A method for preparing a high-density non-interconnected phosphor speckle coating on a three-dimensional surface

Abstract

The application discloses a preparation method of a three-dimensional surface high-density non-connected phosphor speckle coating, and relates to the technical field of temperature and strain synchronous measurement, and comprises the following steps: step one: a surface modifier is applied on the surface of a base material to form a low surface modification layer, so as to reduce the surface energy; step two: a water-based phosphor coating layer is sprayed on the modification layer, and the coating comprises a phosphor material and a binder; and step three: the sprayed phosphor coating layer is cured at high temperature to form an island-shaped phosphor speckle coating, the characteristic size of the non-connected island-shaped structure of the coating is 5 microns to 5 millimeters, the interval is 1 microns to 1 millimeter, and the coverage is greater than 70%. The application can induce the water-based phosphor coating to spontaneously form a dense random island-shaped structure through surface energy regulation. The prepared phosphor speckle surface has high coverage, can completely retain the temperature response characteristics of the phosphor material, and can effectively provide sufficient gray scale features for a digital image correlation method due to the randomness of the island-shaped speckle and the high contrast of the pattern, so that the strain measurement requirement can be met.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of temperature and strain synchronous measurement, and particularly relates to a preparation method of a three-dimensional surface high-density non-connected phosphor speckle coating. BACKGROUND

[0002] Three-dimensional temperature-strain synchronous measurement is a key technology for characterizing the behavior characteristics and safety performance of materials and components under complex working conditions, especially in high-temperature equipment such as gas turbines and aero-engines. The running environment of the equipment has extreme characteristics such as high temperature, high pressure and strong corrosion, and the temperature and strain are highly coupled. Therefore, a precise synchronous measurement method is urgently needed to provide data support for equipment operation monitoring and performance evaluation. The existing technology faces the following problems:

[0003] Traditional contact temperature-strain measurement technology can only realize point measurement. In complex scenes such as high temperature and rotation, the contact point is easy to quickly age, resulting in a decrease in measurement accuracy and a shortening of service life, and it is difficult to adapt to harsh environments such as strong corrosion.

[0004] Although the combination of infrared temperature measurement and digital image correlation method (DIC) can realize strain measurement, the infrared temperature measurement accuracy is easily disturbed by background radiation, the target emissivity needs to be known, and the zenith angle has a significant influence on the measurement accuracy of inclined or long-distance surfaces, especially for large-curvature three-dimensional surfaces. In addition, the time and spatial resolution of the infrared camera is much lower than that of the ordinary camera, which limits the time and spatial accuracy of the measurement.

[0005] In order to overcome the above problems, the phosphor temperature measurement (PT) and the digital image correlation method (DIC) are combined to provide a key method for realizing temperature-strain synchronous measurement in complex environments. The temperature measurement technology based on the phosphor characteristics can realize high-precision measurement of the full-field temperature. Through the change of the luminescence intensity or the lifetime of the phosphor material, the temperature distribution of the surface to be measured can be directly reflected. The digital image correlation technology is a mature non-contact measurement method, which can accurately obtain full-field displacement and strain information by tracking the gray level change of the surface speckle, and is especially suitable for three-dimensional topography reconstruction and deformation analysis of complex surfaces. The combination of phosphor temperature measurement and digital image correlation method can break through the limitations of harsh environments and realize the synchronous measurement of three-dimensional temperature and strain information of complex structures in harsh environments.

[0006] However, the collaborative application of phosphor temperature measurement (PT) and digital image correlation (DIC) still has technical obstacles. PT relies on the phosphor characteristics of the overall coating to realize full-field temperature measurement, while DIC needs to rely on the gray level characteristics of sparse speckles to calculate strain. If the phosphor material is made into a speckle, the temperature measurement will not be complete due to insufficient signal coverage. If the overall coating is reserved, there is a lack of gray level difference required by DIC, which leads to a significant decrease in strain measurement accuracy. The technical conflict between the two restricts the application of synchronous measurement in high-temperature environments.

[0007] Further, the patent CN110926356B discloses a spraying method that depends on the characteristics of iron aluminum spinel, which is only applicable to shaped refractory materials, and has limited applicability to complex curved surfaces and other materials; the patent CN110793453A discloses a mask method with a complex process, which requires a pre-prepared two-dimensional template, and the use of laser engraving to prepare the template leads to low speckle density, and the template is difficult to fit and cannot be developed into a two-dimensional plane on a three-dimensional surface, which has poor adaptability to unknown three-dimensional surfaces; the patent CN115872742B relies on manual dropping in a dot coating method, which has low efficiency and cannot accurately control the size, spacing and density of the speckles, and is not suitable for large-area sample preparation.

[0008] Therefore, the prior art cannot realize the preparation of phosphor speckles with high coverage and non-connected characteristics on a three-dimensional surface, and cannot simultaneously meet the needs of PT full-field temperature measurement and DIC full-field strain measurement. Therefore, we propose a preparation method of a high-density non-connected phosphor speckle coating on a three-dimensional surface to solve the problems raised in the background. SUMMARY

[0009] The purpose of the present application is to provide a preparation method of a high-density non-connected phosphor speckle coating on a three-dimensional surface to solve the problem that it is difficult to prepare phosphor speckles with high coverage and non-connected characteristics on a three-dimensional surface in the current technology, thereby failing to simultaneously meet the needs of PT full-field temperature measurement and DIC full-field strain measurement.

[0010] To achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0011] A preparation method of a high-density non-connected phosphor speckle coating on a three-dimensional surface, comprising the following steps:

[0012] Step one: applying a surface modifier on the surface of the substrate to form a low surface modification layer to reduce the surface energy;

[0013] Step two: spraying a water-based phosphor coating layer on the modified layer, the coating layer comprising a phosphor material and a binder;

[0014] Step three: curing the sprayed phosphor coating layer by high temperature to form an island-shaped phosphor speckle coating, the characteristic size of the non-connected island-shaped structure being 5 μm-5 mm, the spacing being 1 μm-1 mm, and the coverage being greater than 70%.

[0015] The phosphor coating layer synchronously responds to temperature and strain, and is used for temperature-strain coupling measurement in a high-temperature environment or temperature-strain synchronous measurement in a dynamic deformation process.

[0016] Preferably, in step one, the substrate material is a metal material, an inorganic non-metal material or a composite material, and the substrate is a three-dimensional curved surface.

[0017] Preferably, in step one, the surface modifier includes one or more mixtures of fluorine-containing surfactants, organosilicon compounds, fluorine-containing polymer solutions, and hydrocarbon-based low-surface-energy substances.

[0018] Preferably, in step one, the surface modifier includes one or more mixtures of fluorine-containing surfactants, organosilicon compounds, fluorine-containing polymer solutions, and hydrocarbon-based low-surface-energy substances.

[0019] Preferably, in step two, the mass ratio of the phosphor material to the binder is 1:1-10, the phosphor material includes one of Mg4FGeO6:Mn, Y2O3:Eu, YAG:Dy, YSZ:Eu, Y2O3:Dy, and ZnO:Zn, and the phosphor material has a particle size of 0.5-50 μm.

[0020] Preferably, in step two, the coating thickness is 1-200 μm, and in step three, the curing temperature is 80-200 °C.

[0021] Preferably, the size and coverage of the island structure are achieved by adjusting the type of surface modifier, the spraying pressure, the nozzle diameter, and the spraying distance, and the ratio of the phosphor material to the binder.

[0022] Compared with the prior art, the present application has the following advantages:

[0023] The present application can induce water-based phosphor coating to spontaneously form a dense random island structure by surface energy regulation. The phosphor speckle surface prepared in this way has high coverage, can completely retain the temperature response characteristics of the phosphor material, and can effectively provide sufficient gray scale features for digital image correlation method due to the randomness of the island speckle and the high contrast of the pattern, thereby meeting the strain measurement requirements.

[0024] In addition, the inhibition of the low-surface-energy modified surface to the spreading of the coating, combined with the independent stable state formed between the droplets due to the difference in surface tension, lays a solid foundation for the precise regulation of the speckle structure. The present application has the advantages of simple preparation process, low cost, and suitability for any three-dimensional geometric surface, and has good applicability in temperature-strain coupling measurement in high-temperature environments.

[0025] The above summary is intended to illustrate only and is not intended to limit in any way. In addition to the illustrative aspects, embodiments and features described above, further aspects, embodiments and features will become apparent to those skilled in the art upon consideration of the drawings and the following detailed description. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 The present application is a coating preparation process diagram.

[0027] Figure 2 The present application is a phosphor speckle physical diagram under excitation.

[0028] Figure 3 These are examples of speckle patterns of different densities achieved by controlling parameters according to the present invention. Among them: (a) is Example 1; (b) is Example 2; (c) is Example 3.

[0029] Figure 4 The three-dimensional surface temperature-strain results are obtained through existing phosphorescent speckle measurements. Wherein: (a) is the three-dimensional temperature field; (b) is the three-dimensional strain field. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] Example 1

[0032] Material preparation: Silicone oil was selected as the surface modifier, Mg4FGeO6:Mn (MFG) with a particle size of 0.5-50μm was selected as the phosphorescent material, HPC (ZYP Coatings, USA) was selected as the binder, and the substrate sample was a 0.2mm thick 304 stainless steel sheet.

[0033] Preparation of phosphorescent coating: Mix MFG powder, HPC and deionized water in a mass ratio of 1:3:2, stir thoroughly and ultrasonically vibrate for 1 hour until homogeneous.

[0034] As attached Figure 1 , 2 The preparation steps of the phosphorescent speckle coating are shown below:

[0035] 1. Clean the surface of the substrate sample sequentially with distilled water and anhydrous ethanol, and then dry it thoroughly;

[0036] 2. Apply silicone oil evenly to the surface of the substrate sample using the wiping method for modification, and let it stand for 30 minutes to allow the surface modifier to fully bond with the substrate sample;

[0037] 3. Use an airbrush to evenly spray the phosphorescent coating onto the surface of the substrate sample. The airbrush diameter is 0.5 mm, the spraying pressure is 0.4 MPa, and the distance between the airbrush and the sample is 50 cm.

[0038] 4. Place the substrate sample in a drying oven at 80°C for 2 hours, and then cure it at 150°C for 5 hours to complete the coating preparation.

[0039] The coating thickness is 100μm, the average size of the island structure is 600μm, and the surface coverage is 75%.

[0040] Test: The bottom of the substrate sample piece was fixed, and the substrate sample was impacted from the oblique upper side using a 500°C hot jet. The results showed that the jet impact area had the highest temperature and strain, and the strain distribution was consistent with the temperature distribution, as shown in (a) of FIG. 1 and FIG. 2. Figure 2 Figure 4

[0041] Example Two

[0042] Material Preparation: The surface modifier was selected to be the same silicone oil as in Example One;

[0043] Phosphor Material: Y2O3:Eu was selected, and the particle size was 5-40 μm;

[0044] Binder: The same as in Example One, HPC (ZYP Coatings, USA) was selected;

[0045] Substrate Sample: The same as in Example One, a 304 stainless steel metal piece with a thickness of 0.2 mm.

[0046] Phosphor Coating Preparation: According to the same ratio as in Example One, Y2O3:Eu powder, HPC, and deionized water were mixed in a mass ratio of 1:3:1, and after sufficient stirring, ultrasonic oscillation was performed for 1 h to ensure uniform mixing and form a stable water-based phosphor coating.

[0047] Preparation Steps of Phosphor Speckle Coating:

[0048] 1. The substrate sample surface was cleaned with distilled water and anhydrous ethanol in sequence and dried thoroughly;

[0049] 2. The silicone oil was applied using a spraying method, and the surface modifier was allowed to fully combine with the substrate sample after standing for 30 min;

[0050] 3. The phosphor coating was uniformly sprayed on the substrate sample surface using a spray pen, the spray pen diameter was 0.5 mm, the spraying pressure was 0.4 MPa, and the distance between the spray pen and the sample was 30 cm;

[0051] 4. The sample was placed in a drying oven at 80°C for 2 hours, and then cured at 150°C for 5 h to complete the coating preparation.

[0052] The coating thickness was 200 μm, and the average size of the island structure was 300 μm. The test results are shown in (b) of FIG. 1 and FIG. 2. Figure 2

[0053] Example Three

[0054] ​​​Material preparation: the surface modifier is selected as polytetrafluoroethylene (PTFE) solution; the phosphor material is selected as YAG:Dy; the binder is the same as example one, selected as HPC (ZYP Coatings company, USA); the substrate sample is 6061 aluminum.

[0055] Phosphor coating preparation: according to the mass ratio of phosphor material to binder of 1:3, YAG:Dy powder, HPC and deionized water are mixed, stirred for 30 min, and then ultrasonically oscillated for 1.5 h to form a uniformly dispersed water-based phosphor coating.

[0056] Preparation steps of the phosphor speckle coating:

[0057] 1. The surface of the substrate sample is cleaned with distilled water and anhydrous ethanol in turn and dried thoroughly;

[0058] 2. The PTFE solution is sprayed by using a spray pen for surface modification;

[0059] 3. The phosphor coating is uniformly sprayed on the surface of the substrate sample by using a spray pen, the spray pen diameter is 0.5 mm, the spraying pressure is 0.5 MPa, and the distance between the spray pen and the sample is 30 cm;

[0060] 4. The substrate sample is placed in a drying oven at 80℃ for 2 hours, and then cured at 180℃ for 5 h to complete the coating preparation.

[0061] The coating thickness is 50 μm, and the average size of the island-shaped structure is 400 μm; the test results are shown in (c) of the accompanying drawings. Figure 2

[0062] The embodiments of the present application are given for example and description, although the embodiments of the present application have been shown and described above, it can be understood that the above-mentioned embodiments are exemplary, and cannot be understood as the limitation of the present application, the changes, modifications, replacements and variations of the above-mentioned embodiments made by the ordinary skilled in the art within the scope of the present application should be included in the protection scope of the present application.​

Claims

1. A method of producing a high density non-interconnecting phosphor speckle coating on a three-dimensional surface, characterized by, The method comprises the following steps: Step 1: applying a surface modifier on the surface of a substrate to form a low surface modification layer to reduce the surface energy; Step 2: spraying a water-based phosphor coating layer on the modification layer, the coating layer comprising a phosphor material and a binder; Step 3: curing the sprayed phosphor coating layer by high temperature to form an island-shaped phosphor speckle coating layer, the non-connected island-shaped structure having a characteristic size of 5 μm-5 mm, a pitch of 1 μm-1 mm, and a coverage of more than 70%; The phosphor coating layer synchronously responds to temperature and strain, and is used for temperature-strain coupling measurement in a high-temperature environment or synchronous measurement of temperature and strain in a dynamic deformation process.

2. The method of claim 1, wherein the method further comprises: In step 1, the substrate is a metal material, an inorganic non-metal material or a composite material, and the substrate is a three-dimensional curved surface.

3. The method of claim 1, wherein the method further comprises: applying a phosphor coating to the three-dimensional surface. In step 1, the surface modifier comprises one or more mixtures of fluorine-containing surfactants, organosilicon compounds, fluorine-containing polymer solutions and hydrocarbon-based low surface energy substances.

4. The method of claim 1, wherein the method further comprises: In step 1, the surface modifier is applied by one of rubbing, spraying, spin coating and dipping.

5. The method of claim 1, wherein the method further comprises: applying a phosphor coating to the non-interconnected phosphor coating. In step 2, the mass ratio of the phosphor material to the binder is 1:1-10, the phosphor material comprises one of Mg4FGeO6:Mn, Y2O3:Eu, YAG:Dy, YSZ:Eu, Y2O3:Dy and ZnO:Zn, and the particle size of the phosphor material is 0.5-50 μm.

6. The method of claim 1, wherein the method further comprises: In step 2, the coating layer has a thickness of 1-200 μm, and in step 3, the curing temperature is 80-200 ℃.

7. The method of claim 1, wherein the method further comprises: applying a phosphor coating to the non-interconnected phosphor coating. The size and coverage of the island-shaped structure are realized by adjusting the type of surface modifier, the spraying pressure, the nozzle diameter, the spraying distance, the ratio of phosphor material to binder and the like.

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