阅读说明：本技术 一种钨铜合金材料用涂层及其制备方法 (Coating for tungsten-copper alloy material and preparation method thereof ) 是由 高卡 孙德建 刘东岳 马天宇 赵峻良 马鑫藤 高阳 程俊伟 郭晓琴 张锐 于 2020-12-11 设计创作，主要内容包括：本发明公开了一种钨铜合金材料用涂层,所述涂层包括在合金材料表面依次形成的过渡层和抗氧化层,过渡层包括以下重量份的原料：纳米氧化锡15-20份、氟化锶10-15份、钛酸四丁酯0.1-0.5份、聚乙烯醇1-5份；所述抗氧化层包括以下重量份的原料：纳米氧化铈10-20份、硅钡铁合金粉30-50份。过渡层添加纳米氧化锡和氟化锶两种成分,提高过渡层的结合强度,降低孔隙率。抗氧化层中的硅钡铁合金粉在高温环境下和氧气反应,避免合金材料在高温下被氧化,纳米氧化铈提高抗氧化层的致密性。本发明还提供了一种钨铜合金材料用涂层的制备方法,过渡层采用烧结的方式制备,抗氧化层采用超音速火焰喷涂在过渡层表面,保证涂层在合金材料表面分布均匀,不易开裂脱落。(The invention discloses a coating for a tungsten-copper alloy material, which comprises a transition layer and an anti-oxidation layer which are sequentially formed on the surface of the alloy material, wherein the transition layer comprises the following raw materials in parts by weight: 15-20 parts of nano tin oxide, 10-15 parts of strontium fluoride, 0.1-0.5 part of tetrabutyl titanate and 1-5 parts of polyvinyl alcohol; the anti-oxidation layer comprises the following raw materials in parts by weight: 10-20 parts of nano cerium oxide and 30-50 parts of silicon barium iron alloy powder. The transition layer is added with two components of nano tin oxide and strontium fluoride, so that the bonding strength of the transition layer is improved, and the porosity is reduced. The silicon-barium-iron alloy powder in the anti-oxidation layer reacts with oxygen in a high-temperature environment, so that the alloy material is prevented from being oxidized at high temperature, and the nano cerium oxide improves the compactness of the anti-oxidation layer. The invention also provides a preparation method of the coating for the tungsten-copper alloy material, the transition layer is prepared in a sintering mode, and the antioxidation layer is sprayed on the surface of the transition layer by adopting supersonic flame, so that the coating is uniformly distributed on the surface of the alloy material and is not easy to crack and fall off.)

1. The coating for the tungsten-copper alloy material is characterized by comprising a transition layer and an anti-oxidation layer which are sequentially formed on the surface of the alloy material, wherein the transition layer comprises the following raw materials in parts by weight: 15-20 parts of nano tin oxide, 10-15 parts of strontium fluoride, 0.1-0.5 part of tetrabutyl titanate and 1-5 parts of polyvinyl alcohol; the anti-oxidation layer comprises the following raw materials in parts by weight: 10-20 parts of nano cerium oxide and 30-50 parts of silicon barium iron alloy powder.

2. The coating as claimed in claim 1, wherein the thickness of the transition layer is 30-50 μm, and the thickness of the oxidation-resistant layer is 100-200 μm.

3. The coating for the tungsten-copper alloy material according to claim 1, wherein the mass fraction of tungsten in the tungsten-copper alloy material is 90%, and the mass fraction of copper in the tungsten-copper alloy material is 10%.

4. A method for preparing a coating for a tungsten-copper alloy material according to claims 1 to 3, comprising the steps of:

(1) pretreating the surface of the tungsten-copper alloy material;

(2) adding nano tin oxide and strontium fluoride into absolute ethyl alcohol, adding tetrabutyl titanate and polyvinyl alcohol, and uniformly mixing to prepare slurry;

(3) spraying the slurry prepared in the step (2) on the surface of the tungsten-copper alloy material, and pre-curing at the temperature of 100-150 ℃;

(4) sintering the material pre-cured in the step (3) to obtain a transition layer;

(5) and ball-milling and mixing the nano cerium oxide and the silicon-barium-iron alloy powder, and spraying the mixture on the surface of the transition layer by adopting supersonic flame to obtain the anti-oxidation layer.

5. The method as claimed in claim 4, wherein the sintering conditions in the step (4) are sintering at 300-400 ℃ for 1-2h under the protection of argon atmosphere, and heating to 900-1000 ℃ for 1-2 h.

6. The preparation method of the coating for the tungsten-copper alloy material, according to claim 4, characterized in that the specific conditions of the supersonic flame spraying in the step (5) are as follows: the spraying distance is 220-250mm, the powder feeding speed is 20-30g/min, the kerosene flow is 20-25L/h, the oxygen flow is 800-850L/min, and the pressure in the combustion chamber is 2.0-2.5 MPa.

7. The method for preparing the coating for the tungsten-copper alloy material, according to claim 4, wherein the volume of the absolute ethyl alcohol is 2-3 times of the total volume of the nano tin oxide and the nano strontium fluoride.

8. The method for preparing the coating for the tungsten-copper alloy material according to claim 4, wherein the surface of the material is pretreated by using a diamond grinder in the step (1).

Technical Field

The invention relates to a coating, in particular to a coating for a tungsten-copper alloy material and a preparation method thereof.

Background

The tungsten alloy is an alloy which is based on tungsten (the tungsten content is 85-99%) and is added with a small amount of Ni, Cu, Fe, Co, Mo, Cr and other elements, and has the advantages of high density, high melting point, large specific gravity and good electric and heat conduction performance, and the density of the alloy is as high as 16.5-18.75g/cm³Commonly known as high gravity alloys, heavy alloys or high density tungsten alloys. The tungsten-copper alloy is widely used in the industries of aerospace, electronics, weapon manufacturing and the like, and is commonly used for manufacturing gyroscope rotors, armor piercing bullet cores, heat shields, electrodes and the like. However, tungsten-copper alloys are easily oxidized in a high-temperature aerobic environment and are relatively rapidly oxidized at temperatures of 400 ℃ or higher to form oxides that are not protective (WO)₃) And the excellent high-temperature resistance of the alloy is lost, the tungsten-copper-based alloy is difficult to use in the environment with the temperature of more than 1500 ℃, and the use of the tungsten-copper-based alloy in extreme environment is limited. In order to improve the high-temperature oxidation resistance of the tungsten-copper alloy, a popular method at present is to prepare a high-temperature oxidation resistant coating on the surface of the tungsten-copper alloy.

The existing coating on the surface of the tungsten-copper alloy material has a plurality of problems, can not meet the application requirements of the alloy material in different fields, such as loose combination with the material surface, easy falling off, high porosity, poor compactness, incapability of meeting the use requirement due to oxidation resistance and the like, and limits the application of the tungsten-copper alloy, so that a coating is urgently needed to solve the problems.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention aims to provide the coating for the tungsten-copper alloy material, which has the advantages of high bonding degree with the alloy material, difficult falling, low porosity and better high-temperature oxidation resistance.

The second purpose of the invention is to provide a preparation method of the coating for the tungsten-copper alloy material.

One of the purposes of the invention is realized by adopting the following technical scheme:

the coating for the tungsten-copper alloy material comprises a transition layer and an anti-oxidation layer which are sequentially formed on the surface of the alloy material, wherein the transition layer comprises the following raw materials in parts by weight: 15-20 parts of nano tin oxide, 10-15 parts of strontium fluoride, 0.1-0.5 part of tetrabutyl titanate and 1-5 parts of polyvinyl alcohol; the anti-oxidation layer comprises the following raw materials in parts by weight: 10-20 parts of nano cerium oxide and 30-50 parts of silicon barium iron alloy powder.

Further, the thickness of the transition layer is 30-50 μm, and the thickness of the oxidation resistant layer is 100-200 μm.

Further, the mass fraction of tungsten in the tungsten-copper alloy material is 90%, and the mass fraction of copper is 10%.

The second purpose of the invention is realized by adopting the following technical scheme:

the preparation method of the coating for the tungsten-copper alloy material comprises the following steps:

(1) pretreating the surface of the tungsten-copper alloy material;

(2) adding nano tin oxide and strontium fluoride into absolute ethyl alcohol, adding tetrabutyl titanate and polyvinyl alcohol, and uniformly mixing to prepare slurry;

(3) spraying the slurry prepared in the step (2) on the surface of the tungsten-copper alloy material, and pre-curing at the temperature of 100-150 ℃;

(4) sintering the material pre-cured in the step (3) to obtain a transition layer;

(5) and ball-milling and mixing the nano cerium oxide and the silicon-barium-iron alloy powder, and spraying the mixture on the surface of the transition layer by adopting supersonic flame to obtain the anti-oxidation layer.

Further, the sintering condition in the step (4) is sintering at 400 ℃ for 1-2h under the protection of argon atmosphere and at the temperature of 900 ℃ to 1000 ℃ for 1-2 h.

Further, the specific conditions of the supersonic flame spraying in the step (5) are as follows: the spraying distance is 220-250mm, the powder feeding speed is 20-30g/min, the kerosene flow is 20-25L/h, the oxygen flow is 800-850L/min, and the pressure in the combustion chamber is 2.0-2.5 MPa.

Further, the volume of the absolute ethyl alcohol is 2-3 times of the total volume of the nano tin oxide and the strontium fluoride.

Further, in the step (1), a diamond grinding machine is adopted to pretreat the surface of the material.

Compared with the prior art, the invention has the beneficial effects that:

1. the invention provides a coating for a tungsten-copper alloy material, which comprises a transition layer and an oxidation resistant layer which are sequentially arranged on the surface of the material, wherein the transition layer is added with two components of nano tin oxide and strontium fluoride, the nano tin oxide has better toughness, the nano metal tin oxide is more easily distributed on the surface of the alloy material uniformly, the bonding strength of the transition layer is improved, and the porosity is reduced. The strontium fluoride has certain fluidity at high temperature, and the transition layer forms a fluidity film layer with better toughness on the surface of the material under the high-temperature environment, and the fluidity film layer is used as an oxidation resistant layer and a transition layer of an alloy material, so that the durability of the coating is improved, the coating is prevented from cracking, the film layer can also be used as a protective film to repair cracks on the surface of the alloy material, further diffusion of air in an alloy matrix is prevented, and the oxidation resistance effect of the coating at high temperature is improved. In the preparation process of the transition layer, absolute ethyl alcohol is added as a carrier, tetrabutyl titanate is used as a catalyst, polyvinyl alcohol is used as a binder, the mixture is sprayed on the surface of a tungsten-copper alloy material, and the transition layer is obtained by high-temperature sintering and is used as a transition layer between an oxidation resistant layer and the alloy material, so that the bonding is firm.

2. The anti-oxidation layer takes the nano cerium oxide and the silicon-barium-iron alloy powder as raw materials, the silicon-barium-iron alloy powder can react with oxygen in a high-temperature environment, the alloy material is prevented from being oxidized at high temperature, the nano cerium oxide has small particle size, large specific surface area and very strong surface activity, the compactness of the anti-oxidation layer is improved when the nano cerium oxide is used in the anti-oxidation layer, the oxygen in the air is further prevented from contacting with the surface of the alloy material, the raw materials of the anti-oxidation layer are uniformly distributed on the transition layer under the supersonic flame spraying effect, and are fused with the surface part of the transition layer close to the anti-oxidation layer to form a fusion layer, the combination is firm, and the anti-oxidation layer.

3. The invention also provides a preparation method of the coating for the tungsten-copper alloy material, the transition layer is prepared in a sintering mode, and the antioxidation layer is sprayed on the surface of the transition layer by adopting supersonic flame, so that the coating is uniformly distributed on the surface of the alloy material and is not easy to crack and fall off.

Drawings

FIG. 1 is a schematic cross-sectional view of a tungsten alloy material surface coated with a coating of the present invention;

in the figure: 1. a tungsten alloy material; 2. a transition layer; 3. anti-oxidation layer, 4, fusion layer.

Detailed Description

The present invention will be further described with reference to the accompanying drawings and the detailed description, and it should be noted that any combination of the embodiments or technical features described below can be used to form a new embodiment without conflict.

Example 1

A coating for a tungsten-copper alloy material (the mass fraction of tungsten in the tungsten-copper alloy material is 90%, the mass fraction of copper is 10%), the coating comprises a transition layer and an anti-oxidation layer which are sequentially formed on the surface of the alloy material, and the transition layer comprises the following raw materials in parts by weight: 15 parts of nano tin oxide, 10 parts of strontium fluoride, 0.1 part of tetrabutyl titanate and 1 part of polyvinyl alcohol; the anti-oxidation layer comprises the following raw materials in parts by weight: 10 parts of nano cerium oxide and 30 parts of silicon-barium-iron alloy powder.

The preparation method of the coating for the tungsten-copper alloy material comprises the following steps:

(1) pretreating the surface of the tungsten-copper alloy material by adopting a diamond grinding machine to remove an oxide layer on the surface of the material;

(2) adding nano tin oxide and strontium fluoride into absolute ethyl alcohol, wherein the volume of the absolute ethyl alcohol is 2 times of the total volume of the nano tin oxide and the strontium fluoride, adding tetrabutyl titanate and polyvinyl alcohol, and uniformly mixing to prepare slurry;

(3) spraying the slurry prepared in the step (2) on the surface of a tungsten-copper alloy material, and pre-curing at the temperature of 100 ℃;

(4) sintering the material pre-cured in the step (3) for 2h at 300 ℃ under the protection of argon atmosphere, heating to 900 ℃ and sintering for 2h to obtain a transition layer with the thickness of about 30 mu m;

(5) ball-milling and mixing the nano cerium oxide and the silicon-barium-iron alloy powder, and then spraying the mixture on the surface of the transition layer by adopting supersonic flame, wherein the specific conditions of the supersonic flame spraying are as follows: the spraying distance is 220mm, the powder feeding speed is 20g/min, the kerosene flow is 20L/h, the oxygen flow is 800L/min, and the pressure of the combustion chamber is 2.0Mpa, so that the antioxidation layer is obtained, the thickness is about 100 mu m, and the antioxidation layer and the transition layer are partially fused to form a fusion layer. The cross-sectional view of the tungsten alloy material after coating is shown in fig. 1.

Example 2

A coating for a tungsten-copper alloy material (the mass fraction of tungsten in the tungsten-copper alloy material is 90%, the mass fraction of copper is 10%), the coating comprises a transition layer and an anti-oxidation layer which are sequentially formed on the surface of the alloy material, and the transition layer comprises the following raw materials in parts by weight: 18 parts of nano tin oxide, 12 parts of strontium fluoride, 0.3 part of tetrabutyl titanate and 2 parts of polyvinyl alcohol; the anti-oxidation layer comprises the following raw materials in parts by weight: 15 parts of nano cerium oxide and 40 parts of silicon barium iron alloy powder.

The preparation method of the coating for the tungsten-copper alloy material comprises the following steps:

(1) pretreating the surface of the tungsten-copper alloy material by adopting a diamond grinding machine to remove an oxide layer on the surface of the material;

(2) adding nano tin oxide and strontium fluoride into absolute ethyl alcohol, wherein the volume of the absolute ethyl alcohol is 2.5 times of the total volume of the nano tin oxide and the strontium fluoride, adding tetrabutyl titanate and polyvinyl alcohol, and uniformly mixing to prepare slurry;

(3) spraying the slurry prepared in the step (2) on the surface of a tungsten-copper alloy material, and pre-curing at the temperature of 120 ℃;

(4) sintering the material pre-cured in the step (3) for 1.5h at 350 ℃ under the protection of argon atmosphere, heating to 950 ℃ and sintering for 1.5h to obtain a transition layer, wherein the thickness of the transition layer is about 40 mu m;

(5) ball-milling and mixing the nano cerium oxide and the silicon-barium-iron alloy powder, and then spraying the mixture on the surface of the transition layer by adopting supersonic flame, wherein the specific conditions of the supersonic flame spraying are as follows: the spraying distance is 240mm, the powder feeding speed is 25g/min, the kerosene flow is 23L/h, the oxygen flow is 830L/min, and the pressure of the combustion chamber is 2.2MPa, so that the antioxidation layer is obtained, the thickness of the antioxidation layer is about 150 mu m, and the antioxidation layer and the transition layer are partially fused to form a fusion layer.

Example 3

A coating for a tungsten-copper alloy material (the mass fraction of tungsten in the tungsten-copper alloy material is 90%, the mass fraction of copper is 10%), the coating comprises a transition layer and an anti-oxidation layer which are sequentially formed on the surface of the alloy material, and the transition layer comprises the following raw materials in parts by weight: 20 parts of nano tin oxide, 15 parts of strontium fluoride, 0.5 part of tetrabutyl titanate and 5 parts of polyvinyl alcohol; the anti-oxidation layer comprises the following raw materials in parts by weight: 20 parts of nano cerium oxide and 50 parts of silicon-barium-iron alloy powder.

The preparation method of the coating for the tungsten-copper alloy material comprises the following steps:

(1) pretreating the surface of the tungsten-copper alloy material by adopting a diamond grinding machine to remove an oxide layer on the surface of the material;

(2) adding nano tin oxide and strontium fluoride into absolute ethyl alcohol, wherein the volume of the absolute ethyl alcohol is 3 times of the total volume of the nano tin oxide and the strontium fluoride, adding tetrabutyl titanate and polyvinyl alcohol, and uniformly mixing to prepare slurry;

(3) spraying the slurry prepared in the step (2) on the surface of a tungsten-copper alloy material, and pre-curing at the temperature of 150 ℃;

(4) sintering the material pre-cured in the step (3) for 1h at 400 ℃ under the protection of argon atmosphere, heating to 1000 ℃ and sintering for 1h to obtain a transition layer, wherein the thickness of the transition layer is about 50 mu m;

(5) ball-milling and mixing the nano cerium oxide and the silicon-barium-iron alloy powder, and then spraying the mixture on the surface of the transition layer by adopting supersonic flame, wherein the specific conditions of the supersonic flame spraying are as follows: the spraying distance is 250mm, the powder feeding speed is 30g/min, the kerosene flow is 25L/h, the oxygen flow is 850L/min, and the pressure of the combustion chamber is 2.5Mpa, so that the antioxidation layer is obtained, the thickness of the antioxidation layer is about 200 mu m, and the antioxidation layer and the transition layer are partially fused to form a fusion layer.

Comparative example 1

Comparative example 1 provides a coating for a tungsten copper alloy material, which is different from example 1 in that: the strontium fluoride in the transition layer was omitted and the same as in example 1 was repeated.

Comparative example 2

Comparative example 2 provides a coating for a tungsten copper alloy material, which is different from example 1 in that: the nano tin oxide in the transition layer was omitted and the rest was the same as in example 1.

Comparative example 3

Comparative example 3 provides a coating for a tungsten copper alloy material, which is different from example 1 in that: the strontium fluoride in the transition layer was replaced with sodium fluoride, and the rest was the same as in example 1.

Comparative example 4

Comparative example 4 provides a coating for a tungsten copper alloy material, which is different from example 1 in that: the strontium fluoride in the transition layer was replaced with strontium metal, and the rest was the same as in example 1.

Comparative example 5

Comparative example 5 provides a coating for a tungsten copper alloy material, which is different from example 1 in that: the transition layer was omitted and the same as in example 1 was repeated.

Comparative example 6

Comparative example 6 provides a coating for a tungsten copper alloy material, which is different from example 1 in that: the nano-ceria in the antioxidation layer was omitted and the rest was the same as in example 1.

The porosity of the coatings prepared in example 1 and comparative examples 1 to 6 was measured by mercury intrusion method, the bonding strength of the coatings was measured according to GB/T8642-.

TABLE 1

As can be seen from Table 1, the coating of example 1 has low porosity, high bonding strength, good high temperature resistance and better oxidation resistance in high temperature environment.

The compositions of the transition layers are adjusted or the transition layers are omitted in comparative examples 1 to 5, strontium fluoride or nano tin oxide is omitted in comparative examples 1 to 2 respectively, strontium fluoride is replaced by sodium fluoride or metal strontium fluoride in comparative examples 3 to 4, the transition layer is omitted in comparative example 5, the porosity of the prepared coating is increased, the binding force is reduced, and the high-temperature resistance is poor, so that the coating provided by the invention is known to have better toughness by arranging the transition layer between the antioxidation layer and the alloy material and selectively adding two components of nano tin oxide and strontium fluoride, the nano tin oxide is more easily and uniformly distributed on the surface of the alloy material by adopting the nano tin oxide, the binding strength of the transition layer is improved, the porosity is reduced, the strontium fluoride has certain fluidity at high temperature, and the transition layer forms a fluidity film layer with better toughness on the surface of the material to be used as the transition layer of the antioxidation layer and the alloy material in a high-temperature environment, the coating has the advantages of improving the durability of the coating, preventing the coating from cracking, repairing cracks on the surface of the material as a protective film, preventing air from further diffusing in a matrix and improving the anti-oxidation effect of the coating at high temperature.

The comparative example 6 omits the nano cerium oxide in the anti-oxidation layer, the performance of the coating is not as good as that of the coating in each aspect, because the nano cerium oxide has small particle size, large specific surface area and strong surface activity, the compactness of the anti-oxidation layer is improved when the nano cerium oxide is used in the anti-oxidation layer, the contact between oxygen in the air and the surface of the material is further prevented, and under the action of supersonic flame spraying, the raw material of the anti-oxidation layer is uniformly distributed on the transition layer and is partially fused with the surface of the transition layer, which is close to the anti-oxidation layer, so that the nano cerium oxide is firmly combined and is not easy to fall off.

The above embodiments are only preferred embodiments of the present invention, and the protection scope of the present invention is not limited thereby, and any insubstantial changes and substitutions made by those skilled in the art based on the present invention are within the protection scope of the present invention.