coating method is an ion nitriding method using glow discharge.T'icA, f: is used as the gas source, and T is heated in a container with a reduced pressure of at least 10-1'l'o r.
ict, C, l-12, and Ar as a carrier gas.
Coat the TiC using +5% I(,).

In this way, since the object to be processed is heated by glow discharge energy, no external heat source is required. That is, since the surface generating the glow becomes the heat source, the temperature of the object to be processed changes depending on the ratio of the surface to the volume. In other words, if the workpiece is of the same shape and has a relatively simple shape, the temperature will be almost uniform throughout and a uniform coating will be possible, but if the workpiece has a complex shape, especially parts with different areas relative to volume, even if the workpiece is the same, the temperature will be uniform. This causes a difference in ion bombardment energy and ionization density, resulting in a large temperature difference, and the concentration and depth of the diffused atoms vary greatly, causing variations in the film formation rate, making it impossible to form a uniform coating. In particular, in the case of products with uneven surfaces, the glow concentrates on the convex portions where electrons are easily emitted, so that coating is more likely to be formed in these portions, and the concave portions may be hardly coated. This phenomenon is caused by glow radiation.
It varies greatly depending on the discharge voltage at the time. If an attempt is made to heat the battery to 600C or higher by glow discharge, the discharge voltage will rise rapidly. The higher this discharge voltage, the more
The directionality of electron emission becomes cylindrical, and the glow becomes concentrated in positions where it is easy for the electrons to emit.

The ion nitriding coating temperature currently used for millet treatment is approximately 600C, and at this temperature there is little temperature difference due to ion bombardment energy and ionization density. It is difficult to coat the required areas uniformly.

To solve this problem, it has been proposed, for example, to perform ion nitriding in a conventional vacuum heat treatment furnace, or to perform ion nitriding while applying high-frequency heating from the outside. However, in the former case, the object to be processed is heated using a heater such as carbon fiber, which requires a high output heating power source and requires less heating by ions, compared to conventional processing using only ions. As a result, the ion bombardment energy on the processed product is reduced, and the ion distribution ratio on the surface is also reduced. Therefore, the structure and control of the device become complicated, the overall energy consumption is large, and the concentration of atoms involved in the cleaning action of ions, the formation of a film on the surface, or the hardening, etc., is also reduced. In the latter case, when many parts are inserted into the furnace to be heated by induced current caused by high frequency, the temperature at which the individual parts are heated differs depending on the distance from the high frequency coil, and as in the former case, the power supply, II] 'J control becomes complicated. Further, a lot of energy is required for the coating process, and the cleaning effect of ions and the control of the ion concentration on the surface are not sufficient.

On the other hand, depending on the use of the article to be treated, it may be necessary to perform treatments with different functions on different locations within the same article, rather than applying a surface treatment with the same function to the entire surface. In the case of the above-mentioned ion nitriding coating, such treatment cannot be performed continuously in one process in the same furnace;
It was done in multiple steps.

Japanese Patent Application Laid-Open No. 47-1999 is a method for forming partially different hardened layers (for example, hardness, roughness, and hardened layer depth) using the ion nitriding method.
6956 Garuru. In this processing method, an anode ft1l of a DC' power supply is placed between the workpiece (cathode) and the wall of the vacuum container (anode).
By installing an additional metal electrode connected to j through a voltage divider, and changing the potential of this additional electrode, the ion bombardment energy on the workpiece is partially changed to form a partially different treatment layer. ing. According to this method of ion nitriding, the additional metal anode is provided in the vicinity of the workpiece that requires different hardened layers in different parts of the workpiece. In addition, during processing, by changing the potential of the additional metal electrode using an external circuit and changing the ion bombardment energy on the surface of the workpiece in the vicinity, the amount of nitrogen diffusion is controlled, and partially different nitrided layers are formed. It is being formed.

However, in this method, it is difficult to control the ion bombardment energy as a practical matter, and the amount of nitrogen diffusion is significantly influenced by temperature as well as the ion bombardment energy. Therefore, it is extremely difficult to control the hardened layer using this method.

In order to solve this problem, the present inventors placed an auxiliary electrode close to the conductive object to be processed, and generated a glow discharge that interacted between the object to be processed and the auxiliary electrode. We have developed a method for surface treatment in a short time by reducing the discharge voltage of glow discharge on the treated surface of the treated product.

This prior art provides the following surface treatment.

In a method of surface treatment by generating glow discharge between an anode and a cathode in a container under reduced pressure, an auxiliary electrode having a conductive surface placed opposite to the anode and connected to the cathode is used to treat the workpiece. The auxiliary electrode is placed close to the part where it is needed, and the large distance b' between the surface to be processed and the auxiliary electrode is set so as to cause mutual interference between the glow discharges to the extent that the temperature of the required surface part of the part to be processed becomes high. This is a heat treatment method characterized by selecting and arranging the heat treatment in the necessary parts to enhance the heat treatment effect.

The present inventors have carried out CV as a series of research on such surface treatment methods.
The present invention was achieved after intensive study on application to method D.

[Purpose of the invention]

An object of the present invention is to provide a method and an apparatus for uniformly surface-coating the entire conductive article or a target part thereof by glow discharge or surface-curing and surface-coating at low voltage. .

[Summary of the invention]

The present invention combines a gaseous substance of a metal compound and a gaseous substance (reactive gas) that reacts with the metal compound to form a reactant with a conductive workpiece connected to a cathode at a vacuum level of 10 Torr or less. A method of generating a glow discharge between an anode and an auxiliary cathode disposed close to a position where glow discharge interaction occurs on the article to be treated, and coating the surface of the article mentioned above with a reactant. The present invention provides a method and apparatus for coating a conductive article by glow discharge, wherein the partial pressure of the gaseous substance is less than that of the reactive gas.

That is, in the present invention, the gaseous substance of the fluorescent substance reacts with the metal compound to cause a reaction q/! All the four-electrode to be processed parts connected to the cathode are placed in a reduced pressure atmosphere containing a gaseous substance (this gaseous substance may be referred to as a reactive gas hereinafter). At the same time, an auxiliary cathode is provided around the conductive article, and the auxiliary cathode is placed close to the conductive article to the extent that a hollow discharge effect is produced between the auxiliary cathode and the gold-conducting film treated area. By performing several treatments, the reactants of the two or more gaseous substances may be formed as a film on the conductive product.

Note that the hollow discharge effect is a phenomenon in which mutual interference is caused between negative glow generated between the auxiliary electrode and the object to be processed, and the current density is increased during this period. In this part, the ionization density of the gas is also increased, and the surface reaction of target active atoms to the surface of the object to be treated becomes active.

That is, by arranging the auxiliary cathode so as to substantially surround the coating portion of the conductive article, the hollow discharge treatment can be effectively performed. Here, "substantially surrounding" means that the auxiliary cathode almost completely surrounds the coating section, or that the coating section and the auxiliary cathode are relatively moved or rotated to produce the same effect as surrounding it. say.

The glow ridge growth process can also be effectively performed by providing a plurality of auxiliary cathodes and arranging them so as to produce a hollow discharge effect between the auxiliary cathodes or between the conductive objects to be treated inside the auxiliary cathodes.

This auxiliary cathode causes a glow discharge interaction with the workpiece, which causes a gaseous substance of the metal compound to react with the gaseous substance (reactive gas) to form a reactant.
This auxiliary cathode is used as a glow-emitting device.
The turtle's auxiliary energy supply is reduced, and the reactants are supplied from the atmospheric gas. In this case, the gaseous substance of the metal compound is supplied under reduced pressure, for example at a vacuum level of 10 Torr or less. In other words, the partial pressure of the gaseous substance of the metal compound is extremely low, in other words, a very small amount is supplied.
It is necessary to pass this very small amount of gas through the gap between the auxiliary electrode and the workpiece to uniformly distribute the new gaseous substance on the surface of the workpiece. It is necessary to immediately adhere to the narrow surface of the product to be processed without stagnation.

As a result of intensive research to solve these problems, the inventors of the present invention discovered the following.

When the supply amount of the gaseous substance of the metal compound decreases, the reaction material coating formation rate slows down, and as it increases, this formation rate increases, but the resulting coating becomes porous, brittle, and easily peeled off from the processed item. .

For example, using TiCl2 as a gaseous substance of a metal compound dispersed in H7 as a carrier gas and CH4 as a gaseous substance (reactive gas) that reacts with the gaseous substance of this metal compound to form a reactant, 'rict , the partial pressure of C
When the partial pressure of H4 is also increased, fine reactant particles adhere to the surface of the article to be treated in a deposited state, and after 20 to 30 minutes, they become film-like and peel off from the surface of the article to be treated. According to the microscopic observation of the cross section of the coating on this workpiece, almost no TiC was formed, and the partial pressure of TiCl2 should be lower than the partial pressure of CI (4, preferably 0.5 or less). It turned out to be desirable.

Further, the gaseous substance of the metal compound dispersed in the carrier gas is supplied from one side of the coating processing apparatus while being exhausted from the other side. In particular, a gaseous substance of a metal compound dispersed in a carrier gas is supplied to the gap between the auxiliary cathode and the object to be processed, or at least to the surface of the object to be processed, at an equivalent ratio of 1.0 or less to the reactive gas. This metal compound gaseous substance reacts with the glow discharge caused between the auxiliary cathode and the Ju1 product, and the reactant is deposited on the surface of the product to be treated, and the glow discharge occurs depending on the rate of the reaction. Reactive species in the reactor are reduced. Therefore, if the structure is such that the reactive gas stagnates, the reactive gas adjusted to the appropriate amount ratio for the coating treatment will not be uniformly supplied, and the article to be treated will not be coated. Therefore, in order to distribute the reactive gas uniformly and obtain a uniform coating, it is necessary for the reactive gas to move relatively between its supply direction and the coating surface of the workpiece during the coating period. understood. For this purpose, the article to be treated, the reactive gas supply side, or both are moved. For example, the workpiece may be rotated or a rotary gas distributor may be used to supply the reactive gas.

Gaseous substances of metal compounds (including metalloids) used in the present invention include 'l'i, Cr, l'Ji, and Si.

These are halides such as At, Zr, B, Hf, V, W, or Ta, and the gaseous substances that react with the gaseous substance of this metal compound to produce a reactant include CH4, N,
7, borane, etc., and an inert gas, especially Ht and Ar, is used as the carrier gas. The reaction coatings that result in this case are nitrides, carbides, and borides of various metal elements.

The gaseous substance (reactive gas) that forms a reactant with the gaseous substance of these metal compounds may be used alone or in combination.

Further, the objects to be processed used in the present invention include metal materials such as iron and steel, such as chromium molybdenum steel, hot die steel, cemented carbide, Ni, 'I''i, and ceramics.

In the present invention, before coating the reactant by the CVD method using an auxiliary cathode, the surface of the article to be coated is surface hardened, for example, by carburizing, nitriding, boriding, sulfurizing, or carbonitriding.
It was found that the adhesion of the reactant coating treatment was further improved. That is, an example of the coating treatment based on the present invention, in which a combination of surface hardening and coating treatment is preferred, is carried out in the following procedure.

(1) Place the article to be treated and the auxiliary cathode at appropriate positions within the glow discharge container.

(11) Evacuate the glow discharge vessel to 10” Torr or less.

(ii[+H2, or H, 10Ar to 0.1 to 10To
It is introduced into the glow discharge vessel so that the required value of rr is obtained.

(1v) Apply DC between the electrodes to generate glow discharge,
Sputter cleaning is performed on the coated surface of the workpiece facing the auxiliary cathode and heated to the required treatment temperature.

(ψ) CH4 is introduced into the glow chamber, the pressure inside the container is controlled to maintain the treatment temperature, and a carburized layer with a high degree of C is formed on the coated surface of the product to be treated.

(vl) Gaseous form of metal compound dispersed in carrier gas 4
A rostrum, for example (T ict* + H2), is introduced at an equivalent ratio of 1.0 or less to CHa, and the total pressure is mainly H2 or Ar amount to keep the temperature at the required value (H2 in the carrier is fixed). control the required time, usually 0.5~10 hr
% glow discharge treatment.

(Vi+) Next, the supply of gas and the application of DC are stopped, and the pressure of the glow discharge vessel is reduced to 10-"I'orr or less and cooled.

In the present invention, if the auxiliary electrode is configured so that the temperature on the side facing the processed part of the workpiece is sieved compared to the temperature on the opposite side, the energy of glow discharge can be effectively used. You can also.

Furthermore, by exposing the coated portion of the article to at least two types of glow discharge treatment conditions, the article can be subjected to a plurality of types of treatments.

Moreover, by exposing two or more coated parts of the treated article to different glow discharge treatment conditions, it is possible to provide parts with multiple types of functions to one treated article.

Auxiliary electrodes with discontinuous surfaces such as holes, slits, etc. can also be used to improve the supply of reactive gases and to improve gas retention between the auxiliary electrode and the workpiece.

[Embodiments of the Invention] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

A film is formed on the surface of the quaternary treated product. First, the surface may be sputtered to coat the target atoms singly or in combination, but first the surface has functions such as lubrication, corrosion resistance, fatigue resistance, etc., and then the coating is formed. It is desirable to In this case, in order to provide the product with functionality without adversely affecting it, the atomic weight and depth of the diffusion or adsorption must be appropriate, and the surface concentration must be constant (generally, the solid solubility limit of the material or the adsorption The processing temperature plays an important role. Here, taking surface hardening of steel materials as an example,
When surface hardening is carried out with desired elements, generally 400 to 700C
is within the range of Surface hardening in carburizing process using carbon hardens at 700-1100C, and hardening at 800-1200C
2: Become. On the other hand, the treatment for causing membrane rupture on the surface varies depending on the atom, but is in the range of 500 to 1200 iC. In this way, if a hard layer is formed on the surface of a material and then a superhard coating layer such as TiC or HfC is formed on that surface, a material that is resistant to deformation and has excellent durability can be obtained. It will be done.

As mentioned above, there are appropriate processing temperatures and processing times depending on the atoms to be diffused or coated and the material of the object to be processed. Although it is possible to use an external heat source to efficiently raise the surface temperature of the workpiece or (c) to heat it to a topically appropriate temperature, in the present invention, the workpiece and the 'L is an auxiliary cathode of about NId, which is placed on the cathode side at a predetermined distance 1ii1 from the surface of the workpiece, and by controlling the type of pressure of the gas introduced during the coating process. A reaction is carried out by generating a hollow cathode effect between the electrode and the object to be processed, within or between the auxiliary cathodes. Here, heat absorption by the processed item is due to heat exchange of glow discharge energy and radiant heat from the processed item and electrode, and heat loss due to heat release is due to radiant heat, convection of reactive gas, and heat from the electrode. heat conduction (outflow from the electrode cooling water), etc.

Note that the hollow cathode effect occurs when two negative glow discharges are brought close to a certain distance t411, and they interact with each other, and the ionization density of the glow discharge part of the pond also becomes 5, and the discharge Even though the rising pressure is low, the temperature is higher than that on the other side. What can be used to heat the required portion of the workpiece to a predetermined temperature is mutual radiant heat from discharge energy between the auxiliary cathode and the workpiece. this is,
The cathode spacing was set at a constant interval, and the introduced reactive gas pressure was 19F.
This can be achieved by setting a constant value to create a hollow cathode effect between the two cathodes or between the cathode and the workpiece, and increasing the current density on other glow surfaces.

In addition, if there are multiple surface areas on which you would like to impart different functions to different parts of the product, you can install multiple cathodes accordingly and change the gap, shape, and material of each cathode, as necessary. By controlling the type and pressure of the reactive gas introduced, multiple functional aspects can be obtained. The ionization density of the gas between the auxiliary electrode and the auxiliary cathode on the surface of the product in these parts is increased, and the target diffusion or surface reaction with the active atoms to be coated becomes active. In order to effectively carry out this phenomenon, important factors are the distance from the surface of the workpiece to the auxiliary electrode or the spacing within the auxiliary cathode, the setting of the gas pressure according to the material, shape, area, and gas composition. . First, the distance from the surface of the workpiece to the auxiliary electrode or the spacing within the auxiliary cathode varies depending on the reactive gas pressure, but the negative glow generated between the workpiece and the installed auxiliary electrode is Unless interaction occurs and a hollow cathode effect is generated, the desired effect will not occur. This is because the effective gap in which the negative glow influences each other varies depending on the gas composition and gas pressure, and this strongly influences the hollow cathode effect. Furthermore, the shape and structure of the auxiliary cathode 11, which are closely related to these factors, are also important factors.

FIG. 1 shows the structure of a plate-shaped auxiliary cathode. The auxiliary cathode 11 is on the anode side, and the auxiliary cathode 12 is on the workpiece side. In this treatment method, the cathode spacing is 1. is an important factor. In particular, the structure is such that the auxiliary cathode 12 has a higher temperature than the auxiliary cathode 11 within the cathode. The hollow cathode effect is generated between the cathodes, that is, between the auxiliary cathode 11 and the auxiliary cathode 12, or between the auxiliary cathode 12 and the object to be processed. Further, the cathode structure may be cylindrical as shown in FIG. In this case, the auxiliary electrode 22 or 23 is the auxiliary electrode 2
It is thinner than 1 and may be attached to 21 as a smaller piece. Next, the distance t between the auxiliary cathodes, or the distance t between the auxiliary cathodes and the workpiece, is determined by the general coating.
When this distance becomes less than 0.5 mm,
There is a tendency for the reaction of the processing gas to the object to be processed to be inhibited.
On the other hand, when the distance is 50 degrees or more, the effect of the hollow cathode effect between the glows becomes weaker, the heating effect due to radiant heat between the auxiliary polarization or the object to be processed decreases, and the process becomes similar to that of a normal CVD method.

Here, using a mixed gas of nitrogen gas, hydrogen gas, argon gas, and methane gas, a glow center was generated at a pressure of 3.5 Torr. In Fig. 1, t is 30rn
m, and if the distance between the cathode 12 and the workpiece is arbitrarily changed (b), and in Fig. 2, t2f: 10 mm, and ``11'' is arbitrarily changed, the distance between this and the workpiece is 8Wt!n. In the case of 0, the temperature of the workpieces was measured by applying the same voltage to the workpieces with a diameter of 15mm x length of 50cm in the same furnace.Figure 3 is a graph showing the relationship between the interval and temperature. It is.

The temperature of a conventional glow tube without an auxiliary electrode is 570C as shown in A, but when the auxiliary cathode shown in Figure 1 is used, it becomes as shown in B, and a hollow cathode effect occurs. Between 2 and 7 ttrm, it is heated to a temperature of 900C or more. Further, when the auxiliary electrode shown in FIG. 2 is used, the temperature becomes as shown by curve C in FIG. 3, and the temperature in the hollow cathode discharge section is 3000 times higher than that in the case without the auxiliary electrode. This temperature difference varies greatly depending on the gas composition, gas pressure, auxiliary electrode material, shape, thickness, etc.

As mentioned above, in order to heat each individual part or a specific position of each part using the hollow cathode effect using an auxiliary electrode on a test piece of about 15 mm in diameter x 50 mm in length, a hollow cathode is used. It can be seen that the distance at which the effect is produced is desirably in the range of 0.5 to 10 mm, preferably 1.5 to 9 mm. Next, regarding the structure of the auxiliary electrode, a similar experiment is performed using the structure shown in FIGS. 1 and 2, with the cathode 11 on the surface facing the anode being thicker than the cathode 12 on the side of the processed product. Although it depends on the difference in thickness between each, the thicker the cathode 12 is, the less the temperature difference force is for the same power consumption, and it is desirable to have a structure in which the temperature of the cathode 12 is higher than that of the cathode 11. Ta.

In addition, a cylindrical conductive article with a diameter of 50mm and a height of 90mm was used, and a thin plate auxiliary cathode with a diameter of 70mm was arranged concentrically, and a case where this auxiliary cathode was not used was examined under the above gas conditions. Voltage when applying voltage at 2.5 Torr,
The relationship between current, output, and temperature was determined as shown in Figure 4. In FIG. 4, the solid line indicates auxiliary polarization, and the broken line indicates no auxiliary electrode.

It can be seen from FIG. 4 that by using auxiliary polarization, a high temperature can be obtained with a low voltage, and the values of processing current and output can also be reduced.

In order to uniformly distribute the reactive gas used in the present invention on the surface of the workpiece, rotary gas distributors 51 to 53 shown in FIG.
Alternatively, the method shown in FIG. 6 in which the workpiece and the auxiliary electrode are rotated together is used.

In FIG. 5, the gas distributors 51 to 53 are provided with reactive gas supply holes 51A, 5113, and 51C, respectively.

In FIG. 6, a cylindrical auxiliary cathode 61 is placed at the second rotation 62'', and a workpiece (not shown) is placed on this auxiliary cathode 61.
will be placed in Further, a rotary gas distributor 63 is provided on the auxiliary cathode 61, and a voltage is applied between the anode 64 and the rotating cathode 62, and reactive gas is introduced from the gas distributor 63 and discharged from the exhaust hole 65. Glow discharge is generated to produce a hollow cathode discharge effect between the auxiliary cathode 61 and the workpiece.

In addition, as shown in FIG. 7, flat plate-shaped auxiliary electrodes 71, 72
are arranged facing each other, and a conductive member 73 is arranged between the auxiliary polarizations 71 and 72. This occasion, +'rli Suke Kougoku 71
, 72 is provided with an insulating layer or a ceramic layer 74 having a heat retaining property at a location other than the opposing surfaces, an effect on power consumption can be obtained.

An example of the arrangement of a plurality of objects to be processed in the present invention is shown in FIGS. 8, 9, and 10.

In FIGS. 8 and 9, a plurality of cylinders of objects to be treated 82 are arranged in a concentric ring shape inside an ion surface treatment apparatus 81, and auxiliary electrodes 83, 84 with concentric ring-shaped parallel surfaces are arranged on the inner and outer peripheries.
It is arranged. This auxiliary electrode 83, 84 and the object to be processed 8
2 are designed to rotate together. 85 is an anode terminal, 86 is a cathode terminal, 87 is a reactive gas inlet, 8
8 is a gas exhaust port connected to a vacuum device, and 89 is a vacuum gauge terminal.

In FIG. 10, an auxiliary electrode 101 and an auxiliary electrode 102 are arranged in parallel, and a flat workpiece 103 is arranged on the side of the auxiliary electrode 102 with a space therebetween. By providing a plurality of such three-way arrangement states, it is possible to process a large number of flat plate-shaped objects at once.

Example 1 Using an ion surface treatment apparatus as shown in FIG.
C coating treatment was performed. The product to be processed is hot die steel JIS
5KD61 steel (diameter 20 mm, length 50 mm and diameter 7 body,
A stepped shape with a length of 30 mm was used. Auxiliary electrode 112
The width is 150mm, the length is 300m++, and the thickness is 5mm.
U8304, as shown in Fig. 11, 50w
Two pieces were placed facing each other at an interval of wL, and three pieces of the workpiece 113 were placed in the center. In addition, in this Figure 11, 1
14 is a reactor, 115 is a power source, 116 is an anode terminal, 11
7 is a cathode terminal, 118 is a gas cylinder, 119 is a gas inlet, 120 is a vacuum device, 121 is a trapper, and 1122 is a metal evaporation source. Note that the tip of 119 is provided with a rotary gas distributor shown in FIG.

The process is first performed using a vacuum device 120 at 10-2 Torr.
After reducing the pressure 17 to r, H, CH, Ar gas was introduced, and 600V was applied from the DC power supply 15 to generate a glow center.After carburizing at 900C for 10 minutes, a carrier gas was added to this gas. TtCA4 dispersed in H6 was mixed and coated at 930C for 30 minutes. The partial pressure of each gas is H, 0, 0, 5 Torr, Ar, 0.9 Torr
,CH4,0,9Torr*T ict,,0.11
Torr sb, gas flow rate is 5.5t/min in total.

Although the treatment is at the same temperature, it is a process similar to the conventional ion nitriding treatment without using an auxiliary electrode, and the auxiliary electrode 112 of the present invention.
A process using . As a result, in the process according to the present invention, as shown in FIG.
On the other hand, with the conventional method that does not use an auxiliary electrode, it is not possible to obtain a uniform temperature in the stepped part, and even in the part between the diameters of 7 mm heated to 930C, the iCC coating was formed. No film is formed, and the film part is also 12th.
As shown in the figure, the film was non-uniform.

filjK scum partial pressure eHt, 0.33 Torr,
Ar.

0.67 Torr, CH4,0,67 Torr,
When treated under the same conditions as in Example 1 except that Ti (t4.0.83 Torr and total gas flow rate 7.5 t/min), a soft soot-like coating was formed.
A good TiC4 coating was not obtained.

Example 2 Figure 13 (a), (b), (c), (d), (
As shown in P)-, the test piece was set inside the ionic surface treatment apparatus shown in Figure GL1. In FIG. 13, the article to be treated (test piece) 131 was a JIS standard SCM415 chromium molybdenum steel 7 shaft (diameter: 15 mm, length: 200 mm). The auxiliary electrode is cylindrical in FIG.
The distance between 32 and 133 is 8 mm, and 132 and test piece 13
1 and the interval is 5, and the hollow cathode discharge is 132.
and test piece 131.

In FIG. 13(b), the auxiliary electrode 135 is made thicker than 134, and the interval is set to 3.5 fins, and a hollow cathode discharge is generated here. FIG. 13(C) shows the top of the test piece 131;
Hollow cathode discharge is generated at the bottom between 138 and 137 at the upper end and between 139 and the test piece 131 at the lower end. Figure 13(d) shows 140 as test piece 1.
31 was also made thicker, and a hollow cathode discharge was generated between 140 and 131.

In FIG. 13(e), hollow cathode discharge was generated between 132 and 133 at the upper end and between 136 and 137 at the lower end. As a result, the upper and lower ends of (a) and (b) in Fig. 13,
(e) is heated to a temperature of 850-950C at the upper end;
680 to 700t in Fig. 13(b);, Fig. 13(d)
) is 670-690C, and the lower end of Fig. 13(e) is 6
The temperature ranged from 50 to 670C.

Here, treatment was performed for 1 h in a CH, 1-i-i, + argon atmosphere, and then TiCt4 gas dispersed in H2 was further mixed as a carrier gas, a treatment of 30 ml was performed, and a rapid cooling treatment was performed.

Each cuff', (0 partial pressure is Hz, 0.77'forr
, A r.

0.70 Torr, CH4,0.94 Torr,
TiCl2.0.07 Torr, and the total gas flow rate is 5.3 t/min.

FIG. 14 shows the measurement results of the hardness distribution after coating treatment. As a result, the hardness of the parts other than the surface coating is in the range I for those heated to 850C or higher, and in the range ■ for the others. The state of the surface coating was the same as in Example 1, with TiC being formed in the range where carburization was uniformly performed by heating to 850C or higher. As described above, it can be seen that the hollow cathode discharge test piece or one generated near it is extremely effective for curing and film formation. FIG. 15 shows an example of an auxiliary electrode. When only the cylindrical inner auxiliary pole 152 with a diameter of 26 mm, a length of 150 mm, and a wall thickness of 3 mm is used for a round rod-shaped workpiece 151 with a diameter of 20 mm and a length of 200 mm, and a cylindrical inner auxiliary pole 152 with a diameter of 36 mm and a wall thickness of 5 mm is used. In the case of the inner side electrode 143, as shown in FIG. 16, a cylindrical inner auxiliary electrode 161 with a diameter of 26 mm and a wall thickness of 3 ff+H is provided with holes of 1 mm, 2 rum, and 3 mm in diameter sequentially on the entire surface, and On the outside of this auxiliary electrode, four types of external auxiliary polarization 162 with an inner diameter of 36 mm and a case where no electrode is used were prepared using nitrogen gas, hydrogen gas, argon gas, etc. in the apparatus shown in FIG. The part without the auxiliary electrode was maintained at 580C with a mixed gas of methane gas, and the temperature of the auxiliary electrode part was measured by varying the gas pressure. FIG. 17 shows the relationship between gas pressure and temperature distribution. In order to stably perform surface treatment using ions, it is important that the temperature of the object to be treated does not change significantly even with slight fluctuations in gas pressure. If there is no auxiliary electrode,
580tZ', but with the conventional single auxiliary electrode, the first
As shown at 121 in Fig. 7, the temperature is high within a relatively narrow pressure range only within the range where hollow cathode discharge is generated between the product and the workpiece. If external polarization is used for this, the curve becomes like the curve 131 in FIG. 17, and the hollow cathode effect also occurs between 152 and 153 in FIG. 15, which is within the polarization range, and its effect can be seen.

On the other hand, when holes with a diameter of 1 to 3 mm are provided in the electrode in the correct order as in the present invention, the temperature at maximum heating becomes low as shown by curve 141 in FIG. The range becomes wider. In this case, due to pressure fluctuations, a hollow cathode discharge occurs in the hole in the auxiliary polarization according to the pressure, which widens the pressure range of the hollow cathode discharge with the workpiece. I am by. next,
When this electrode is further provided with an outer electrode (FIG. 17), the curve becomes like the curve 151 in FIG. 17, and as the maximum temperature becomes higher, the pressure range within which the temperature can be maintained also becomes wider.

Note that the maximum temperature and the pressure range in which a constant temperature can be maintained can vary greatly depending on the shape and structure of the auxiliary electrode and the composition of the gas. .

Next, as electrodes with the structure shown in Figure 16, diameters of 0.5 to 3 mm and 4 mm
, 5, 6, 7, 8, 9 pharyngeal foramen? The size of the pores was investigated using internal auxiliary electrodes provided sequentially. the result,
It has been found that when the maximum pore size is 4 mm or more, the maximum heating temperature decreases rapidly, and when the maximum pore size is smm or more, the effect is significantly reduced. The most effective range is a diameter of 0.5 to 48, and a range of 0.5 to 7 is also effective to some extent. next,
A slit with a length of 20 mm was provided instead of a hole. In this case as well, if the slit width was within 4 rran, discharge based on the hollow cathode effect similarly occurred within the slit. Next, a similar experiment was conducted with a ceramic layer provided on the outside of the electrode. As a result, it was found that in the case of an electrode having the shape shown in FIG. 16, in which ceramic was provided on the outer electrode, the electrical output could be reduced by approximately 10%.

Example 3 JISSKD with cross-sectional dimensions of 15mm x 15mm and length of 120mm
I material was used, and two types of electrodes shown in Fig. 15 and Fig. 16 were used, and three electrodes each were used as nitrogen gas, methane gas, hydrogen gas, argon gas, and carrier gas of 1 to 4'l'' orr. Coating was carried out in the same manner as in Example 1 using CrC1 dispersed in H7.The partial pressures of each gas were l-12,
1.21 Torr.

A r, 0.56'l'orr, CH4,1,13
Torr.

CrCl2.0.08 Torr, and the total gas flow rate is 5.3 t/min. However, the temperature at the position where the hollow cathode was not centered was maintained at 950 C for 30 minutes, and its cross section was observed. As a result, in the method according to the present invention, a Cr carbide film with a thickness of 7 to 10 μm was uniformly formed on the hollow cathode portion.

Example 4 Using the ion surface treatment apparatus shown in Fig. 11, the workpiece to be treated was WC-based carbide, JISSU, with a diameter of 20 mm and a length of 30 mm.
Using S304, this surface has an inner diameter of 36 mm and a wall thickness of 5 tn.
A graphite auxiliary electrode of m is installed 1fL7ζ so that the object to be treated is centered. In this state, f: 10-”'
After decreasing IE L i'j to l'orr, H, +5%A
r gas was introduced, and the flow rate was adjusted so that the pressure was 3 Torr. Thereafter, DC 800V was applied.

The auxiliary electrode part had a strong glow discharge and was heated to 950C in about 15 minutes. In this state, N and gas were introduced at a flow rate of 30% of H1 + 5% Ar, and the overall pressure was adjusted by controlling the flow rate to maintain the temperature at 950C (Ht + Ar) for about 10 minutes. Nitriding treatment was performed. In this case N
, the entire electrode and jig in which the article to be treated was set were rotated at a rate of 1 rotation per minute. After that, H, gas as carrier gas, TiCl2 as H, carrier amount as N, gas as 1
/2 flow rate, control the total pressure, 95
Control the H7 + 5% Ar flow rate to maintain 0C,
Processing was performed for 0 minutes. At this time, the electrode and jig on which the object to be treated was set were rotated at 3 revolutions/minute. After cooling, the cross-sectional structure of each treated product was observed, and it was found that 5 to 10
A TiN film of μm thickness was formed. A process similar to this process was performed without rotating the workpiece. the result,
It was found that the TiN film was formed in a thickness of 3 to 7 μm depending on the set position of the article to be processed, and was found to be 3 to 7 μm near the gas supply port, but was hardly formed in other areas.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing the structure of the auxiliary electrode used in the present invention, Fig. 2 is a perspective view showing another example of the auxiliary electrode used in the present invention, and Fig. 3 is a perspective view showing the structure of the auxiliary electrode used in the present invention. A graph showing the relationship between the distance from the object to be processed and the temperature. Figure 4 is a graph showing the effect of the auxiliary electrode on heating. Figure 5 (a).
(b) and (d) are schematic structural diagrams of a rotary gas distributor for uniformly distributing reactive gas, respectively, and Figure 6 is a schematic structural diagram of a rotating auxiliary electrode for uniformly distributing reactive gas. 7 is a perspective view of a main part showing one aspect of the configuration of the glow discharge treatment apparatus of the present invention, and FIG. 8 is a perspective view of a main part showing a bad aspect of the structure of the glow discharge treatment apparatus of the present invention, and FIG. Figures 9(a) and CI)) are a partial cross-sectional view and a partial vertical cross-sectional view of Figure 8, respectively, and Figure 1O is an arrangement diagram of a workpiece when processing a large number of flat workpieces at once. FIG. 11 is a schematic diagram showing the configuration of the ion surface treatment apparatus of the present invention, FIG. 12(a), (
b) is a micrograph showing the metal structure of the processed product when the present invention process and the conventional process were applied, FIG. 13(a),
(b), (c), (d), and (e) are cross-sectional views showing the auxiliary electrodes used in the present invention, respectively. , a graph showing the relationship between the distance between the object to be processed and the auxiliary electrode, FIGS. 15 and 16 are cross-sectional views showing the structure of the auxiliary electrode used in the present invention, and FIG. 17 is a graph showing the structure of the auxiliary electrode used in the present invention. ? FIG. 3 is a diagram showing the relationship between the increased gas pressure and temperature. 11.12, 21, 22, 23, 61, 71°72.8
3,84,101,102,112゜132.133,
134, 135, 137, 138° 139... Auxiliary electrode.゛・Kanisu 14゜Kaya! Eye 3rd Eye Distance (1st 4th. Solid Temperature (Sumo 5th Eye (f-) (C) $7 Eye $8 Eye δ6 Kaya 7 Mouth (Long) $70 Figure Kaya No. 1 Huge] 12θ Kaya 72 Tsukuotsu (b) Chi 13 Snake (Phantom Lead) (Su / 36 / 36 Bud 74 Solid Distance (Sale) Reed 150 Chi 76 Eye Haya 17 Fig. yoke force °゛ Pressure 7 JC 7,,, Ji Procedural amendment (method) Mr. Kazuo Wakasugi, Commissioner of the Patent Office, 41'F indication 1981'IIl;, Vl: 1 head No. 178325 -
The name of the invention is the person who corrects the method and device for deterioration caused by electricity.
Number 1 Name (j, L51111 Co., Ltd. (111 Manufacturing Co., Ltd. Representative Matsu 31) Katsu Shigeyo Osamu Address Address 5-chome Marunouchi, Chiyoda-ku, Tokyo No. 1 Brief description of the drawings of the specification subject to the amendment Column. Contents of amendment 1, specification il) Page 38, line 5 [Figure 5 (a),
(b), (d) J to "Figure 5 (a), (b)
, (C) amended to J.

Claims (1)

[Scope of Claims] 1. An electrically conductive treated object connected to a cathode at a vacuum level of 10 Torr or less, containing a gaseous substance of a metal compound and a reactive gas that reacts with the metal compound to form a reactant. A method for coating the surface of the article with a reactant by generating a glow discharge between the anode, an auxiliary cathode, and an anode, which are disposed close to a position where glow discharge interaction occurs on the article, . A coating method by glow discharge, characterized in that the partial pressure of the gaseous substance is smaller than the partial pressure of the reactive gas. 2. In claim 1, the coating method by glow discharge characterized in that the partial pressure of the gaseous substance of the metal compound is 0.5 Torr or less, and the partial pressure of the reactive gas is 1 Torr or more. . 3. In Claim 1, the gaseous substance of the metal compound is T I r Cr* N 1 r Si+
A Z sZr, B, Hf, V, W, or Ta halide, the reactive gas is CH, N, silane or borane, and the reactant is a nitride of the above metal. A coating method using glow discharge, characterized in that it is a carbide or a boride. 4.% Allowance In claim 1, the gaseous substance of the metal compound is dispersed in a carrier gas by blowing a carrier gas consisting of a non-oxidizing gas into the storage liquid of the metal compound. A coating method using glow discharge characterized by: 5. A coating method using glow discharge according to claim 4, characterized in that the carrier gas is a water bed, the metal compound is 'rict, and the reactive gas is CH4. 6. A coating method using glow discharge according to claim 1, characterized in that the surface of the article to be treated is surface hardened before the coating treatment. 7. The coating method by glow discharge according to claim 6, wherein the surface hardening is any one of carburizing, nitriding, boriding, flooding, or carbonitriding. 8. In claim 1, the degree of vacuum is 2 to 7.
A coating method using glow discharge characterized by 'I'orr. 9. An anode, a cathode, an auxiliary electrode, such as a conductive workpiece connected to the cathode, disposed close to a position where glow discharge interaction occurs with the workpiece, and a reactive gas immersion source. , a reactive gas outlet, and a glow discharge coating device, which reacts with the partial pressure of the gaseous substance of the metal compound fed into the device to form a reactant. A coating device using glow discharge, characterized in that it is provided with pressure adjustment means for adjusting the partial pressure of a reactive gas. 10. Claim 9, characterized in that the pressure regulating means is a means for moving the supply direction of the reactive gas and the coating treatment surface of the article to be treated in tandem. Coating device using glow discharge. 11.% Allowance In claim 10, the means comprises:
A coating device using glow discharge, characterized in that it is a rotary reactive gas distributor. 12. In claim 10, the means comprises:
A coating device using glow discharge, which rotates the object to be treated integrally with the auxiliary electrode. 13. The coating device using glow discharge according to claim 9, wherein the distance between the object to be treated and the auxiliary electrode is between 0.15 and 0.50.