JPH10204613A - Apparatus for producing composite powder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus for producing composite powder having high reliability. SOLUTION: This apparatus for producing the composite powder has a tray- shaped powder vessel 4 which is inclined at about a predetermined angle of inclination with a perpendicular line and is loaded with raw material powder on the inner side, targets 8 which are installed to face this powder vessel 4, produce composite powder and coat the powder surface with this composite powder by executing vacuum vapor deposition, a vacuum vessel 3 which houses the targets and the powder vessel and is internally kept at a vacuum or inert gaseous state, an evacuation device 1 which is connected to this vacuum vessel 3 and evacuates the inside of the vacuum vessel 3 and a driving device 5 which is connected to the powder vessel 4 and applies mechanical motion to the powder vessel 4. As a result, the productivity of the apparatus for producing the composite powder is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to powder metallurgy, and more particularly to a composite powder manufacturing apparatus for manufacturing and manufacturing a composite powder in which a trace element or substance is uniformly added to a raw material powder.

[0002]

2. Description of the Related Art Conventionally, in the field of powder metallurgy, compounding of functions has occupied an important position. For this reason, the production method of composite powder has been remarkably developed. Tend to be relatively easy to produce. In particular, many methods have been disclosed for surface coating on powder. For example, JP-A-58-3107
6, as described in JP-A-61-30603,
A method in which powder is placed in a container and a film is uniformly formed on the surface of the powder by vibration, or as described in JP-A-56-130469, a method in which the powder is uniformly vibrated on an inclined flat plate by a sputtering method. Discloses a method of forming a film on a substrate. However, all of these proposals have focused on the homogeneity of the film on the powder surface, but at present, sufficient homogeneity has not yet been obtained.

Further, the purpose of coating the raw material powder with other components is to improve wettability with other components generated in a later step,
Suppression of the reaction, addition of a small amount, etc. can be mentioned, but mere coating is not enough to achieve these, and the adhesion between the raw material powder and the coating material and the increase of gas components such as oxygen due to the coating are also complex. Be evaluated as a powder. From these viewpoints, the function was not sufficiently satisfied.

[0004]

SUMMARY OF THE INVENTION The present invention provides a more uniform surface coating of the powder surface, further strengthens the bonding between the raw material powder and the coating material, and further increases the content of gas such as oxygen. It is an object of the present invention to provide a composite powder manufacturing apparatus capable of remarkably suppressing the generation of the composite powder.

[0005]

According to a first aspect of the present invention, there is provided a composite powder producing apparatus, comprising: a dish-shaped powder container in which a raw material powder is mounted on the inside by being inclined at a predetermined inclination angle with respect to a vertical line; A target that is installed opposite to the container and performs vacuum deposition to produce and coat a composite powder on the surface of the powder body, and a vacuum container that stores the target and the powder container and maintains the inside in a vacuum or inert gas state. A vacuum exhaust device connected to the vacuum container to evacuate the inside of the vacuum container; and a drive device connected to the powder container to apply mechanical movement to the powder container.

That is, the present invention is characterized in that the surface of a powder body is coated by a vacuum deposition method in a state where the powder container into which the raw material powder is charged is inclined and mechanical movement is given.

[0007] The composite powder manufacturing apparatus according to claim 2 is
It is characterized in that the mechanical movement includes any of a rotational movement and a vibration movement.

[0008] The composite powder production apparatus according to claim 3 is
The mechanical movement includes one of a pulse rotation movement and a pulse vibration movement.

[0009] The composite powder producing apparatus according to claim 4 is
It is characterized in that the inclination angle can be set by adjusting the flow angle of the raw material powder to any one of 0 ° to 90 ° which can sufficiently control the flowability.

[0010] The composite powder production apparatus according to claim 5 is
It is characterized in that the inert gas state is a low-pressure argon sealed state. That is, the vacuum deposition method is a sputtering method using a DC power supply and / or a high-frequency power supply, and is characterized in that the sputtering atmosphere is a low-pressure Ar (argon) atmosphere.

The composite powder manufacturing apparatus according to claim 6 is
A heating device attached to the powder container is provided, and vacuum deposition is performed while the powder container is heated.

A composite powder manufacturing apparatus according to claim 7 is
It is provided with a cooling device attached to the powder container, and after coating by vacuum evaporation, is cooled in a high vacuum atmosphere of 10 ⁻² Pa or more until the temperature of the vacuum container becomes 400 ° C. or less.

The composite powder manufacturing apparatus according to claim 8 is
After coating by vacuum deposition, the composite powder is heat-treated at a temperature not higher than the melting temperature of the composite powder and in a high vacuum atmosphere of 10 ⁻² Pa or more.

According to a ninth aspect of the present invention, there is provided an apparatus for producing a composite powder,
After coating by vacuum deposition, the composite powder is heat-treated in a non-oxidizing atmosphere at a temperature not higher than the melting temperature of the composite powder.

The composite powder manufacturing apparatus according to the present invention is characterized in that an exhaust valve is provided in a connection pipe connecting between the vacuum vessel and the vacuum exhaust device.

An eleventh aspect of the present invention is characterized in that a leak valve is provided in a connection pipe connecting between the vacuum vessel and the evacuation device.

As described above, the object of the present invention is to (1) uniformly coat the surface of the raw material powder, (2) improve the adhesion between the raw material powder and the coating material, and (3) suppress the gas content. There are three main points to do.

First, a method of uniformly coating the surface of the powder is described. However, the raw material powder (or the powder) is simply placed in a container and simply vibrated to cover the entire surface of the powder. However, a nonuniform coating amount occurs at a position in the container depending on the target diameter of the sputter. In addition, in the method of performing sputtering while dropping powder on a flat plate, there is a problem that a sufficient amount of sputtering cannot be obtained.

From such a viewpoint, it has been found that a method of rotating the powder container while tilting the powder container is desirable. According to this method, by setting a predetermined inclination angle, the powder can be uniformly dispersed on the surface of the container, or the powder can be moved to an area where the movement of the powder is opposite to the moving direction of the bottom of the container. It is also easy to collect and collect the powder in the same area as the movement direction of the powder on the bottom surface of the container.

In addition to forming such various states, the movement of the powder is made more active by applying vibration to the container and making it rotate in a pulsed manner, so that the powder surface can be uniformly mixed with the raw material powder. Coating can be added.

Next, regarding the adhesion between the raw material powder and the coating material, it is an existing technique to heat the substrate in a usual sputtering method. According to this technique, when a foreign substance is adhered to the surface of a powder, a poor adhesion portion rarely occurs because the surface is not always smooth or a uniform temperature distribution cannot be obtained. In order to suppress this, in the present invention, after coating the raw material powder, high-temperature heat treatment is again performed in a non-oxidizing atmosphere in the apparatus, or the coated powder is inertized in another heating furnace. It has been found that by performing heat treatment again in an atmosphere, the degree of adhesion between the raw material powder and the coating material can be improved.

Next, as a means for suppressing the increase in the gas content due to the coating step, a method was found in which, immediately after the coating step was completed, a method of cooling to a temperature at which oxidation does not proceed immediately after the completion of the coating step was performed under a high vacuum.

One of the features of the present coating method is that, as described above, the powder is controlled (controlled) at an arbitrary position in the container.
This means that the rotation of the container is set to pulse rotation together with the vibration mechanism from the viewpoint that the inclination angle can be set in a white manner in terms of the device.

A further object of the present invention is to load a heating source on the container in order to strengthen the adhesion between the powder and the coating layer, and to add a cooling mechanism for suppressing gas components.

Further, a feature of the present invention is to provide a slow leak valve and a slow exhaust valve in order to suppress the powder from flowing out to the vacuum pump system during evacuation of the fine powder. It is also useful to provide a wire net or the like at the interface between the exhaust system and the powder container in order to increase the conductance.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of a composite powder producing apparatus according to the present invention will be described. FIG. 1 is a configuration diagram of a composite powder manufacturing apparatus, and FIG. 2 is an explanatory diagram illustrating the principle of powder movement. In FIG. 1, it is a dish-shaped apparatus in which the raw material powder is mounted on the inside of the powder container 4 at a predetermined inclination angle θ with respect to the vertical line K.

The target 8 is an electrode device which is installed opposite to the powder container 4 and performs vacuum deposition to produce and cover a composite powder on the surface of the powder. The vacuum container 3 is a container that houses the target 8 and the powder container 4 and keeps the inside in a vacuum or in an inert gas state. The evacuation device 1 is connected to the vacuum vessel 3 with a connection pipe.
Used to evacuate the interior of the

The driving device 5 is a device which is connected to the powder container 4 via a connecting shaft 6 or the like to give a mechanical movement to the powder container 4. A blocking mechanism is provided so that it cannot be closed.

That is, an inner diameter φ45 provided with a vacuum exhaust device 1 and a guide portion 2 for guiding an inert gas such as argon.
A powder container 4 having an inner diameter of about 300 mm is installed in a vacuum container 3 having a diameter of about 0 mm. The powder container 4 is connected to a driving device 5 that is attached below the powder container 4 and applies rotation or vibration. When the powder container 4 is rotated or vibrated by the driving device 5, The powder charged in the container 4 flows.

A target 8 having electrodes is installed as a vacuum evaporation mechanism facing the powder container 4, and a power supply 7 using a high-frequency power supply RF or a DC power supply DC is connected to the target 8. I have. The target 8 and the powder container 4 are stored in the vacuum container 3.

A heating device 9 and a cooling device 10 are attached to the lower surface of the powder container 4 using a heater or the like, and function to enhance the effect of vacuum deposition. Further, a leak valve 12 such as a slow leak valve and an exhaust valve 11 such as a slow exhaust valve are provided between the vacuum vessel 3 and the vacuum exhaust device 1 to improve workability of vacuum exhaust and inert gas. Used for

Further, at the boundary between the vacuum vessel 3 and the evacuation device 1, a wire mesh is provided.
Furthermore, the driving device can also apply intermittent vibration or rotation using a pulse motor or the like. Further, the powder container 3 can have a mechanism for setting the inclination angle θ of the connecting shaft connecting the powder container 4 and the driving device 5 to an arbitrary inclination of 0 to 90 degrees with respect to the vertical line.

Hereinafter, the evaluation method of the embodiment of the present invention will be described.

(1) Coatability of Powder An arbitrary powder was sampled and quantitatively analyzed at any five locations by an EDX (energy dispersive X-ray apparatus) to examine whether or not the coating component was coated. When the coating was completely recognized, the evaluation was scored as 2 points, when it was slightly recognized as 1 point, when it was not recognized at all as 0 point, and the maximum of the total value was evaluated as 10 points.

(2) Homogeneity of Coating Lot Powder was collected from any three places and the coating components were analyzed by a wet method.

(3) Adhesion of coating components The coated composite powder was sieved through a # 325 mesh (44 μm) sieve, and analyzed in the same manner as in (2). And the difference was evaluated.

(4) Gas Components The raw material powder and the composite powder after coating were each subjected to oxygen analysis and evaluated.

Next, general matters relating to rotation, inclination, and vibration of the container were examined.

Comparative Example 1 An average particle diameter of 100 μm was placed in a powder container.
300 g of Cr (chromium) powder was added, and 1 × 10 ⁻³
After evacuating to a degree of vacuum on the order of Pa, Ar was introduced and a valve of the exhaust system was operated to form a low vacuum on the order of 1 OPa. Then, while the container is not tilted, the powder is moved at a rotation speed of 30 rpm. In this state, an Al (aluminum) target of φ80 mm is used, and a DC power supply of 350 V-0.3 A is used.
60 sputters were performed for 60 minutes.

Example 1 A composite powder was produced under the same conditions as in Comparative Example 1 except that the angle of inclination of the container was 30 degrees.

Example 2 The container inclination angle was set to 30 degrees, and 3
While rotating at a rotation speed of 0 rpm (rotation / minute), 1
A composite powder was produced in the same manner as in Comparative Example 1 except that the pulse rotation was stopped at a rate of Hz (1 / second).

Example 3 A composite powder was produced under the conditions of Example 1 while applying vibration in the axial direction at a frequency of 1 Hz (1 / sec).

Example 4 A composite powder was produced under the conditions of Example 2 while giving an axial vibration at a frequency of 1 Hz (1 / sec).

[0044]

[Table 1]

Table 1 shows the results of these evaluations. In Comparative Example 1 in which the container was not tilted, sufficient results were not obtained in both the coatability and homogeneity of the powder. On the other hand, what rotated the container, what rotated the vibration, what added these vibrations,
All showed good properties. Therefore, the effect of tilting the container is clear.

Next, heating during and after sputtering will be discussed.

Example 5 A composite powder was produced under the conditions of Example 3 while heating the container to 100 ° C.

Comparative Example 2 The powder produced in Example 5 was sputtered in the same container in the same vacuum atmosphere as the sputtering at 500 ° C.
After heating for 2 hours, the powder was taken out.

Comparative Example 3 The powder produced in Example 5 was evacuated to a vacuum of the order of 1 × 10 ⁻³ Pa (Pascal) in the same container, and then heated at 500 ° C. for 2 hours. Thereafter, the powder was taken out.

Example 6 The powder produced in Example 5 was evacuated to a vacuum of the order of 1 × 10 ⁻³ Pa in the same container, heated at 500 ° C. for 2 hours, and then heated to the same pressure. After cooling to 400 ° C. or less in a vacuum atmosphere, the powder was taken out.

Example 7 The powder produced in Example 5 was evacuated in the same container to a degree of vacuum of the order of 1 × 10 ⁻³ Pa, and then heated at 500 ° C. for 2 hours. After cooling to 100 ° C. or less in a vacuum atmosphere, the powder was taken out.

Example 8 The powder produced in Example 5 was evacuated to a vacuum of the order of 1 × 10 ⁻³ Pa in another heating furnace, and then heated at 500 ° C. for 2 hours. After cooling to 100 ° C. or less in the same vacuum atmosphere, the powder was taken out.

Comparative Example 4 The powder produced in Example 5 was evacuated to a degree of vacuum of the order of 1 × 10 ⁻³ Pa in another heating furnace, and then heated at 1000 ° C. for 2 hours. After cooling to 100 ° C. or less in the same vacuum atmosphere, the powder was taken out.

[0054]

[Table 2]

As shown in Examples 3 and 5 and Comparative Examples 2 and 3 in Table 2, the adhesion is improved by heating the container, but the oxygen content tends to increase unless the heat treatment conditions are carefully selected. It has been found. As can be seen from Examples 6, 7, and 8 as a method for compensating for this, it is understood that heating in a sufficiently high vacuum atmosphere and sufficient cooling are important. Furthermore, as shown in Comparative Example 4, if the heating temperature is set to be equal to or higher than the melting point of the composite powder, it can be seen that good composite powder cannot be obtained.

Next, the inclination angle of the container will be examined.

Comparative Example 5 An experiment was performed under the same conditions as in Example 3 except that the container inclination angle was changed to 10 degrees. Example 9 Example 9 was performed under the same conditions as Example 3 except that the container inclination angle was set to 40 degrees. Example 10 Example 10 was performed under the same conditions as Example 3 except that the container inclination angle was 70 degrees.

[0058]

[Table 3]

As can be seen from Table 3, in Comparative Example 5 in which the container inclination angle was small, there was a variation in the coatability probably because the fluidity of the powder was not sufficient. Conversely, in Example 10 in which the container inclination angle was large, the powder was uniformly coated, but the sputtering rate tended to decrease. Examples 3 and 9, which have an intermediate inclination angle between these, exhibited good characteristics. Therefore,
It has been found that there is an effective tilt angle for the powder.

Next, the powder will be examined.

Comparative Example 6 500 g of W (tungsten) powder having an average particle size of 3 μm was charged. And it carried out on the same conditions as Example 3 except the container inclination angle being 30 degrees.
Example 11 The experiment was performed under the same conditions as in Comparative Example 6 except that the container inclination angle was 40 degrees.

Example 12 The experiment was carried out under the same conditions as in Comparative Example 6, except that the angle of inclination of the container was 60 degrees.

Example 13 The experiment was carried out under the same conditions as in Comparative Example 6 except that the angle of inclination of the container was 80 degrees.

[0064]

[Table 4]

As can be seen from Table 4, although there is an absolute difference in the inclination angle, the same tendency as in the above-described Cr powder example was obtained. That is, Comparative Example 6 in which the container inclination angle was small.
It was recognized that the fluidity of the powder was not sufficient and that the coatability was uneven. Conversely, Example 12 in which the container inclination angle is large
Although the powder was uniformly coated, the sputtering rate tended to decrease. Examples 11 and 12, which have an intermediate inclination angle, exhibited good characteristics.

In conjunction with the above-described Cr example, it was found that there was an effective inclination angle for the powder.

Incidentally, Comparative Example 6, Examples 11, 12, and 13
During evacuation and vacuum evacuation without using the slow leak valve provided in the container, the inside of the container was observed. In addition, it has been found that a large amount of powder remains in a vacuum pipe connected to the exhaust system, and that a wire mesh can be provided to suppress scattering of the powder into the vacuum exhaust system.

In this embodiment, only the embodiment using the sputtering method is described. However, it is apparent that similar results can be obtained by another vacuum deposition method such as ion plating.

[0069]

According to the present invention, it is possible to provide an apparatus for producing a composite powder capable of producing a homogeneous composite powder having a high interfacial strength.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a composite powder production apparatus showing one embodiment of the present invention.

FIG. 2 is an explanatory diagram showing the operation of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vacuum exhaust device 2 Introducing part 3 Vacuum container 4 Powder container 5 Drive device 6 Connecting shaft 7 Power supply device 8 Target 9 Heating device 10 Cooling device 11 Exhaust valve 12 Leak valve

Continued on the front page (72) Inventor Atsushi Yamamoto 1 Toshiba-cho, Fuchu-shi, Tokyo Inside the Toshiba Fuchu Plant Co., Ltd. (72) Inventor Takashi Kusano 1 Toshiba-cho, Fuchu-shi, Tokyo Inside Fuchu Plant

Claims (11)

[Claims] 1. A dish-shaped powder container in which a raw material powder is mounted on the inside by being inclined by a predetermined inclination angle with respect to a vertical line,
A target that is installed to face the powder container and performs vacuum deposition to produce and coat a composite powder on the powder body surface,
A vacuum container containing the target and the powder container and keeping the inside in a vacuum or inert gas state, a vacuum exhaust device connected to the vacuum container to evacuate the inside of the vacuum container, and the powder container; A driving device connected to apply mechanical motion to the powder container. 2. The composite powder manufacturing apparatus according to claim 1, wherein the mechanical movement includes one of a rotating movement and an oscillating movement. 3. The composite powder manufacturing apparatus according to claim 1, wherein the mechanical movement includes one of a pulse rotation movement and a pulse vibration movement. 4. The apparatus according to claim 1, wherein the inclination angle can be set by adjusting the flow angle of the raw material powder to any one of 0 to 90 degrees which can sufficiently control the fluidity of the raw material powder.
2. The composite powder production apparatus described in 1. above. 5. The composite powder production apparatus according to claim 1, wherein the inert gas state is a low-pressure argon-filled state. 6. The composite powder manufacturing apparatus according to claim 1, further comprising a heating device attached to the powder container, wherein the vacuum evaporation is performed while the powder container is heated. 7. A cooling device attached to the powder container, wherein after coating by vacuum deposition, cooling in a high vacuum atmosphere of 10 ⁻² Pa or more until the vacuum container becomes 400 ° C. or less. The composite powder manufacturing apparatus according to claim 1, wherein: 8. After coating by vacuum deposition, at a temperature below the temperature at which the composite powder does not melt, and at 10 ⁻² Pa
The composite powder manufacturing apparatus according to claim 1, wherein the composite powder is heat-treated in the high vacuum atmosphere. 9. The composite powder according to claim 1, wherein after being coated by the vacuum deposition, the composite powder is heat-treated at a temperature lower than a temperature at which the composite powder does not melt and in a non-oxidizing atmosphere. The described composite powder production equipment. 10. The composite powder manufacturing apparatus according to claim 1, wherein an exhaust valve is provided in a connection pipe connecting between the vacuum vessel and the vacuum exhaust device. 11. The composite powder manufacturing apparatus according to claim 1, wherein a leak valve is provided in the connection pipe.