JPS59133360A - Melt-spraying material - Google Patents

Abstract

PURPOSE:To obtain a spraying material capable of giving a coating with superior adhesive strength and superior resistance to wear, seizure, wear at high temp. and corrosion by using a mixture having a specified composition consisting of Cu or Cu alloy powder and BN powder coated with Cu. CONSTITUTION:This spraying material is made of a mixture consisting of Cu or Cu alloy powder and 5-70vol.% BN powder coated with Cu. The spraying material gives a sprayed layer with high adhesive strength, and the sprayed layer has no compatibility with a metallic member on which the layer is formed and does not react with the metallic member, so the characteristics of the spraying material can be retained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention coats the surface of a processed VIJ plate with a material different from the composition of the workpiece by a thermal spraying method to improve wear resistance, burn resistance,
*'t1. Resistance to cold weather, corrosion resistance, etc. ``F7'' relates to a thermal spray material that provides a single layer.

Thermal spraying is one method of imparting a texture different from the base material to the surface of counterfeit products and machinery. This is a material that has the required properties by melting it with a chemical combustion flame such as a total oxygen-acetelene or oxygen-hydrogen flame, or with electrical energy such as an electric arc or plasma jet, and then spraying it as fine particles in the form of a strainer spray to coat it. It forms a layer. As this sprayed layer, a material that enhances rust prevention, corrosion prevention, abrasion resistance, extreme heat resistance, etc. is used. In general, coatings formed by thermal spraying are rapidly solidified during thermal spraying, resulting in properties that are markedly different from melted materials with the same components. Even with the same composition, thermally sprayed material has higher hardness than molten material. Furthermore, since pores exist in the sprayed layer, it can provide lubricity and generally improve wear resistance. In particular, thermal spraying materials for imparting severe abrasion resistance include steel, iron-proofing, aluminum-silicon thread alloy, copper-based alloy,
Self-fusing assemblies, cemented carbide, ceramics, and titanium alloys are used, and these materials are used depending on operating conditions or friction conditions. First of all, since this thermal spray layer is made of steel, some of it becomes martensite due to thermal spraying, so it becomes hard and has high wear resistance. However, since M is brittle and has low seizure resistance, there is a limit to its application to members with improved wear resistance. Self-fusing alloys are made by adding boron and silicon to nickel or cobalt-based alloys to create a eutectic alloy, and they also have a 7-six action, and after thermal spraying, the coating is heated above its melting point, so it is made of materials with high adhesion. Ru. This coating has various hard intermetallic compounds, so it has high wear resistance, but the coating is brittle due to the action of boron, and there are problems in terms of galling resistance and compatibility with the mating material on the sliding surface. . Cemented carbide with high wear resistance and Sesimink material are generally high melting point materials, so coating is performed by plasma spraying. This coating is extremely hard and has high abrasion resistance, so it is widely used in mechanical seals and sliding parts of molds. However, although this coating has high wear resistance, it has the disadvantage that it is hard and brittle and requires a long time to finish, so it is limited to special uses. Coatings made of aluminum and copper alloys are soft and have good conformability on sliding surfaces due to partial laminar flow, and are also tough and easy to finish, so they are sometimes used on friction surfaces. There are problems in terms of abrasion resistance and seizure resistance, especially in areas where 2''L'i occurs.

Nitriding for seizure resistance or wear resistance at high temperatures
The cable immediately shows the characteristics of t'. However, when viewed as a thermal spray material, boron nitride generally sublimates without melting at atmospheric pressure. Therefore, even if it is mixed with various powders and thermally sprayed, the adhesion force is extremely low.

The purpose of the present invention is to provide a thermal spray material that has high adhesion and does not damage the properties of substances different from the composition of the component, and a method for producing the same. It is on offer.

Another object of the present invention is to provide a thermal spray material for obtaining a sliding member with high wear resistance without impairing the conformability and flexibility of copper or copper alloy.

In the thermal spraying material of the present invention, which is fixed to the surface of a metal member by full thermal spraying of a substance different from the composition of the member, the substance is characterized in that: 1) the substance is coated with a metal that is incompatible with the substance; It is something to do. According to the present invention, a thermally sprayed layer with high adhesion can be obtained, and since the coating material does not react with a substance having a composition different from that of the member, the properties of the substance can be utilized as is. Therefore, the properties of the material can be selected to be the best as required for the thermal spray layer. In the present invention, the term "the substance and the coating metal are incompatible" means that they do not form a compound or form an alloy near the melting temperature of the lower one of the two substances. Examples of this include aluminum, nitrogen, and boron.

The metal coating surrounds a substance that has a different composition from the metal member, and by thermal spraying, the coating metal is coated on the surface of the metal member.
Since C alloys with the coating metals, a sprayed layer with high adhesion can be formed. Therefore, the material must be selected so that the coating metal does not react with the substance during thermal spraying. Furthermore, in order to increase adhesion, it is better to use the same metal as the main component of the material.

The thermal spray material of the present invention is made of copper or steel alloy powder and boron nitride coated on steel.

According to the present invention, it is possible to uniformly disperse the nitrided coating in the thermal sprayed layer, and to obtain a thermal sprayed layer metal with high adhesion, excellent wear resistance, yield strength and stiffness, and self-lubricating properties.

The method for producing a thermal spray material of the present invention is characterized in that a powder of a substance different from the composition of the member is fixed on the surface of a metal member by thermal spraying, and the material is coated with a metal that is incompatible with the substance by chemical plating. That is. covered &
By chemical plating, it is possible to drive out the gas adsorbed on the surface of the substance, and at the same time, it melts only the plating in the thermal spray flame and prevents decomposition of the boron nitride, so the adhesion is further improved by thermal spraying. Furthermore, a thermal sprayed layer without pores can be obtained. That is, the inventors of the present application have found that if dregs are adsorbed in the substance, the adsorbed gas expands during thermal spraying, which causes pores to be formed in the thermally sprayed layer.

In order to form a strong and dense layer of copper-coated boron nitride on the surface of the material to be thermally sprayed, at least a part of the copper-covered surface of the thermal spray particles is melted in a heat source and scattered onto the surface of the material to be thermally sprayed, and the resulting kinetic energy is used to flatten the particles. , we need to do more than expand. Boron nitride burns when mixed with oxygen and does not form a solid solution with the base material copper-based alloy. Therefore, when nitriding powder is mechanically mixed into the copper-based alloy and sprayed, the nitriding wire is formed on the surface of the material to be thermally sprayed. is scattered and hardly any remains in the film. -i near c including 2''L'fc Even in the field, the nitriding element will inevitably adhere while burning with the oxygen gas that mixes into the thermal spray heat source from the atmosphere, so there should be a gap between the wall and the copper alloy base. This makes the film extremely fragile and unsuitable as a sliding material.

Generally, in order to be used as a sliding member, a certain degree of fart strength or compressive strength is required. The inventors used nitrided copper thread alloy on the surface of the cable, and copper and copper-based alloys with limited solid solubility? It was revealed that by chemical plating, mixing, and thermal spraying, it is possible to firmly adhere to the thermal spray layer. As the material for chemical plating, it is preferable to use a material that is metallically bonded to the base copper-based alloy by mercury or eutectic, and a material that has a hardness close to that of the base material. Copper-based materials are particularly suitable for this material. The particle size of steel coating nitride is 1 to 100 μm as it does not affect the workability of thermal spraying or the uniformity of the coating.
is good, preferably 5 to 50 Atm. During chemical plating, particles with a diameter of 5 μm or more are preferable in order to prevent them from floating in the plating solution and to form plating with a uniform thickness on the surface of each particle. When boron nitride plated with a copper-based alloy layer is thermally sprayed, the metal part on the surface melts and reacts with the base to form a strong bond, leaving the boron nitride particles as they were with almost no flattening. On the other hand, the base copper alloy is melted and sprayed.
Because of this, the surface to be thermally sprayed is largely flattened. Therefore, the grain size of the steel-coated boron nitride is preferably 100 μm or less in order to form a dense sprayed layer. The thickness of the plating film is preferably 1 to 70 μm, preferably 5 to 20 μm.

That is, the thickness is preferably 1 μm or more in order to prevent the molten copper plating film from moving vertically due to surface tension during thermal spraying, exposing a portion of the boron nitride and causing a loss of adhesion.

From the viewpoint of securing the necessary amount of boron nitride and wear resistance, the thickness is preferably 30 μm or less. For wear resistance and sliding parts, the amount of boron nitride coated with copper is preferably 5 to 70 inches for each ridge. Deterioration of wear resistance - 5 ways to prevent it completely
The higher the amount of boron nitride, the better the wear resistance and anti-seizure properties will be.However, since it saturates at about 50%, it is better to use less than 50% to obtain a coating with high adhesion. In addition, when dispersing and casting copper-coated boron nitride powder, which is chemically plated on copper or copper-based alloys, on the surface of boron nitride, copper-coated boron nitride decomposes or burns when oxygen is mixed in, so Very little remains. It has been revealed that by thermal spraying a mixture of copper and copper-based alloys with copper-coated boron nitride, it is possible to achieve strong adhesion in the thermal sprayed layer.

Example 1 Copper-based alloy powder (aluminum 11% by weight - balance copper and 1% by weight)
Boron nitride powder with a thickness of 5 to 30 μm is coated with copper to a thickness of 5 μm using an electroless chemical plating method.
The powder obtained by mixing 0, 30, 40, 50, 60° and 70% was subjected to oxygen-acetylene, oxygen-hydrogen method and plasma method (4
00A (7) Ar, diameter 2 from N2 Frisma>itc
Thermal spraying was carried out on the end face of a 5cm round bar and on the mild steel surface of 30m+80m and 7m. The surface to be thermally sprayed was roughened by grid plasting, and then preheated to 150'c. Spraying thickness is approximately 0.7
It's a crow.

FIG. 1 is a diagram showing the results of measuring the adhesion of a thermally sprayed layer of boron nitride coated with copper plating. Adhesion strength decreases as the amount of copper-coated boron nitride increases, but
Approximately 120 kg/ even when the amount of copper-coated boron nitride is 50%
It shows a high value of cm2.

Comparative Example 1 As in Example 1, a mixture of copper-based alloy powder and boron nitride without plating was mixed with boron nitride amounts of 20.40 and 70 vol.
% was subjected to 7 rhythm baths, but in all cases the boron nitride powder was oxidized and almost disappeared, and no boron nitride was observed.

Comparative Example 2 Copper-based alloy powder (11% by weight of aluminum - balance copper) of 37 to 78 μm and nickel of 10 to 50 μm (7) boron nitride powder set to a thickness of 5 μm by electroless plating, 5 .10.20.30,4050.6
The powder obtained by mixing 0.70% was subjected to oxygen-acetylene, oxygen-hydrogen method, and plasma method (400A).

A 11 N 2 plasma) was used to thermally spray the end face of a round bar with a diameter of 25 mm and the surface of mild steel with a diameter of 30 trm, 80 rrrm, and 7 mm.

After the surface to be thermally sprayed is roughened by grid plasting,
15 (I' preheated. The spraying thickness is about 0.7 cm.

Figure 2 shows the JIS standard 0 thermal sprayed layer that was thermally sprayed on mild steel plates in Example 1 and Comparative Example 1.2 by machining and lapping.
．． 5S is a diagram showing the results of all abrasion resistance tests carried out using the large-scale abrasion test method. A1 and 2 are the products of the present invention produced in Example 1, Ya 3 is the one produced in Comparative Example 2, and Ani 4 is the one produced in Comparative Example 1 without a styling coating. JFil, 3 and 4 have a friction speed of 20m
/sec and A2 is the friction velocity of 0.6 m/sec. The mating material for the wear test was JIS standard 5UJ2 bearing steel (
The hardness is 760 to 850 Hv). Friction distance is 200
m, the load was 18.9 kg, and the lubricant was turbine oil.

As shown in the figure, the wear resistance of steel coated with the thermal spraying material of the present invention increases significantly as the amount of boron in the steel coating increases. In particular, it can be seen that the abrasion resistance of the copper-based alloy powder mixed with copper-plated boron nitride (A1) is significantly superior to that of the mixture of nickel-plated boron nitride (A3).

However, in the case of the material not coated with plating (No. 4), almost no boron nitride remains in the sprayed layer, and therefore, when the total amount of boron nitride in the sprayed material is increased, the wear resistance tends to decrease.

As mentioned above, the reason why the sprayed layer obtained using the sprayed material of the present invention has excellent wear resistance is due to the fact that it contains boron nitride, but it is also due to its high adhesion. I lie even thinking that.

FIG. 3 is a 100 times magnified micrograph of a thermally sprayed layer produced in a fill'''C case with a boron nitride amount of 40.lambda.

The sprayed layer has no pores and is formed as a dense layer on the material to be sprayed.

As described above, the thermal spraying material used on the thermal spraying material of the present invention has a significantly large dense layer force, and the thermal spraying layer obtained as a sliding part using a mixture of copper-based alloy and copper-coated boron nitride has the characteristics of boron nitride. Highly wear resistant and extremely wear resistant.
c effect was exerted.

[Brief explanation of the drawing]

Figure 1 is a diagram showing the relationship between the adhesion of a thermally sprayed layer using plating-coated boron nitride and the amount of boron nitride, Figure 2 is a diagram showing the relationship between specific wear amount and boron nitride, FIG. 3 is a photomicrograph of a thermally sprayed layer using all of the thermally sprayed materials of the present invention. ~32・% 1 Figure' f5101 Manufactured by Hitachi Co., Ltd. Address: 5-5-1, Marunouchi-chome, Chiyoda-ku, Tokyo, Japan (100) The column for a brief explanation of the drawings in the specification subject to the amendment is based on the popular shooting material of Fuenimon. "It is a clear challenge and truth of the popular people who used it for convenience" is corrected to "It is a diagram that shows." 325

Claims (1)

[Claims] 1. In the method of forming a coating on the ice surface of a metal member by thermal spraying a powder of a substance different from the composition of the member, copper-i: or a 5-70 coat coated with copper alloy powder and copper. A thermal spray material characterized in that it consists of a mixture of aqueous boron powders. 2. The thermal spray material according to claim 1, wherein the steel-coated boron nitride powder has a particle size of 1 to 100 μIn. 3. The thermal spray material according to claim 1 or 2, wherein the thickness of the steel coating is 1 to 70 μm.