JPH0593255A - Method for plasma spraying on substrate - Google Patents

Abstract

PURPOSE:To improve the capacity of plasma spraying and to uniformly form a thin film, at the time of heating a substrate by high frequency induction heating in 7 noncontact and executing plasma spraying, by moving the substrate. CONSTITUTION:Electric power is fed to a high frequency coil 3 from a high frequency power source 4 to generate plasma 5 at the inside of a plasma generating part 2. When a powder sample is charged from the upper charging port 6, this is melted in the plasma 5 and is stuck on the face of the substrate 7. At the time of the above plasma spraying, the substrate 7 is rotated by a rotating apparatus 11. Because the substrate 7 has preliminarily been heated, by the rotation and movement of the substrate 7, the molten sample uniformly sticks on the face of the substrate 7. In the case the substrate 7 is made of a nonmagnetic body such as ceramics, it is permited to incorporate a magnetic body into the substrate 7 and to indirectly heat it.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma spraying method, and more particularly to a plasma spraying method for uniformly depositing a molten sample on a substrate by plasma spraying.

[0002]

2. Description of the Related Art Various methods have been developed for the thermal spraying technique, but in recent years, the plasma thermal spraying method has attracted particular attention. In this plasma spraying method, it is necessary to control the temperature before and after the spraying in order to improve the spraying performance on the substrate to be sprayed, that is, the bonding strength and the denseness.

Conventionally, when plasma-spraying a substrate, an electrothermal heater such as a nichrome wire or a carbon heater is brought into direct contact with the substrate to heat the substrate, or radiant heating using an infrared lamp or the like is used.

[0004]

In the plasma spraying method, metal and non-metal ceramics are used as the material of the substrate, and the substrate is rotated at a high speed in order to improve the uniformity of the deposited film. You need to move it up / down / left / right. From this point, it is structurally difficult to directly contact the electric heater or the like with the substrate, and it is also difficult to perform radiant heating with an infrared lamp or the like in a high temperature state of the plasma flame in the gas atmosphere.

In view of the above-mentioned prior art, the present invention relates to rotation,
It is an object of the present invention to provide a method for heating a moving substrate in a non-contact manner to improve plasma spraying performance.

[0006]

The present invention is a plasma spraying method for heating a substrate in a non-contact manner by high frequency induction heating and performing plasma spraying while moving the substrate. In the present invention, the substrate is heated in a non-contact manner by the high frequency induction heating method. Therefore, heating of the rotating and moving substrate becomes easy. In order to improve the thermal spraying performance on the thermal spraying target substrate, it is necessary to uniformly preheat the substrate before thermal spraying and gradually lower the temperature after thermal spraying. In the conventional technique, it is difficult to perform such temperature control on the substrate that is rotated at high speed or moved vertically and horizontally, but it can be ideally controlled by the high frequency induction heating method of the present invention.

[0007]

In order to form the sprayed thin film on the side surface of the cylindrical substrate, a high frequency coil is wound along the axis of the cylindrical or flat substrate 6 as shown in FIG. 2, and a high frequency current is passed through the coil to heat the substrate. At this time, if the substrate material is not conductive and it is an insulator such as ceramics, insert a magnetic rod along the center of it or place a magnetic plate on the back surface of a flat plate to heat it indirectly. Good. Further, in order to form the sprayed thin film on the head plane of the cylindrical substrate, a solenoid coil is wound around that portion as shown in FIG. 3 and the surface is subjected to high frequency heating.

As described above, if the substrate is heated in a non-contact manner by the high frequency induction heating method, it can be freely rotated and moved even in a high temperature gas atmosphere, so that a thin film can be formed uniformly and ideally at a desired temperature. Can be managed.

[0009]

1 is a schematic explanatory view of an embodiment of the present invention using an industrial high-frequency power source 10 of 400 kHz, 10 kW, 1 is a vacuum vessel, 2 is a plasma generator,
A high frequency coil 3 is wound around the plasma generator 2.
Electric power of 2 MHz and 100 kW was supplied from the high frequency power source 4 to the high frequency coil 3. As a result, the plasma generator 2
A plasma 5 is generated inside the. At this time, when a powder sample is charged through the charging port 6 in the upper part, the powder sample is melted in the plasma and adheres to the surface of the substrate 7. The substrate 7 is a cylindrical substrate, and is rotated in the circumferential direction of the cylinder by a rotating device 11 during plasma spraying. At this time, since the substrate is preheated to an appropriate temperature in advance, the molten sample is uniformly attached on the surface by the rotation (direction A) and movement (direction B) of the substrate 7. When the sample thickness reaches the desired value, the sample injection is stopped, the plasma is stopped, and then the high frequency power source 10 for heating the substrate is gradually lowered to lower the substrate temperature at the required lowering speed.

As shown in FIG. 2, the substrate 7 is heated in a non-contact manner by a high-frequency coil 8 and a high-frequency power source 10 for heating the substrate, which are formed in a cylindrical shape of the substrate. The high frequency coil 8 is separated from the substrate 7 during the deposition of the molten sample by the plasma. FIG. 3 shows a case where the molten sample is attached to the plane of the head of the cylindrical substrate 7. A solenoid high-frequency coil 9 is wound around the heating unit, and a high-frequency current is passed through the solenoid to heat it for rotation (direction A). While being moved, it is moved up and down (direction B) to uniformly adhere to an appropriate thickness.

[0011]

The present invention uses the high frequency induction heating system to
Since the substrate can be heated without contact, it has the following features. 1. It is possible to heat a substrate that is rotating and moving. 2. Heating can be performed in vacuum, in any gas atmosphere, or in a high temperature atmosphere by devising the material of the heating coil, the method of introducing current, and the shape of the coil. 3. In the case of a non-magnetic material such as ceramics, the magnetic material can be incorporated into the substrate and heated indirectly. 4. The substrate can be heated more efficiently than the conventional method. 5. The temperature control of the substrate is simple, and the gradual temperature decrease rate of the processed substrate is easy to control.

[Brief description of drawings]

FIG. 1 shows a schematic explanatory view of an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a case where a generation film is formed on the side surface of a cylindrical substrate.

FIG. 3 is an explanatory diagram in the case of forming a generation film on the head of a cylindrical substrate.

[Explanation of symbols]

 1 Vacuum container 2 Plasma generator 3 High frequency coil 4 High frequency power source for plasma generation 5 Plasma 6 Sample inlet 7 Substrate 8 High frequency coil 9 Solenoid high frequency coil 10 High frequency power source for substrate heating

Claims (2)

[Claims] 1. A plasma spraying method for a substrate, wherein the substrate is heated in a non-contact manner by high frequency induction heating, and plasma spraying is performed while moving the substrate. 2. An insulating substrate, wherein a magnetic material is brought into contact with or included in an insulating substrate to heat the substrate indirectly by non-contact by high frequency induction heating, and plasma spraying is performed while moving the substrate. Plasma spraying method.