JPH04187753A - Wire for thermal spraying - Google Patents

Abstract

PURPOSE:To provide a wire for thermal spraying capable of attaining a homogeneous composite film of desired composition by forming the wire with a base material capable of being thermally sprayed and an additional material for improving the characteristic of the film. CONSTITUTION:A base material 1 capable of being wire-explosion sprayed is coated in its radial direction with an additional material 2, etc., for improving the characteristic of the film to obtain this material for thermal spraying. The additional material 12, etc., are also mixed into the matrix of the base material 11. A conductive material such as piano wire and Mo wire is exemplified as the material capable of being wire-explosion sprayed. Various materials can be selected as the additional material in accordance with the characteristic of the desired film and the kind of the base material, and a high-hardness material represented by a ceramic such as Al2O3 or a lubricating material such as carbon and boron nitride is used. A homogeneous composite film, in which the distribution of the additional material in the base material is sufficiently controlled, is obtained by wire-explosion spraying by using this wire.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a wire rod for thermal spraying such as wire bombardment spraying and arc thermal spraying.

[Prior Art] Thermal spraying methods that use a thermal spraying wire as a thermal spraying material include wire blast spraying and arc thermal spraying.

Blast spraying is a technique for forming a film on the surface of the material to be sprayed (hereinafter referred to as base material). C), a wire (43) is connected between the electrodes (42) of a device having a switch (SW) and an electrode (42), a large current is passed through the wire (43) in various atmospheres, and the wire is melted and exploded; A film is formed on the base material (41) by the scattered particles.

Piano wire, molybdenum wire, and the like are conventionally known as wire rods used in such wire bomb spraying.

However, since conventional wire rods are essentially made of a single metal (including alloys), the resulting coating layer is inevitably a metal layer of a single composition, and it is not possible to use wire rods of different types. For example, when piano wire and molybdenum wire are alternately beam-sprayed, the coating layer is simply replaced with a laminated film.

In addition, wire rods are generally manufactured by wire drawing, but this manufacturing method limits the composition of the wire rod, making it difficult to control the composition of the thermal sprayed coating to the desired composition, and because the resulting coating is a laminated coating. The composition is non-uniform in the thickness direction.

Similar problems exist with arc spraying.

[Problems to be Solved by the Invention] The present invention was made in view of the problems in conventional thermal spraying technology, and an object of the present invention is to provide a wire rod for thermal spraying that can be coated with a homogeneous composite coating of a desired composition. .

[Means for Solving the Problems] The present invention provides a thermal spraying material in which the radially outer side of a base material capable of being thermally sprayed is coated with an additional material that improves the properties of the coating.

Furthermore, the present invention provides a thermal spraying wire material in which an additional material for improving the properties of the coating is mixed into a matrix of a base material that can be thermally sprayed.

That is, in order to obtain a composite coating, an additional material that improves the properties of the coating is added to the wire for thermal spraying, and then a more microscopically homogeneous composite coating is produced by thermal spraying.

[Function] When the wire rod of the present invention is energized, at least the base material that can be sprayed by wire blasting melts and explodes, and at that time, the additional material that improves the properties of the coating is also accompanied, and the base material becomes ambivalent. A film is formed in which the materials are distributed in the desired proportions. Therefore, a desired homogeneous composite film can be easily obtained.

In addition, even when forming a film with a composition that cannot be drawn or is difficult to draw, the composite wire of the present invention can be used to achieve the desired composition through the process of melting and scattering the composite wire by wire bombing, which is difficult to do in the past. It becomes possible to pass through a film with a composition that was

[Example 2] The above-mentioned wire bomb sprayable material is a material that has electrical conductivity.

Note that it is difficult to uniformly determine the specific value of the electrical conductivity of a material that can be thermally sprayed because it depends on the thermal spraying equipment.

Specific examples of materials that can be sprayed include piano wire and molybdenum wire.

The wire rod of the present invention is composed of the above-mentioned base material capable of being blast sprayed and an additional material that improves the properties of the coating.

Various materials can be selected as the additional material depending on the characteristics of the desired composite film, the type of base material, and the type of base material.

Specifically, high-hardness materials such as metal materials such as chromium and ceramics such as aluminum oxide may be used, thereby achieving wear resistance with high-hardness particles uniformly dispersed in the coating. This makes it possible to form a complex composite film.

Additional materials may also include lubricious materials such as carbon, boron nitride, etc., thereby forming superior composite coatings with low coefficients of friction.

The number of additional materials may be one, or two or more.

The ratio of the base material to the additional material in the wire can be determined according to the desired coating composition, but if the molten particles of the base material are crushed or accompanied by the molten particles of the additional material and are uniformly spread over the base material. The ratio must be such that a film can be formed. Such a ratio depends on the combination of the two materials and their arrangement in the wire - although it is difficult to generalize;
It is necessary that the composite material of the base material and the additional material be electrically conductive.

Regarding the arrangement of both materials in the wire, as shown in FIG. 1, the wire (3) is formed by coating the base material (1) on the outside in the radial direction with the additional material (2), and the wire (3) is schematically shown in FIG. Preferably, the wire rod (13) is formed by mixing the additional material (12) into the continuous phase of the base material (1).

Example 1 A piano wire with a diameter of 0.85 mm was chromium-plated so that the outer diameter was l,0 mm to produce a wire rod as shown in Fig. 1, and it was thermally sprayed 12 times on a disc-shaped base material made of AC8^. A film with a thickness of 60 μm was formed. The chromium plating method may be electroplating or electroless plating, or may be chemical vapor deposition, physical vapor deposition, or the like.

As shown in Figure 3, the equipment used for thermal spraying has a copper electrode (31) and a wire rod (33) of a certain length (I7).
was placed at a constant spraying distance (A) from the base material (34), and thermal spraying was performed.

Thermal spraying conditions are shown in Table 1.

Example 2 A wire rod was prepared by coating the same biminium (Al2O3) as used in Example 1 with a diameter of 0.85 mm,
Thermal spraying was performed 12 times using the apparatus shown in FIG. 3 to form a film of 60 μm.

The AIO coating was obtained by dipping the piano wire in Al2O3 slurry and then drying it.

sect Thermal spraying conditions are shown in Table 1.

Example 3 An I2O3 dispersed aluminum wire having a diameter of 1.3 mIm and the composition shown in Table 2 (manufactured by ALCAN) was used as a wire rod.
Thermal spraying was performed 12 times using the apparatus shown in the figure to form a film of 60 μm.

Thermal spraying conditions are shown in Table 1.

Table 2 Comparative Examples 1 and 2 For comparison, a piano wire wire rod and a molybdenum wire wire rod were thermally sprayed 12 times using the apparatus shown in FIG. 3 to form a coating of 60 μm, respectively.

The injection conditions were the same as in Example 1 except that the voltages were 7.2 kV and 10 kV, respectively.

The films obtained on the male sides 1 to 3 were examined using a microscope equipped with an elemental analyzer (S-800 manufactured by Hitachi, Ltd., EM^X manufactured by Horiba Co., Ltd.)
When the structure was observed using a microstructure, it was confirmed that a homogeneous film was formed on each base material.

The composition of the portion at a depth of .mu.m from the surface of the films obtained on male sides 1 and 2 was analyzed using the electron microscope, and the results are shown in FIGS. 4 and 5.

As a result of analysis based on FIGS. 4 and 5, it was confirmed that the film had the base material-additional material ratio as shown.

[Effects of the Invention] By using the wire of the present invention, a homogeneous composite coating in which the distribution of the additional material in the base material is sufficiently controlled can be obtained by wire bombardment spraying.

Furthermore, materials that cannot be or are difficult to be sprayed alone can be used as additional materials, making it possible to create novel surface properties compared to coatings conventionally obtained by wire bomb spraying.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing one example of the wire rod of the present invention, FIG. 2 is a cross-sectional view schematically showing another example of the wire rod of the present invention, FIG. The figure is a graph showing the elemental analysis results of the film obtained in Example 1, Figure 5 is a graph showing the elemental analysis results of the film obtained in Example 2, and Figure 6 is an example of the wire bomb spraying method. It is an explanatory diagram. (Main symbols in the drawing), (1), <11): Base material (2), (1
2) : Additional material (3) , (13), (33) : Wire piece 1 Diagram 2 times 12 Additional material'') V6 diagram

Claims (1)

[Claims] 1. A wire rod for thermal spraying consisting of a base material that can be thermally sprayed and an additional material that improves the properties of the coating.