JP2002004028A - Thermal spraying method, and sprayed deposit structure formed by the thermal spraying method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the strength of a thermally sprayed deposit. SOLUTION: A wire 2 consisting of a material which is the same as a thermal spraying material or a material which is bonded with the thermal spraying material to form an alloy or a compound is wound around a surface of a coating material 1, and a molten thermal spraying metal is sprayed thereon. The thermally sprayed deposit 5 and the wire 2 are firmly bonded and integrated with each other to improve the strength of the thermally sprayed deposit 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal spraying method capable of improving the strength of a thermal spray coating and a thermal spray coating structure formed by the thermal spraying method.

[0002]

2. Description of the Related Art Thermal spraying is widely used for various components such as mechanical parts such as rolls and gears and recording heads. Thermal spraying refers to a method in which compressed air is sprayed on a molten metal to spray a sprayed metal on the coating material to form a metal coating layer on the surface. FIG. 4 (a)
FIG. 3 is an explanatory view showing a conventional thermal spraying method. By spraying the spray metal from the thermal spray gun 3 on the tubular coating material 1 in this manner, the thermal spray coating 20 can be formed on the surface thereof.
The thermal spray gun 3 has a different structure depending on the type, such as an electric thermal spraying method, a gas thermal spraying method, or a powder thermal spraying method.

[0003] Thermal spraying features metals, composites, glass,
Most solid materials such as wood and plastics can be coated. However, such bonding between the coating material 1 and the thermal spray coating 20 by thermal spraying causes small projections or depressions on the surface of the coating material 1. It is thought to be due to the anchor effect that mechanically adheres. For this reason, it is indispensable to form a rough surface by forming appropriate irregularities on the surface of the coating material by a thermal spraying pretreatment.

[0004] Pretreatment for thermal spraying includes sandblasting,
A grid blast method, a roughing method, a welding method, a molybdenum alloy spraying method, and the like are used according to the purpose of use. In addition, before roughening, a degreasing process and a descaling process are performed. Since the thermal spray coating 20 has a porous layered structure and contains an oxide, the hardness of the thermal spray coating 20 is larger than that of the raw material, and the wear resistance is improved. In order to improve the corrosion resistance, sealing treatment or melting treatment is necessary since the thermal spray coating 20 is porous.

[0005]

However, the thermal spray coating 20 formed by the above general thermal spraying method is weaker than the raw material itself due to oxidation of the thermal spray particles and the like. Further, since the thermal spray coating 20 has a very high thermal spraying temperature, the thermal spray coating 20 contracts due to a decrease in temperature after the coating is formed, and a tensile stress is generated in the thermal spray coating 20. Therefore, as shown in FIG. 4B, there is a risk that the thermal spray coating 20 may be damaged in the circumferential direction (cracks 21), and there is a problem that the thermal spray coating 20 cannot be used in a portion where a large force is applied.

Accordingly, the present invention has been made in view of the above, and has as its object to provide a thermal spraying method capable of improving the strength of a thermal sprayed coating and a thermal sprayed coating structure formed by the thermal spraying method.

[0007]

In order to achieve the above object, a thermal spraying method according to claim 1 comprises a wire rod made of the same material as the thermal spraying material or a material which is combined with the thermal spraying material to form an alloy or a compound; Alternatively, the method includes a step of disposing a net-like body formed by assembling the wire on the surface of the coating material, and a step of forming a thermal spray coating by spraying a molten thermal spray material from above while the wire is disposed. .

[0008] The thermal spray coating structure according to claim 4 is characterized in that:
A wire made of the same material as the sprayed material or a material that forms an alloy or a compound by being combined with the sprayed material, or a net-like body formed by assembling the wire is arranged on the surface of the coating material, and the wire is placed on the wire. It is formed by spraying a molten sprayed material.

When the sprayed material is sprayed from above the wire disposed on the surface of the coating material, the sprayed material is fused with the wire or forms an alloy or a compound with the wire. In the thermal spray coating thus formed, the wire and the thermal spray coating are firmly bonded and integrated to improve the strength. Further, according to the net-like body formed by assembling the wires, the strength of the thermal spray coating is further improved.

[0010] According to a second aspect of the present invention, there is provided a thermal spraying method, comprising: implanting a micro-bar made of the same material as the thermal spray material or a material forming an alloy or a compound by combining with the thermal spray material on a surface of the coating material; Forming a thermal spray coating by spraying a molten thermal spray material from above with the material implanted.

[0011] The thermal spray coating structure according to claim 5 is characterized in that:
A micro-bar made of the same material as the thermal spray material or a material that forms an alloy or a compound by being combined with the thermal spray material was implanted on the surface of the coating material, and was formed by spraying the molten thermal spray material from above the micro-bar. A sprayed coating structure characterized by the above.

[0012] A minute rod is implanted on the surface of the coating material,
When the sprayed material is sprayed thereon, it fuses with the micro-bar or forms an alloy or a compound with the micro-bar. In the thermal spray coating formed in this way, the strength is improved by firmly bonding and integrating the fine rod material and the thermal spray coating.
Further, since the fine rod is implanted in the coating material, the adhesion between the thermal spray coating and the coating material is also improved.

According to a third aspect of the present invention, in the above thermal spraying method, a groove is formed in the coating material, and the wire is arranged along the groove. The thermal spray coating structure according to claim 6 is such that the wires are arranged along grooves formed in the coating material. By arranging a wire along the groove and spraying the thermal spray material from above, the wire is fixed in the groove and the thermal spray material enters the groove.
Thereby, the strength of the thermal spray coating is improved and the adhesion between the thermal spray coating and the coating material is improved.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. The present invention is not limited by the embodiment.

(First Embodiment) FIG. 1 is an explanatory view showing a thermal spraying method according to a first embodiment of the present invention. In this thermal spraying method, first, a wire 2 is wound around the surface of a tubular coating material 1 as shown in FIG. The cross-sectional shape of the wire 2 may be circular or rectangular. The wire 2 is made of the same material as the material to be sprayed, or a material that can be combined with the sprayed material to form an alloy or a compound. In addition,
Before winding the wire 2, predetermined degreasing treatment, descaling treatment, and rough surface treatment according to the purpose are performed.

Next, spray metal 4 is sprayed from the spray gun 3 and spraying is performed with the wire 2 wound on the surface of the coating material 1. As a result, the spray metal is covered on the wire 2, and as shown in FIG. 1 (b), the thermal spray coating 5 and the wire 2 are firmly joined and integrated. Metals, ceramics, cermets, and the like can be used as the thermal spray material. The thermal spraying method is selected and used according to a material to be coated by various known thermal spraying methods. For example, in recent years, advanced surface treatment with ceramics has been increasing, and a plasma jet apparatus is used for thermal spraying of such a high melting point material.

The thermal spray coating 5 thus formed is a normal porous coating similar to the above, but since the wire 2 is embedded in and bonded to the thermal spray coating 5, the strength of the entire thermal spray coating 5 is reduced. improves. For this reason, breakage hardly occurs due to tensile stress caused by cooling shrinkage of the thermal spray coating 5 or thermal stress caused by a difference in thermal expansion coefficient with the coating material 1. In addition, although a roughing method may be used as a normal thermal spraying pretreatment,
Since this method is to machine irregularities by using a lathe, it is not suitable for hard metals and the like. On the contrary,
Since this thermal spraying method only winds the wire 2,
The hardness of the coating material 1 does not matter.

As a specific spray metal, a high melting point metal such as niobium, tantalum or rhenium can be used.
In addition, specific wire rods include the above niobium, tantalum,
A wire of a high melting point metal such as rhenium can be used.

In the first embodiment, the coating material 1
Although the wire 2 is wound around, the net-shaped wire 6 may be wound around the tubular coating material 1 as shown in FIG. 2A, and thermal spraying may be performed from above. Also,
As shown in FIG. 2B, the wires 2 may be double-wound and intersect. In this way, the strength can be improved in all directions on the thermal spray coating 5 surface.
Further, as shown in FIG. 4C, a slightly wide groove 7 for fixing the wire 2 may be formed on the surface of the coating material 1 and the wire 2 may be wound along the groove 7. By doing so, not only the strength of the thermal spray coating 5 but also the adhesion to the coating material 1 are improved.

(Embodiment 2) FIG. 3 is an explanatory view showing a thermal spraying method according to Embodiment 2 of the present invention. In this thermal spraying method, first, as shown in FIG. 1A, a plurality of minute bars 11 are implanted in a flat material 10. Small bar 11
Is implanted by sharpening the tip and press-fitting it, or in the case of a composite material, weaving the fine rod 11 into a composite fabric. For the micro-bar 11, the same material as the material to be sprayed is used, or a material that can be combined with the sprayed material to form an alloy or a compound is used. Before implanting the minute rod material 11, a predetermined degreasing treatment, descaling treatment, and rough surface treatment according to the purpose are performed.

Next, the spray metal 4 is sprayed from the thermal spray gun 3, and thermal spraying is performed in a state where the fine bar 11 is implanted on the surface of the flat material 10. As a result, the micro-bar 11 is buried in the thermal spray coating 12, and as shown in FIG. 3B, the thermal-spray coating 12 and the micro-bar 11 are firmly bonded and integrated. Further, as described above, metal, ceramics, cermet, and the like can be used as the thermal spray material. The thermal spraying method is selected and used according to a material to be coated by various known thermal spraying methods.

The thermal spray coating 12 thus formed is
Although it is an ordinary porous coating similar to the above, the strength of the entire thermal spray coating 12 is improved because the fine rod 11 is embedded in and bonded to the thermal spray coating 12. Further, since the fine rod material 11 is embedded in the flat material 10, the thermal spray coating 12
The adhesion between the plate material 10 and the plate material 10 is also improved. For this reason, breakage is less likely to occur due to tensile stress caused by cooling shrinkage of the thermal spray coating 12 and thermal stress caused by a difference in thermal expansion coefficient with the flat plate material 10, and peeling can be prevented.

As the thermal spray metal and the fine rod 11, those described in the above specific examples are used. In addition, besides the minute bar material 11,
As long as it has a shape that has an anchoring effect on the surface of the plate-shaped material 10, a material such as a thin plate material can be used.

[0024]

As described above, in the thermal spraying method of the present invention (claim 1), a wire made of the same material as the thermal sprayed material or a material which forms an alloy or a compound by being combined with the thermal sprayed material, or this wire is used. The method includes a step of disposing a net-like body formed by assembling on the surface of the coating material, and a step of forming a thermal spray coating by spraying a molten thermal spray material from above while the wire is disposed. Further, in the thermal spray coating structure of the present invention (claim 4), a wire made of the same material as the thermal spray material or a material combined with the thermal spray material to form an alloy or a compound, or a net-like body formed by assembling the wires is used. It was arranged on the surface of the coating material, and was formed by spraying a molten sprayed material over the wire. For this reason, the strength of the thermal spray coating is improved.

In the thermal spraying method according to the present invention (claim 2), a step of implanting a micro-bar made of the same material as the thermal spraying material or a material forming an alloy or a compound by combining with the thermal spraying material is provided on the surface of the coating material. Forming a thermal spray coating by spraying the molten thermal spray material from above with the micro-bars implanted. Further, in the thermal spray coating structure of the present invention (claim 5), a micro-bar made of the same material as the thermal spray material or a material which is combined with the thermal spray material to form an alloy or a compound is implanted on the surface of the coating material. It was formed by spraying a molten sprayed material from above the material. Therefore, the strength of the thermal spray coating is improved and the adhesion between the thermal spray coating and the coating material is improved.

In the thermal spraying method of the present invention (claim 3), a groove is formed in the coating material, and the wire is disposed along the groove. Still further, in the thermal spray coating structure of the present invention (claim 6), the wire is arranged along a groove formed in the coating material. By doing so, the strength of the thermal spray coating is improved and the adhesion between the thermal spray coating and the coating material is improved.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram illustrating a thermal spraying method according to a first embodiment of the present invention;

FIG. 2 is an explanatory view showing a modification of the thermal spraying method shown in FIG.

FIG. 3 is an explanatory view showing a thermal spraying method according to a second embodiment of the present invention.

FIG. 4 is an explanatory view showing a conventional thermal spraying method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Coating material 2 Wire rod 3 Thermal spray gun 4 Spray metal 5 Thermal spray coating

Claims (6)

[Claims] A step of disposing a wire made of the same material as the sprayed material or a material forming an alloy or a compound by being combined with the sprayed material, or a net-like body formed by assembling the wires, on a surface of the coating material; Forming a thermal spray coating by spraying a molten thermal spray material from above on a wire disposed thereon. 2. A step of implanting a micro-bar made of the same material as the thermal spray material or a material which forms an alloy or a compound by being combined with the thermal spray material on the surface of the coating material; Spraying the molten thermal spray material to form a thermal spray coating. 3. The thermal spraying method according to claim 1, further comprising forming a groove in the coating material, and arranging the wire along the groove. 4. A wire made of the same material as the sprayed material or a material which forms an alloy or a compound by being combined with the sprayed material, or a net-like body formed by assembling the wires, is arranged on the surface of the coating material, A sprayed coating structure formed by spraying a molten sprayed material from above the wire. 5. A micro-bar made of the same material as the thermal spray material or a material which is combined with the thermal spray material to form an alloy or a compound is implanted on the surface of the coating material, and the molten thermal spray material is sprayed on the micro-bar. A sprayed coating structure characterized by being formed by performing 6. The thermal spray coating structure according to claim 4, wherein said wire is further arranged along a groove formed in said coating material.