Method for preparing protective layer on thermal protection material oxide layer
By preparing an inert metal conductive layer and a nickel film on the oxide layer of the thermal protection material, the problems of unevenness and damage in the preparation of the Ni layer protective layer are solved, the protection of the oxide layer and the reliability of the research are achieved, and the preparation cost is reduced.
Patent Information
- Application Number
- CN202510936481.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-08
- Publication Date
- 2025-09-23
AI Technical Summary
In the prior art, when preparing the Ni protective layer, problems such as uneven arcing, target burning and ion sputtering that damage the oxide layer on the surface of the material are prone to occur, resulting in damage to the oxide layer of the thermal protection material during the grinding and polishing process.
An inert metal conductive layer is prepared on the oxide layer of the thermal protection material, a stable conductive layer is formed by ion sputtering, and then a nickel film is electroplated by constant potential deposition to form a protective structure of the metal conductive layer and the nickel metal layer.
It effectively avoids damage to the oxide layer during the grinding and polishing process, ensures the integrity of the oxide layer, and is conducive to subsequent research. The plating solution is low in cost, environmentally friendly and efficient, and does not affect the oxide layer detection results.
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Figure CN120683497A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of high-temperature alloy or surface engineering protection, and in particular to a method for preparing a protective layer on an oxide layer of a heat protection material. Background Art
[0002] As the current aviation engine, gas turbine and nuclear power industries are developing towards low pollution and high efficiency, more and more research is being conducted on thermal protection materials, whether metal alloys or protective coatings.
[0003] In fundamental research, the microstructure of the oxide layer of heat-resistant materials is increasingly being studied in depth, which requires that the oxide layer on the surface of the heat-resistant material be intact. Therefore, when studying the cross-sectional morphology of the oxide layer of heat-resistant materials and the changes in its microstructure and structure during oxidation, a metal protective layer must be prepared on the surface to prevent cracking and flaking during grinding and polishing.
[0004] Currently, commonly used metal protective layers are relatively soft metal layers, such as Al or Ni protective layers. For the preparation of Ni protective layers, there are public publications using arc ion plating techniques to prepare Ni layers. However, Ni is a highly magnetic material, and arc ion plating is prone to arcing spots, uneven arcing, and target burning. Furthermore, during the arc ion plating process, ion sputtering damages the oxide layer on the material surface, resulting in high production costs and numerous limitations.
[0005] In view of this, the present invention is proposed. Summary of the Invention
[0006] The object of the present invention is to provide a method for preparing a protective layer on the oxide layer of a thermal protective material, by which a stable nickel film that does not damage the oxide layer can be plated on the surface of the oxide layer of the thermal protective material, thereby effectively avoiding damage to the oxide layer of the thermal protective material during the grinding and polishing process.
[0007] The present invention is achieved in that: In a first aspect, the present invention provides a method for preparing a protective layer on an oxide layer of a thermal protection material, comprising: preparing an inert metal conductive layer on the surface of the oxide layer of the thermal protection material by an ion sputtering method, and then performing a nickel plating treatment on the surface by a constant potential deposition method to obtain a nickel metal layer; Wherein, the metal element of the inert metal conductive layer is selected from at least one of gold, platinum and copper.
[0008] In some embodiments, the metal element of the inert metal conductive layer is gold.
[0009] In some embodiments, the method for preparing the inert metal conductive layer includes: placing a thermal protection material with an oxide layer in a vacuum chamber of an ion sputtering apparatus, evacuating the chamber, and then performing ion sputtering to obtain the inert metal conductive layer.
[0010] In some embodiments, the vacuum degree of the ion sputtering environment is controlled at 10 -3 Below Pa, the sputtering time is 30~120s.
[0011] In some embodiments, the method for preparing the nickel metal layer includes: placing the thermal protection material with the prepared inert metal conductive layer into the electroplating solution, and using the obtained inert metal conductive layer as the cathode and the nickel mesh or nickel plate as the anode, and adopting a constant potential deposition method to electroplate a layer of nickel film.
[0012] In some embodiments, the electroplating conditions are: current density 15-60 mA / cm 2 , electroplating time 10~60 min, electroplating temperature 10~50 ℃.
[0013] In some embodiments, the electroplating solution includes: 0.02-1.2 mol / L nickel chloride hexahydrate, 0.02-0.15 mol / L nickel sulfate hexahydrate, and 0.1-0.5 mol / L pH buffer.
[0014] In some embodiments, pH buffers include acetic acid, phosphoric acid, and citric acid.
[0015] In a second aspect, the present invention provides a protective layer of the oxide layer of the thermal protection material obtained by the above method, wherein the protective layer comprises an inert metal conductive layer and a nickel metal layer sequentially formed on the surface of the oxide layer.
[0016] In a third aspect, the present invention provides an application of the above-mentioned protective layer in the study of the microstructure of the oxide layer of a thermal protection material.
[0017] The present invention has the following beneficial effects: (1) The present invention adds a step of pretreating the oxide layer of the thermal protection material before electroplating the nickel film on the surface of the oxide layer of the thermal protection material. A metal conductive layer is formed on the surface of the oxide layer through pretreatment, and then the nickel film is electroplated on the surface. The obtained thermal protection material with a nickel metal layer and a metal conductive layer can protect the integrity of the oxide film and effectively avoid damage to the oxide layer of the thermal protection material during the grinding and polishing process.
[0018] (2) After the thermal protection material of the present invention is electroplated, the nickel film on its surface has no negative impact on the oxide layer and the thermal protection material, which is beneficial for researchers to conduct failure studies on the thermal protection material and reduce errors.
[0019] (3) The raw materials of the plating solution of the present invention are stable and readily available, and do not contain precious metals, concentrated acids, concentrated alkalis, etc. The plating solution is low in cost and energy-saving, environmentally friendly, and highly efficient. Furthermore, the plating solution proposed in the present invention is a weak acid system that does not react with the thermal protection material and its oxide layer, thus simplifying the operation of nickel film preparation and reducing the requirements for equipment and process, thus better serving researchers. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.
[0021] Figure 1 This is the SEM image of the oxide layer after pretreatment and before electroplating in Example 1; Figure 2 This is a SEM image of the cross-sectional morphology of the Ni layer prepared on the surface of the oxide layer of the thermal protection material in Example 2; Figure 3 This is a SEM image of the cross-sectional morphology of the Ni layer prepared on the surface of the oxide layer of the thermal protection material in Example 3; Figure 4 This is an SEM image of the cross-sectional morphology of comparative example 1 in which no Ni layer is prepared on the surface of the oxide layer of the thermal protection material. DETAILED DESCRIPTION
[0022] To make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer are used. Where the manufacturer of the reagents or instruments is not specified, all are conventional products that can be purchased commercially.
[0023] As described in the background art, in order to study the microstructure of the oxide layer on the surface of the thermal protection material, researchers in this field will prepare a soft metal protective layer on the surface of the oxide layer to prevent the oxide layer from cracking and peeling during the grinding and polishing process. Conventional soft metal protective layers are Al or Ni protective layers. However, when preparing the Ni protective layer, arc ion plating technology is prone to problems such as uneven arcing and target burning. There is also a problem that the oxide layer on the surface of the material is damaged during the ion sputtering operation. In order to improve the above problems, the present invention provides a new protective layer on the oxide layer of the thermal protection material. The preparation method is to pre-treat the nickel film on the oxide layer before preparing it to form a metal conductive layer. In this way, the integrity of the oxide layer of the thermal protection material can be protected, and the damage of the oxide layer of the thermal protection material during the grinding and polishing process can be effectively avoided.
[0024] The method for preparing a protective layer on an oxide layer of a thermal protection material provided by the present invention comprises: An inert metal conductive layer is prepared on the surface of the oxide layer of the thermal protection material by an ion sputtering method, and then nickel is plated on the surface by a constant potential deposition method to obtain a nickel metal layer.
[0025] Wherein, the metal element of the inert metal conductive layer is selected from at least one of gold, platinum and copper.
[0026] In some embodiments, the metal element of the inert metal conductive layer is gold.
[0027] The advantage of using the above-mentioned metal elements to prepare the inert metal conductive layer is that the conductive layer has stable chemical properties, will not dissolve in the plating solution, and will not interfere with the detection results of the oxide layer.
[0028] In some embodiments, the preparation method of the inert metal conductive layer is specifically as follows: ion sputtering a layer of inert metal conductive layer on the oxide layer of the thermal protection material to be electroplated, placing the thermal protection material with the oxide layer in the vacuum chamber of an ion sputtering instrument for vacuuming, and taking out the sample after ion sputtering for use.
[0029] In some embodiments, the vacuum degree of the ion sputtering environment is controlled at 10 -3 Pa, the sputtering time is 30~120s. Specifically, the vacuum degree can be 1×10 -3 Pa, can also be 9×10 -4 Pa, 8×10 -4 Pa, 7×10 -4 Pa, 6×10 -4 Pa, 5×10 -4 Pa, 1×10 -4 Pa, 1×10 -5 Pa, as long as the vacuum degree is maintained at 10 -3The sputtering time can be 30s, 40s, 50s, 60s, 70s, 80s, 90s, 100s, 110s or 120s, or any other value between 30 and 120s.
[0030] The present invention controls the thickness of the above-mentioned inert metal conductive layer by controlling the sputtering time. The thickness of the inert metal conductive layer prepared within the above-mentioned sputtering time can meet the needs of subsequent nickel plating and morphology and structure research, and will not cause problems such as discontinuous Ni layer plating and inability to completely cover the surface due to being too thin.
[0031] In some embodiments, the nickel plating process includes placing a heat-protective material with a prepared inert metal conductive layer into an electroplating solution, and using the obtained inert metal conductive layer as a cathode and a nickel mesh or nickel plate as an anode to electroplate a nickel film using a constant potential deposition method.
[0032] In some embodiments, the electroplating conditions are: current density 15-60 mA / cm 2 , electroplating time 10~60 min, electroplating temperature 10~50℃. Specifically, the electroplating current density can be 15 mA / cm 2 , 20 mA / cm 2 , 25 mA / cm 2 , 30 mA / cm 2 , 35 mA / cm 2 , 40 mA / cm 2 , 45 mA / cm 2 , 50 mA / cm 2 , 55 mA / cm 2 or 60 mA / cm 2 , can also be 15~60mA / cm 2 the electroplating time may be 10 min, 20 min, 30 min, 40 min, 50 min or 60 min, or any other value between 10 and 60 min; the electroplating temperature may be 10°C, 15°C, 20°C, 25°C, 30°C, 35°C, 40°C, 45°C or 50°C, or any other value between 10 and 50°C.
[0033] The thickness of the nickel film prepared by the above method can be 2 to 20 μm, preferably 3 to 15 μm. When the thickness is below this range, the nickel film has no protective effect, and when it is too thick, the preparation cost will be increased.
[0034] In some embodiments, the components of the electroplating solution are nickel chloride hexahydrate, nickel sulfate hexahydrate, and a pH buffer.
[0035] In some embodiments, the components of the electroplating solution are: 0.02-1.2 mol / L nickel chloride hexahydrate, 0.02-0.15 mol / L nickel sulfate hexahydrate, and 0.1-0.5 mol / L pH buffer. Specifically, the concentration of nickel chloride hexahydrate may be 0.02 mol / L, 0.05 mol / L, 0.1 mol / L, 0.2 mol / L, 0.5 mol / L, 0.6 mol / L, 0.8 mol / L, 1 mol / L or 1.2 mol / L, or any other value between 0.02 and 1.2 mol / L; the concentration of nickel sulfate hexahydrate may be 0.02 mol / L, 0.03 mol / L, 0.04 mol / L, 0.05 mol / L, 0.08 mol / L, 0.1 mol / L, 0.12 mol / L or 0.15 mol / L, or any other value between 0.02 and 0.15 mol / L; the concentration of the pH buffer may be 0.1 mol / L, 0.2 mol / L, 0.3 mol / L, 0.4 mol / L or 0.5 mol / L, or any other value between 0.1 and 0.5 mol / L.
[0036] In some embodiments, the pH buffer is a weak acid, including acetic acid, phosphoric acid, and citric acid. Preferably, the pH buffer is a phosphate buffer.
[0037] The electroplating solution of the present invention is made from stable and readily available raw materials, does not contain precious metals, concentrated acids, or concentrated bases, and is low-cost, energy-efficient, environmentally friendly, and highly effective. Furthermore, the plating solution of the present invention is a weak acid system that does not react with the thermal shielding material and its oxide layer, thereby preventing it from affecting or damaging the oxide layer.
[0038] The thermal protection material targeted by the present invention is high temperature resistant MCrAlY, NiAl, NiPtAl or Al-infiltrated coating material, whose oxide layer is mainly Al2O3 layer or a mixture containing a small amount of NiO, NiAl2O4, Cr2O3, NiCr2O4 and other oxides.
[0039] The method provided by the present invention can be used to obtain a protective layer in which a metal conductive layer and a nickel metal layer are sequentially formed on the oxide layer of a thermal protection material. This structure is beneficial to protecting the integrity of the oxide film. The presence of the metal conductive layer + nickel film on the surface of the oxide layer effectively avoids damage to the oxide layer of the thermal protection material during the grinding and polishing process; at the same time, the metal conductive layer + nickel metal layer has no negative impact on the oxide layer and the thermal protection material, which is beneficial to subsequent research on the microscopic morphology of the oxide layer of the thermal protection material.
[0040] Therefore, the present invention can also provide a protective layer formed on the surface of the oxide layer of the thermal protection material, wherein the protective layer includes an inert metal conductive layer and a nickel metal layer.
[0041] At the same time, the present invention can also provide an application of the above protective layer structure in the microstructure research of the oxide layer of the thermal protection material.
[0042] The features and performance of the present invention are further described in detail below with reference to the embodiments.
[0043] Example 1 This embodiment provides a method for preparing a protective layer on an oxide layer of a thermal protection material, comprising the following steps: Step (1): Prepare the plating solution A certain amount of deionized water is placed in a container, nickel chloride hexahydrate, nickel sulfate hexahydrate, and a pH buffer solution are sequentially added thereto while stirring, and then the volume is fixed with deionized water to obtain a plating solution; The solution contains 0.05 mol / L nickel chloride hexahydrate, 0.05 mol / L nickel sulfate hexahydrate, and 0.1 mol / L phosphate buffer; Step (2) Pretreatment of plated parts The thermal protection material with oxide layer is placed in the ion sputtering chamber and vacuumed to 10 -3 Pa, vacuum sputter gold for 60 s, remove and set aside. Among them, the thermal protection material is MCrAlY, NiAl, NiPtAl or Al-infiltrated coating material, and the material of the oxide layer is mainly Al2O3, with a small amount of mixed oxides such as NiO, Cr2O3, NiAl2O4, NiCr2O4, etc.
[0044] The surface morphology after pretreatment was observed by SEM. Figure 1 As shown, the surface morphology of the oxide layer of the protective coating is normal and clearly visible, without abnormal bright areas or halos, indicating that the conductive layer on the surface oxide layer of the thermal protection material is complete and continuous.
[0045] Step (3) Preparation of Ni film The Ni film was prepared by constant potential deposition using an MD-30 electrochemical workstation. The conductive layer pretreated in step (2) was used as the cathode and the nickel mesh or nickel plate was used as the anode. The nickel film was electroplated in the prepared plating solution. The temperature was maintained at 20 °C during the electroplating process. The electroplating time was 2000 s and the current density was 20 mA / cm 2 The desired Ni layer can be prepared.
[0046] Example 2 This embodiment provides a method for preparing a protective layer on an oxide layer of a thermal protection material, comprising the following steps: Step (1): Prepare the plating solution A certain amount of deionized water is placed in a container, nickel chloride hexahydrate, nickel sulfate hexahydrate, and a pH buffer solution are sequentially added thereto while stirring, and then the volume is fixed with deionized water to obtain a plating solution; The solution contains 1.0 mol / L nickel chloride hexahydrate, 0.1 mol / L nickel sulfate hexahydrate, and 0.2 mol / L phosphate buffer; Step (2): Pretreatment of plated parts The thermal protection material with oxide layer is placed in the ion sputtering chamber and vacuumed to 10 -3 Pa, vacuum sputter gold for 90 s, and take it out for use.
[0047] Step (3): Preparation of Ni film The Ni film was prepared by constant potential deposition using an MD-30 electrochemical workstation. The conductive layer pretreated in step (2) was used as the cathode and the nickel mesh or nickel plate was used as the anode. The nickel film was electroplated in the prepared plating solution. The temperature was maintained at 20 °C during the electroplating process. The electroplating time was 600 s and the current density was 40 mA / cm 2 The desired Ni layer can be prepared.
[0048] The cross-sectional morphology of the thermal protection material prepared in this embodiment was observed by SEM scanning. Figure 2 As shown, the cross section of the oxide layer is flat, uniform and smooth, and the Ni layer can provide protection for the oxide layer.
[0049] Example 3 This embodiment provides a method for preparing a protective layer on an oxide layer of a thermal protection material, comprising the following steps: Step (1): Prepare the plating solution A certain amount of deionized water is placed in a container, nickel chloride hexahydrate, nickel sulfate hexahydrate, and a pH buffer solution are sequentially added thereto while stirring, and then the volume is fixed with deionized water to obtain a plating solution; The solution contains 1.2 mol / L nickel chloride hexahydrate, 0.15 mol / L nickel sulfate hexahydrate, and 0.5 mol / L phosphate buffer; Step (2): Pretreatment of plated parts The thermal protection material with oxide layer is placed in the ion sputtering chamber and vacuumed to 10 -3 Pa, vacuum sputter gold for 90 s, and take it out for use.
[0050] Step (3): Preparation of Ni film The Ni film was prepared by constant potential deposition using an MD-30 electrochemical workstation. The conductive layer pretreated in step (2) was used as the cathode and the nickel mesh or nickel plate was used as the anode. The nickel film was electroplated in the prepared plating solution. The temperature was maintained at 20 °C during the electroplating process. The electroplating time was 1200 s and the current density was 60 mA / cm 2 The desired Ni layer can be prepared.
[0051] The cross-sectional morphology of the thermal protection material prepared in this embodiment was observed by SEM scanning. Figure 3 As shown in FIG, the oxide layer at the cross section is intact when observed under SEM, and the Ni layer can effectively protect the oxide layer.
[0052] Comparative Example 1 The difference between this comparative example and Example 2 is that after the thermal protection material is oxidized, no metal conductive layer is prepared on the surface of the oxide layer, and no Ni protective layer is electroplated.
[0053] After the cross section is ground and polished, the morphology of the oxidized cross section is observed using a scanning electron microscope. The cross section morphology is as follows: Figure 4 shown.
[0054] from Figure 4 It can be seen that the oxide layer cracked and damaged, resulting in the failure to observe the true morphology and structure of the oxide layer during the oxidation process during the SEM cross-sectional morphology analysis.
[0055] By comparing the SEM cross-sectional morphologies of Example 2 and Comparative Example 1, it can be seen that the Ni protective layer on the surface of the oxide layer can well protect the oxide layer.
[0056] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.
Claims
1. A method for preparing a protective layer on an oxide layer of a thermal protection material, characterized in that: include: An inert metal conductive layer is prepared on the surface of the oxide layer of the thermal protection material by an ion sputtering method, and then nickel is plated on the surface by a constant potential deposition method to obtain a nickel metal layer; The metal element of the metal conductive layer is selected from at least one of gold, platinum and copper.
2. The method according to claim 1, characterized in that The metal element of the inert metal conductive layer is gold.
3. The method according to claim 1, characterized in that The preparation method of the inert metal conductive layer comprises: placing a heat protection material with an oxide layer in a vacuum chamber of an ion sputtering apparatus for vacuuming, and then performing ion sputtering to obtain the inert metal conductive layer.
4. The method according to claim 3, characterized in that The vacuum degree of the ion sputtering environment is controlled at 10 -3 Below Pa, the sputtering time is 30~120s.
5. The method according to claim 1, wherein The method for preparing the nickel metal layer includes: placing the heat protection material prepared with the inert metal conductive layer into the electroplating solution, and using the obtained inert metal conductive layer as the cathode and the nickel mesh or nickel plate as the anode to electroplate a nickel film by constant potential deposition method.
6. The method according to claim 5, wherein The electroplating conditions are: current density 15~60 mA / cm 2 , electroplating time 10~60 min, electroplating temperature 10~50 ℃.
7. The method according to claim 1, characterized in that The electroplating solution comprises: 0.02-1.2 mol / L of nickel chloride hexahydrate, 0.02-0.15 mol / L of nickel sulfate hexahydrate, and 0.1-0.5 mol / L of a pH buffer.
8. The method according to claim 7, characterized in that The pH buffering agents include acetic acid, phosphoric acid and citric acid.
9. The protective layer of the thermal protection material oxide layer obtained by the method according to any one of claims 1 to 8, characterized in that: The protective layer includes an inert metal conductive layer and a nickel metal layer sequentially formed on the surface of the oxide layer.
10. Use of the protective layer according to claim 9 in the study of the microstructure of the oxide layer of thermal protection materials.