CN110629151A - A new type of electric heating coating and preparation method thereof - Google Patents

Abstract

The invention relates to a novel electric heating coating and a preparation method thereof, in particular to an electric heating coating which can be used for preventing and removing ice in the fields of vehicles, aerospace and the like, and relates to the technical field of thermal spraying and laser engraving. The preparation steps mainly comprise: a) inspecting the Al substrate; b) pretreating the surface of the Al substrate; c) spraying an electric heating coating on the surface of the Al substrate by using a thermal spraying technology; d) and (3) electrically heating the surface of the coating and performing laser engraving treatment. The invention has the advantages that: 1) an electrically heatable coating system of 3-layer structure was prepared by thermal spraying. 2) The invention designs a novel laser engraving process diagram, and forms discontinuous linear grooves on the surface of a coating by utilizing the interaction of laser and the coating, so that the conductive area of an electric heating coating is changed into a continuous linear shape, and the electric heating efficiency is increased. Compared with the existing electric heating coating structure, if an electrode layer is required to be prepared, the preparation process is simplified by combining the processes of thermal spraying and rapid forming technology (laser engraving treatment), and the electric heating coating structure is a novel electric heating coating structure.

Description

A new type of electric heating coating and preparation method thereof

technical field

The invention relates to the technical fields of thermal spraying and laser engraving, in particular to a novel electric heating coating and a preparation method thereof, which can be used for anti-icing and deicing purposes in the fields of vehicles, aerospace and the like.

Background technique

Anti-icing and de-icing of electric heating coating refers to constructing electric heating coating on the surface of wings and vehicle parts, and using the method of heating the coating to prevent ice on the surface of aircraft and vehicle parts. Traditional electric heating refers to arranging resistance wires on the inside of the base plate. After the resistance wire heats up, it transfers heat to the outside of the base plate to achieve the purpose of preventing and deicing. Therefore, the traditional method has the disadvantages of low energy utilization and high requirements on the heat transfer and heat resistance of the substrate, and it is required to be arranged in the substrate for internal measurement, which limits the scope of use. Compared with the traditional electric heating method, the electric heating coating is distributed on the outside of the substrate, which has low requirements on the heat transfer and heat resistance of the substrate, and is relatively less restricted by the use position, which broadens the use environment. Its heat energy is directly used for anti-icing and deicing, and the utilization rate of heat energy is high.

Thermal spraying technology is widely used to improve the special properties of the material surface due to its many types of spraying methods, wide range of spraying materials, simple process, economical benefits, and convenient operation. Surface strengthening occupies an indispensable position. Thermal sprayed NiCr alloy powder has excellent performance in thermal shock resistance and high temperature corrosion resistance. At the same time, NiCr alloy powder has the advantages of high heat resistance, large resistance, small temperature coefficient of resistance, large thermoelectric potential, etc. Materials commonly used in devices.

In the prior art, there has been research on new electric heating coatings. The patent application with application number 201610489651.0 prepares insulating layers, electrode layers (prepared by magnetron sputtering, chemical plating, electroplating, etc.), electric heating layers, protection layers on the surface of the substrate The 4-layer electric heating coating system makes the heating more uniform and achieves the purpose of preventing and deicing, but the preparation process of the electric heating coating and electrode layer is more complicated.

In the application document with the application number of 201710248415.4 about an electric heating technology for aircraft anti-icing/de-icing, the surfaces such as wings are coated with electrothermal coatings such as silver, polyurethane and carbon fiber through a coating process to form an electrothermal coating, and a power supply The combination of system and control system achieves the purpose of anti-icing/de-icing. However, the selection of coating materials in this process is limited and the coating quality is poor.

SUMMARY OF THE INVENTION

The purpose of the present invention is to solve the problems of complex process, few types of coating materials, poor coating quality, etc. existing in the production and preparation process of the electric heating coating in the prior art, so as to provide a simple preparation process and provide more The invention discloses an electric heating coating with coating material selection, good coating quality and high coating electric heating efficiency and a preparation method thereof.

To achieve the above object, the present invention is achieved by the following means:

The present invention provides a novel electric heating coating, which can be used for anti-icing and deicing purposes in the fields of vehicles, aerospace, etc. The novel electric heating coating includes an Al substrate and an electric heating layer, and the electric heating layer includes a bonding layer , an electrical insulating layer, a conductive layer, the bonding layer is a NiCr coating, the electrical insulating layer is Al ₂ O ₃ , and the conductive layer is a NiCr coating;

Preferably, the thickness of the bonding layer is 0.03-0.10mm, the thickness of the electrical insulating layer is 0.10-0.25mm, and the thickness of the conductive layer is 0.03-0.12mm;

Preferably, the thickness of the bonding layer is 0.03-0.05mm, the thickness of the electrical insulating layer is 0.10-0.15mm, and the thickness of the conductive layer is 0.03-0.05mm;

Preferably, a plurality of discontinuous line grooves are formed on the surface of the electric heating layer, the line grooves are parallel and equidistant, the line groove width is c, and the line groove length is smaller than the width of the electric heating layer, The distance a is different from the width of the electric heating layer, and the distance between two adjacent line grooves is b, where a is 0.9-1.2 mm, b is 0.1-0.2 mm, and c is 0.1-0.2 mm.

The present invention further provides a preparation method of a novel electric heating coating, comprising the following steps:

(a) Use detection methods to detect the Al substrate to check whether there are specific defects on the surface of the Al substrate;

(b) pretreating the surface of the Al substrate inspected in step (a);

(c) The electric heating coating is sprayed on the surface of the pretreated Al substrate by thermal spraying technology;

(d) Laser engraving is performed on the surface of the electric heating layer.

Preferably, the detection means described in step (a) is selected from one or more including but not limited to naked eye observation, optical microscope sampling observation, scanning electron microscope sampling observation, and surface roughness detection;

Preferably, the specific defect in step (a) is selected from one or more including but not limited to scratches, voids, and miscellaneous inclusions;

Preferably, the pretreatment in step (b) includes degreasing and/or sandblasting; most preferably, the degreasing is selected from the group consisting of but not limited to flame burning, alcohol cleaning, acetone cleaning, or In various ways, the sand particles used in the sandblasting are selected from 12-45# brown corundum, and the sandblasting pressure is: 0.25-0.65MPa;

Preferably, in the step (c), the thermal spraying technology is selected from one or more including but not limited to atmospheric plasma spraying technology (APS) and low pressure plasma spraying technology (LPPS);

Preferably, in step (d), the laser engraving process forms a plurality of discontinuous line grooves on the surface of the electric heating layer, the line grooves are parallel and equidistant, the line groove width is c, and the line grooves are The depth is h, the length of the line groove is less than the width of the electric heating layer, and the distance a difference from the width of the electric heating layer, the distance between two adjacent line grooves is b, the a is 0.9-1.2mm, and b is 0.1-0.2mm , c is 0.1-0.2mm, h is 0.06-0.20mm;

Preferably, the depth h of the line groove is 0.06-0.13 mm.

Specifically, the second purpose of the present invention is to provide a novel electric heating coating structure, comprising the following steps:

(a) Use detection methods to detect the Al substrate to check whether there are specific defects on the surface of the Al substrate;

(b) pretreating the surface of the inspected Al substrate;

(c) The electric heating coating is sprayed on the surface of the pretreated Al substrate by thermal spraying technology;

(d) Laser engraving is performed on the surface of the electrically heated coating. The schematic diagram of the laser engraving process is shown in Figure 1. After laser treatment, discontinuous line grooves are formed on the surface of the coating. The width of the line groove is c, the length of the line groove is less than the width of the coating layer, and the difference is a distance a from the width of the coating layer. The line groove and the line groove are parallel and equidistant. , the distance is b, one end of the line groove 1 is flush with one end of the coating, the other end of the line groove 2 is flush with the other end of the coating, so as to alternately arrange, the distance a is 0.9-1.2mm, and the groove spacing b is 0.1-0.2mm, groove width c is 0.1-0.2mm.

The schematic diagram of the structure of the new type of electric heating coating is shown in Figure 2. After connecting the electrodes 1 at both ends, the current passes through the surface of the electric heating coating, and the coating is energized and heated to achieve the purpose of preventing and deicing. The current is directed by the arrows in Figure 2. shown.

Compared with the prior art, the present invention has the following advantages:

(1) Three-layer structure of electric heating coating was prepared by traditional thermal spraying method;

(2) Through the rapid prototyping technology (laser engraving process), the heating efficiency of the electric heating coating is improved;

(3) Using thermal spraying and laser engraving technology to broaden the types of coating materials, and prepare an electric heating coating system with good coating quality;

(4) This patent uses thermal spraying technology to prepare a three-layer electric heating coating system of bonding layer, electrical insulating layer and conductive layer, and uses laser to interact with the coating to form discontinuous line grooves on the surface of the coating to make the electric heating The conductive area of the coating becomes a continuous line, increasing the electric heating efficiency.

Description of drawings

Fig. 1 is the electric heating coating engraving process schematic diagram of the present invention;

Fig. 2 electric heating coating structure diagram of the present invention;

Among them: 1, electrode; 2, line groove; 3, Al substrate; 4, bonding layer; 5, electrical insulating layer; 6, conductive layer; a, the distance between the length of the line groove and the width of the coating; b, phase The distance between two adjacent line grooves; c, the width of the line grooves.

Detailed ways

In order to make the purpose, technical scheme and effect of the present invention clearer and clearer, the present invention will be further described in detail below with reference to examples and comparative examples. It should be understood that the specific embodiments described herein are only used to explain the present invention, but not to limit the present invention.

Example 1

A preparation method of a novel electric heating coating, comprising the following steps:

(a) Use the naked eye to inspect the Al substrate 3 to see if the Al substrate 3 has scratches, voids, and inclusions;

(b) using acetone to wipe the above-mentioned Al substrate 3 to remove the oil stains on the surface of the Al substrate 3, and then use 45# brown corundum, and the pressure of 0.5MPa to blast the above-mentioned Al substrate 3;

(c) Using NiCr and Al ₂ O ₃ powders as raw material powders, and using atmospheric plasma spraying technology (APS), firstly, a NiCr coating with a thickness of 0.03 mm is sprayed on the surface of the Al substrate 3 as a primer as the bonding layer 4 , and the bonding layer 4 is detected. The bonding strength reaches 45MPa, and then Al ₂ O ₃ is sprayed on the bonding layer 4 to form an electrical insulating layer 5 with a thickness of 0.09mm, and then continues to spray NiCr as a conductive layer 6 with a thickness of 0.04mm;

(d) Use laser engraving technology to engrave line grooves 2 on the surface of the electric heating coating as shown in Figure 1. The distance a is about 1.0mm, the distance b is about 0.141mm, and the distance c is about 0.165mm. The depth of the line groove 2 h is about 0.071mm, that is, the microhardness of the coating of the conductive layer 6 is 247HV0.3, the porosity is 1.9%, and the oxide content is 6.5%; the microhardness of the coating of the insulation layer 5 is 751HV0.3, The porosity was 1.0%.

Example 2

A preparation method of a novel electric heating coating, comprising the following steps:

(a) Use the naked eye to inspect the Al substrate 3 to see if the Al substrate 3 has scratches, voids, and inclusions;

(b) use acetone to wipe the above-mentioned Al substrate 3, remove the oil stain on the surface of the Al substrate 3, then use 45# brown corundum, and the pressure of 0.5MPa to carry out sandblasting to the above-mentioned Al substrate 3;

(c) Using NiCr and Al ₂ O ₃ powders as raw material powders, using low pressure plasma spraying technology (LPPS) to spray a NiCr coating with a thickness of 0.04 mm on the surface of the Al substrate 3 as a primer as the bonding layer 4 , and detecting the bonding strength of the bonding layer 4 up to 48MPa, then spray Al ₂ O ₃ on the bonding layer 4 as the electrical insulating layer 5 with a thickness of 0.10mm, and then continue to spray the NiCr coating as the conductive layer 6 with a thickness of 0.03mm;

(d) Use laser engraving technology to engrave line grooves 2 on the surface of the electric heating coating as shown in Figure 1, the distance a is about 1.0mm, the distance b is about 0.152mm, the distance c is about 0.151mm, and the depth of the line groove is h It is about 0.067mm, that is, the microhardness of the coating of the conductive layer 6 is 293HV0.3, the porosity is 1.0%, and the oxide content is 5.5%; the microhardness of the coating of the insulation layer 5 is 834HV0.3, and the pores The rate is 0.9%.

Example 3

A preparation method of a novel electric heating coating, comprising the following steps:

(a) Use the naked eye to inspect the Al substrate 3 to see if the Al substrate 3 has scratches, voids, and inclusions;

(b) using acetone and alcohol to wipe the above-mentioned Al substrate 3 to remove the oil stains on the surface of the Al substrate 3, and then use 45# brown corundum, and the pressure of 0.5MPa to blast the above-mentioned Al substrate 3;

(c) Using NiCr and Al ₂ O ₃ powders as raw material powders, using atmospheric plasma spraying (APS) to spray a NiCr coating with a thickness of 0.04 mm on the surface of the Al substrate 3 as a primer as the bonding layer 4, and detecting that the bonding strength of the bonding layer 4 reaches 42MPa, and then spray Al ₂ O ₃ on the bonding layer 4 as an electrical insulating layer with a thickness of 0.12mm, and then continue to spray NiCr coating as a conductive layer 5 with a thickness of 0.04mm;

(d) Use laser engraving technology to engrave line groove 2 on the surface of the electric heating coating as shown in Figure 1, the distance a is about 1.0mm, the distance b is about 0.119mm, the distance c is about 0.186mm, and the depth of the groove 2 is h It is about 0.078mm, that is, the microhardness of the coating of the conductive layer 6 is 267HV0.3, the porosity is 1.2%, and the oxide content is 7.0%; the microhardness of the coating of the insulating layer 5 is 785HV0.3, and the porosity The rate was 1.1%.

The above-mentioned section of the detailed description has made a specific introduction to the analysis method involved in the present invention. It should be noted that the above description is only for helping those skilled in the art to better understand the method and idea of the present invention, rather than limiting the related content. Without departing from the principles of the present invention, those skilled in the art can also make appropriate adjustments or modifications to the present invention, and the above adjustments and modifications should also belong to the protection scope of the present invention.

Claims (10)

1. a novel electric heating coating is characterized in that, comprises Al substrate and electric heating layer, and described electric heating layer comprises bonding layer, electric insulating layer, conductive layer, described bonding layer is NiCr coating, described electric heating layer is NiCr coating. The insulating layer is Al ₂ O ₃ , and the conductive layer is a NiCr coating. 2 . The novel electric heating coating according to claim 1 , wherein the thickness of the bonding layer is 0.03-0.10 mm, the thickness of the electrical insulating layer is 0.10-0.25 mm, and the thickness of the conductive layer is 0.03-0.12 mm. 3 . 3. The novel electric heating coating according to claim 2, wherein the thickness of the bonding layer is 0.03-0.05mm, the thickness of the electrical insulating layer is 0.10-0.15mm, and the thickness of the conductive layer is 0.03-0.05mm. 4. The novel electric heating coating according to claim 1, wherein a plurality of discontinuous line grooves are formed by engraving on the surface of the electric heating layer, and the line grooves are parallel and equidistant. The width of the groove is c, the length of the line groove is less than the width of the electric heating layer, and the difference from the width of the electric heating layer is a distance a, and the distance between two adjacent line grooves is b, the a is 0.9-1.2mm, and b is 0.1- 0.2mm, c is 0.1-0.2mm. 5. according to the preparation method of the described novel electric heating coating of any one of claim 1-4, comprise the steps: (a) Use detection methods to detect the Al substrate to check whether there are specific defects on the surface of the Al substrate; (b) pretreating the surface of the Al substrate inspected in step (a); (c) The electric heating coating is sprayed on the surface of the pretreated Al substrate by thermal spraying technology; (d) Laser engraving is performed on the surface of the electric heating layer. 6. preparation method according to claim 5, is characterized in that, the detection means described in step (a) is selected from among including but not limited to naked eye observation, optical microscope sampling observation, scanning electron microscope sampling observation, surface roughness detection. one or more. 7 . The preparation method according to claim 5 , wherein the specific defects in step (a) are selected from one or more of scratches, voids, and miscellaneous inclusions, but not limited to. 8 . 8. The preparation method according to claim 5, wherein the pretreatment in step (b) comprises degreasing and/or sandblasting; most preferably, the degreasing is selected from the group consisting of, but not limited to, flame One or more methods of burning, alcohol cleaning, and acetone cleaning, the sand used for the sandblasting is selected from 12-45# brown corundum, and the sandblasting pressure is: 0.25-0.65MPa. 9. preparation method according to claim 5 is characterized in that, described in step (c), thermal spraying technology is selected from one including but not limited to atmospheric plasma spraying technology (APS), low pressure plasma spraying technology (LPPS). species or several. 10 . The preparation method according to claim 5 , wherein the laser engraving process in step (d) forms a plurality of discontinuous line grooves on the surface of the electric heating layer, and the line grooves are parallel and equidistant. 11 . , the width of the line groove is c, the depth of the line groove is h, the length of the line groove is smaller than the width of the electric heating layer, and the difference from the width of the electric heating layer is a distance a, and the distance between two adjacent line grooves is b. a is 0.9-1.2mm, b is 0.1-0.2mm, c is 0.1-0.2mm, and h is 0.06-0.20mm.