阅读说明：本技术 一种金属渐变性高温太阳能吸收涂层及其制备方法 (Metal gradual-change high-temperature solar energy absorption coating and preparation method thereof ) 是由 高祥虎 刘刚 于 2019-10-11 设计创作，主要内容包括：本发明涉及一种金属渐变性高温太阳能吸收涂层,该涂层依次由抛光不锈钢片构成的吸热体基底、高金属含量AlCrTaTiZrN构成的主吸收层、低金属含量AlCrTaTiZrN构成的次吸收层和Al<Sub>2</Sub>O<Sub>3</Sub>构成的减反射层组成。主吸收层是指采用等摩尔比的金属Al、Cr、Ta、Ti、Zr在2sccm≤氮气流量<6sccm的条件下通过熔炼法制备的AlCrTaTiZr高熵合金的氮化物；次吸收层是指采用等摩尔比的金属Al、Cr、Ta、Ti、Zr在6sccm≤氮气流量≤10sccm的条件下通过熔炼法制备的AlCrTaTiZr高熵合金的氮化物。本发明还公开了该涂层的制备方法。本发明制备工艺简单、成本较低,所制备的涂层在大气质量因子AM1.5条件下,吸收率≥0.94,发射率<0.10；且该涂层在空气500℃具有良好的长期热稳定性能。(The invention relates to a metal gradual-change high-temperature solar energy absorbing coating, which sequentially comprises a heat absorbing body substrate formed by a polished stainless steel sheet, a main absorbing layer formed by high-metal content AlCrTaTiZrN, a secondary absorbing layer formed by low-metal content AlCrTaTiZrN and Al 2 O 3 And the formed antireflection layer. The main absorption layer adopts the nitrogen flow of the metals Al, Cr, Ta, Ti and Zr with equal molar ratio under 2sccm or less<The nitride of the AlCrTaTiZr high-entropy alloy is prepared by a smelting method under the condition of 6 sccm; the secondary absorption layer is the nitride of AlCrTaTiZr high-entropy alloy prepared by adopting metals Al, Cr, Ta, Ti and Zr with equal molar ratio through a smelting method under the condition that the nitrogen flow is less than or equal to 6sccm and less than or equal to 10 sccm. The invention also discloses a preparation method of the coating. The preparation method has the advantages of simple preparation process and low cost, and the prepared coatingUnder the condition of an atmospheric quality factor AM1.5, the absorptivity is more than or equal to 0.94, and the emissivity<0.10; and the coating has good long-term thermal stability at 500 ℃ in air.)

1. A metal gradual change high temperature solar energy absorption coating which is characterized in that: the coating comprises a heat absorbing body substrate formed by a polished stainless steel sheet, a main absorbing layer formed by high metal content AlCrTaTiZrN, a secondary absorbing layer formed by low metal content AlCrTaTiZrN and Al in sequence₂O₃The formed antireflection layer; the main absorption layer adopts the nitrogen flow of metals Al, Cr, Ta, Ti and Zr with equal molar ratio and the nitrogen flow is less than or equal to 2sccm<The nitride of the AlCrTaTiZr high-entropy alloy is prepared by a smelting method under the condition of 6 sccm; the secondary absorption layer is the nitride of AlCrTaTiZr high-entropy alloy prepared by adopting metals Al, Cr, Ta, Ti and Zr with equal molar ratio through a smelting method under the condition that the nitrogen flow is less than or equal to 6sccm and less than or equal to 10 sccm.

2. The metal-graded high temperature solar absorber coating of claim 1, wherein the roughness value of said absorber substrate is 0.5 ~ 3 nm.

3. The solar absorptive coating of claim 1, wherein the thickness of the primary absorption layer is 30 ~ 65 nm.

4. The solar absorptive coating of claim 1, wherein the thickness of the sub-absorption layer is 35 ~ 56 nm.

5. The metal-graded high temperature solar absorptive coating according to claim 1, wherein the anti-reflective layer has a thickness of 40 ~ 70 nm.

6. A metal-graded high temperature solar absorptive coating as claimed in claim 1, wherein: the AlCrTaTiZr high-entropy alloy is prepared by putting Al, Cr, Ta, Ti and Zr with equal molar ratio into a graphite crucible, then putting the graphite crucible into a vacuum smelting furnace, and vacuumizing to 3.5 multiplied by 10^-6~7×10^-6And (3) Torr, melting at 2300 ~ 2700 ℃, pouring and molding, and cutting and polishing to obtain the product.

7. The method for preparing a metal-graded high temperature solar absorptive coating of claim 1, comprising the steps of:

processing a heat absorbing body substrate;

preparing a main absorption layer on the treated heat absorption body substrate, wherein AlCrTaTiZr high-entropy alloy with the purity of 99.9 percent is used as a sputtering target material and is prepared by adopting a radio frequency reaction magnetron sputtering method in argon and nitrogen atmosphere, and the working parameters are that the sputtering power density of the AlCrTaTiZr target material is 3.0 ~ 6.5.5W/cm^-2The air inflow of the argon during sputtering deposition is 20 ~ 60sccm, and the air inflow of the nitrogen is less than or equal to 2sccm<6sccm, the thickness of the deposited AlCrTaTiZrN is 30 ~ 65 nm;

thirdly, preparing a secondary absorption layer on the main absorption layer, namely preparing the secondary absorption layer by taking AlCrTaTiZr high-entropy alloy with the purity of 99.9 percent as a sputtering target material and adopting a radio frequency reaction magnetron sputtering method in the atmosphere of argon and nitrogen, wherein the working parameter is that the sputtering power density of the AlCrTaTiZr target material is 3.0 ~ 6.5.5W/cm^-2The air inflow of argon during sputtering deposition is 20 ~ 60sccm, the air inflow of nitrogen is more than or equal to 6sccm and less than or equal to 10sccm, and the thickness of deposited AlCrTaTiZrN is 35 ~ 56 nm;

preparing an antireflection layer on the secondary absorption layer: al with a purity of 99.99%₂O₃The target material is prepared by adopting a radio frequency magnetron sputtering method in an argon atmosphere; wherein the working parameters are as follows: al (Al)₂O₃The sputtering power density of the target is 5.5 ~ 10W-cm^-2The air inflow of the argon gas during the sputtering deposition is 20 ~ 60sccm, and the deposition thickness is 40 ~ 70 nm.

8. The method for preparing the metal-graded high-temperature solar energy absorption coating according to claim 7, wherein the heat absorber substrate treatment in the step is ultrasonic cleaning in acetone and absolute ethyl alcohol for 10 ~ 20 minutes respectively after removing impurities attached to the surface of polished stainless steel sheets of the substrate, and drying and storing with nitrogen.

Technical Field

The invention relates to the technical field of high-temperature solar energy absorbing coatings for solar photo-thermal power generation, in particular to a metal gradual-change high-temperature solar energy absorbing coating and a preparation method thereof.

Background

Currently, under the background that non-renewable energy such as fossil and the like becomes scarce day by day, the world energy structure will change greatly, solar energy will gradually replace conventional energy and become indispensable important energy, and research on photo-thermal utilization thereof has been a hot spot at present. Solar energy utilization at high temperature in solar concentration thermal power generation is a development trend of solar energy utilization in the future, wherein trough type concentration power generation is one of main forms of photo-thermal power generation.

The high-temperature heat collecting tube is a core component of the groove type photo-thermal power generation, and the high-temperature solar energy absorbing coating is a core material for realizing photo-thermal conversion and improving the yield of a power station. The metal-doped dielectric system is a common film system of a high-temperature solar energy absorption coating, but under the high-temperature working condition, the coating is easy to oxidize and diffuse metal atoms, so that the optical performance is attenuated. Therefore, the application of the new material in the solar energy absorption coating and the establishment of different film system structures are significant.

Disclosure of Invention

The invention aims to provide a metal gradual-change high-temperature solar energy absorption coating and a preparation method thereof.

The invention also provides a preparation method of the metal gradual-change high-temperature solar energy absorption coating.

In order to solve the problems, the invention provides a metal-graded high-temperature solar energy absorption coating, which is characterized in that: the coating comprises a heat absorbing body substrate formed by polished stainless steel sheet, a main absorbing layer formed by high metal content AlCrTaTiZrN (high metal volume fraction), a secondary absorbing layer formed by low metal content AlCrTaTiZrN (low metal volume fraction) and Al in sequence₂O₃The formed antireflection layer; the main absorption layer adopts the nitrogen flow of metals Al, Cr, Ta, Ti and Zr with equal molar ratio and the nitrogen flow is less than or equal to 2sccm<The nitride of the AlCrTaTiZr high-entropy alloy is prepared by a smelting method under the condition of 6 sccm; the secondary absorption layer is the nitride of AlCrTaTiZr high-entropy alloy prepared by adopting metals Al, Cr, Ta, Ti and Zr with equal molar ratio through a smelting method under the condition that the nitrogen flow is less than or equal to 6sccm and less than or equal to 10 sccm.

The roughness value of the absorber substrate was 0.5 ~ 3 nm.

The thickness of the main absorption layer is 30 ~ 65 nm.

The thickness of the secondary absorption layer is 35 ~ 56 nm.

The thickness of the antireflection layer is 40 ~ 70 nm.

The AlCrTaTiZr high-entropy alloy is prepared by putting Al, Cr, Ta, Ti and Zr with equal molar ratio into a graphite crucible, then putting the graphite crucible into a vacuum smelting furnace, and vacuumizing to 3.5 multiplied by 10^-6~7×10^-6And (3) Torr, melting at 2300 ~ 2700 ℃, pouring and molding, and cutting and polishing to obtain the product.

The preparation method of the metal-graded high-temperature solar energy absorption coating comprises the following steps:

processing a heat absorbing body substrate;

preparing a main absorption layer on the treated heat absorption body substrate, wherein AlCrTaTiZr high-entropy alloy with the purity of 99.9 percent is used as a sputtering target material and is prepared by adopting a radio frequency reaction magnetron sputtering method in argon and nitrogen atmosphere, and the working parameters are that the sputtering power density of the AlCrTaTiZr target material is 3.0 ~ 6.5.5W/cm^-2The air inflow of the argon during sputtering deposition is 20 ~ 60sccm, and the air inflow of the nitrogen is less than or equal to 2sccm<6sccm, the thickness of the deposited AlCrTaTiZrN is 30 ~ 65 nm;

thirdly, preparing a secondary absorption layer on the main absorption layer, namely preparing the secondary absorption layer by taking AlCrTaTiZr high-entropy alloy with the purity of 99.9 percent as a sputtering target material and adopting a radio frequency reaction magnetron sputtering method in the atmosphere of argon and nitrogen, wherein the working parameter is that the sputtering power density of the AlCrTaTiZr target material is 3.0 ~ 6.5.5W/cm^-2The air inflow of argon during sputtering deposition is 20 ~ 60sccm, the air inflow of nitrogen is more than or equal to 6sccm and less than or equal to 10sccm, and the thickness of deposited AlCrTaTiZrN is 35 ~ 56 nm;

preparing an antireflection layer on the secondary absorption layer: al with a purity of 99.99%₂O₃The target material is prepared by adopting a radio frequency magnetron sputtering method in an argon atmosphere; wherein the working parameters are as follows: al (Al)₂O₃The sputtering power density of the target is 5.5 ~ 10W/cm^-2The air inflow of the argon gas during the sputtering deposition is 20 ~ 60sccm, and the deposition thickness is 40 ~ 70 nm.

The heat absorber substrate treatment in the step refers to that after impurities attached to the surface of a polished stainless steel sheet of the substrate are removed, the polished stainless steel sheet is ultrasonically cleaned in acetone and absolute ethyl alcohol for 10 ~ 20 minutes respectively, and nitrogen is dried and stored.

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

1. the invention adopts AlCrTaTiZrN high-entropy alloy as a target material, and the sputtering deposition is to prepare the high-temperature solar energy absorbing coating with metal gradual change property by regulating and controlling the content of nitrogen.

2. The coating prepared by the invention has the advantages that under the condition of an atmospheric quality factor AM1.5, the absorptivity is more than or equal to 0.94, and the emissivity is less than 0.10; and the coating has good long-term thermal stability at 500 ℃ in air.

3. The invention has simple preparation process and lower cost.

Drawings

The following describes embodiments of the present invention in further detail with reference to the accompanying drawings.

FIG. 1 is a block diagram of the present invention.

Detailed Description