Preparation method of high-entropy rare earth zirconate thermal barrier coating material with pressure-sensitive fluorescent probe

Abstract

The invention relates to a high-entropy rare earth zirconate thermal barrier coating material with a pressure-sensitive fluorescent probe as well as a preparation method and performance of the high-entropy rare earth zirconate thermal barrier coating material. The chemical formula of the high-entropy rare earth zirconate thermal barrier coating material is (Y < 0.2 > La < 0.2 > Er < 0.2 > Yb < 0.2 > Dy < 0.2 >) 2Zr2O7. The simple solid-phase synthesis method is adopted, operation is easy and convenient, cost is low, and large-scale production is easy. As a thermal barrier coating material, the material has good performance, the hardness of the material at room temperature is about 10 GPa, the thermal expansion coefficient of the material at 30-1000 DEG C is 13.5 * 10 <-6 > K, and the thermal conductivity of the material at 1200 DEG C is 1.62 W.m <-1 >. K <-1 >. The material has high thermal stability, and no phase change is generated after the material is calcined at 1600 DEG C for 9 hours. According to the high-entropy rare earth zirconate thermal barrier coating material with the pressure-sensitive fluorescent probe, the central positions of light-emitting peaks at 560 nm and 677 nm excited by 514 nm laser are sensitive to pressure, the red shift coefficient and the pressure coefficient of the high-entropy rare earth zirconate thermal barrier coating material are 0.178 nm / GPa and 0.223 nm / GPa respectively, and the pressure and the red shift are in a linear relation.

Description

Technical Field

[0001] The present invention relates to the field of thermal barrier coating materials, and in particular to a high-entropy rare earth zirconate thermal barrier coating material with a pressure-sensitive fluorescent probe, a preparation method thereof, and optical sensing performance thereof. The chemical formula of the high-entropy thermal barrier coating material with a pressure-sensitive fluorescent probe is (Y 0.2 La 0.2 Er 0.2 Yb 0.2 Dy 0.2 ) 2 Zr 2 O 7 . Background Art

[0002] With the development of aerospace and aviation technology, the operating temperature requirements for hot end components are getting higher and higher, and the limit operating temperature of high-temperature alloys (such as nickel-based high-temperature alloys) has been reached. The operating temperature of some heat-bearing parts of civil aviation engines, such as combustion chambers, nozzles, blades, etc., has exceeded 1100°C, which is a temperature that most aviation engine alloy materials cannot serve for a long time. To solve this problem, thermal barrier coating materials came into being. By spraying a layer of granular metal or ceramic material on the substrate material, it is melted and evenly covered on the surface of the substrate to form a coating with heat insulation properties to resist the high temperature environment. However, the harsh service environment of hot end component materials has brought greater challenges to the selection of thermal barrier coating materials. During the service process, the impact of high-speed airflow and its inclusions, the corrosion caused by the marine atmosphere, and the oxidation in the high temperature environment require thermal barrier coating materials to have excellent comprehensive properties such as high melting point, low thermal conductivity, high stability, high hardness, and a thermal expansion coefficient matching the substrate material. Finding a thermal barrier coating material with excellent comprehensive performance has become the key to improving the service life of hot end components. In addition, for thermal barrier coatings, in addition to the performance of the material itself, monitoring the service condition of the material is also very important, which is an indispensable part of the rational use of the material. For hot end components in extreme service environments, even a small structural damage may cause very serious consequences. For this reason, the research and development of functional thermal barrier coating materials, especially the development of functional materials with non-destructive testing, has also received more and more attention in recent years.

[0003] In order to meet the functional requirements of thermal barrier coating materials, people have conducted research in many material fields. Yttria partially stabilized zirconium dioxide (YSZ) has become the most mature and widely used thermal barrier coating material to date due to its low thermal conductivity and relatively high toughness. However, it still has some defects in the process of use. When working for a long time at a temperature above 1200℃, the porosity of YSZ will gradually decrease, the thermal conductivity will increase, and the thermal insulation effect will weaken. In addition, in a high temperature environment, YSZ thermal barrier coating will segregate, and thermally grown oxides mainly containing aluminum oxides will be generated between the alloy substrate and the coating. The stress generated by the continuous expansion of the oxide layer will cause the coating to fall off. While studying methods to optimize its performance, scholars are also looking for new thermal barrier coating materials with better performance. High entropy materials have become a hot spot in current material research due to their unique properties. High configuration entropy brings high temperature stability. The lattice distortion caused by different atomic sizes in the high entropy phase can change the physical properties of the material such as thermal stability, thermal conductivity and hardness. The slow diffusion characteristics of high entropy materials are conducive to inhibiting segregation, and the unique "cocktail" effect brings unparalleled material performance designability. These characteristics of high entropy materials coincide with the increasingly stringent requirements for comprehensive material performance of thermal barrier coatings. On the other hand, with the introduction of rare earth ion fluorescent probes into the field of new thermal barrier coating material design, certain progress has been made in recent years in the non-destructive testing of the service conditions of thermal barrier coatings during service. According to the principle of rare earth ion luminescence, the subtle damage, temperature or stress changes in the coating can be characterized by the characteristic parameters of the fluorescence ion spectrum (peak shape, peak position and intensity, etc.) of the rare earth doped in the coating material. However, the research on high entropy thermal barrier coating materials with rare earth ion fluorescence sensing function is still blank.

[0004] The present invention combines high entropy thermal barrier coating materials with rare earth ion fluorescence sensing functions. 2 On the basis of the above, five elements, Y, Er, La, Yb, and Dy, were added and synthesized by a simple solid phase method (Y 0.2 La 0.2 Er 0.2 Yb 0.2 Dy 0.2 ) 2 Zr 2 O 7 This high entropy rare earth zirconate thermal barrier coating material with rare earth ion fluorescence pressure sensing function. Through the study of its performance, it was found that the material has excellent properties such as low thermal conductivity, high thermal stability, high hardness and high thermal expansion coefficient. 3+ The ions can be used as fluorescent probes. Part of their characteristic luminescence peak is sensitive to external pressure conditions. When the pressure changes, the corresponding luminescence peak will also change. It has good rare earth ion fluorescence pressure sensing function. Summary of the invention

[0005] The purpose of the present invention is to overcome the deficiencies of the prior art and research and to provide a method for preparing a high entropy rare earth zirconate thermal barrier coating material with a pressure-sensitive fluorescent probe.

[0006] To achieve the above object, the present invention is implemented through the following technical solutions:

[0007] The present invention provides a method for preparing a high-entropy rare earth zirconate thermal barrier coating material with a pressure-sensitive fluorescent probe. The chemical formula of the material is (Y 0.2 La 0.2 Er 0.2 Yb 0.2 Dy 0.2 ) 2 Zr 2 O 7 .

[0008] The high entropy rare earth zirconate thermal barrier coating material with a pressure-sensitive fluorescent probe is prepared by a simple solid phase synthesis reaction method, and the method comprises the following steps:

[0009] Step 1: Use high purity Y 2 O 3 , Er 2 O 3 ,La 2 O 3 , Yb 2 O 3 、Dy 2 O 3 、ZrO 2 As raw materials, according to its chemical formula (Y 0.2 La 0.2 Er 0.2 Yb 0.2 Dy 0.2 ) 2 Zr 2 O 7 Weigh the raw materials by molar ratio, where Y 2 O 3 , Er 2 O 3 ,La 2 O 3 , Yb 2 O 3 、Dy 2 O 3 Equal molar ratio, ZrO 2 The molar content is 5 times that of other ingredients;

[0010] Step 2: Place the raw materials in the molar ratio in step 1 in a ball mill, add alcohol, and grind them thoroughly at 900 rpm for 4 hours;

[0011] Step 3: Place the product obtained in step 2 in a forced air drying oven and dry it at 60° C. to obtain a uniformly mixed powder sample.

[0012] Step 4: Put the powder obtained in step 3 into a mortar and add alcohol and grind for 4 hours to obtain a powder sample with uniform particles.

[0013] Step 5: Put the powder obtained in step 4 into a grinding mold and press the powder sample into a thin billet with a diameter of 13 mm under a pressure of 8 MPa;

[0014] Step 6: Place the thin billet obtained in step 5 into a high-temperature box furnace, set the temperature to 1600°C, calcine for 3 hours, and then cool naturally to obtain a sample (Y 0.2 La 0.2 Er 0.2 Yb 0.2 Dy 0.2 ) 2 Zr 2 O 7 .

[0015] At present, no researchers have studied rare earth high entropy zirconates (Y 0.2 La 0.2 Er 0.2 Yb 0.2 Dy 0.2 ) 2 Zr 2 O 7 The preparation process and performance of the thermal barrier coating are studied, and the present invention will fill the gap in this area. At the same time, the present invention has good performance as a thermal barrier coating material. The hardness of the material at room temperature is 10GPa, and the thermal expansion coefficient is 13.5×10 -6 K, at 1200°C, has 1.62 W·m -1 ·K -1 The material has high thermal stability and no phase change occurs after calcination at 1600℃ for 9h. 3+ The center position of the luminescence peaks at 560 and 677 nm excited by 514 nm laser of the high entropy rare earth zirconate thermal barrier coating material of the pressure sensitive fluorescent probe is sensitive to pressure, and its red shift is linearly related to pressure, with pressure coefficients of 0.178 nm / GPa and 0.223 nm / GPa respectively. Description of the drawings:

[0016] Figure 1 It is a high entropy rare earth zirconate thermal barrier coating material (Y 0.2 La 0.2 Er 0.2 Yb 0.2 Dy 0.2 )2 Zr 2 O 7 XRD and Raman spectra. (a) is the XRD spectra of samples prepared by calcination at different temperatures, and the diffraction peaks of the impurity phase are marked with red diamonds. (b) is the Raman spectrum of the high entropy rare earth zirconate thermal barrier coating material excited by 514nm laser. (c) is the XRD spectrum of the high entropy rare earth zirconate thermal barrier coating material after calcination at 1600℃ for different times.

[0017] Figure 2 It is a high entropy rare earth zirconate thermal barrier coating material (Y 0.2 La 0.2 Er 0.2 Yb 0.2 Dy 0.2 ) 2 Zr 2 O 7 The SEM spectrum shows that the pores of the material are evenly distributed.

[0018] Figure 3 It is a high entropy rare earth zirconate thermal barrier coating material (Y 0.2 La 0.2 Er 0.2 Yb 0.2 Dy 0.2 ) 2 Zr 2 O 7 EDS spectrum of .

[0019] Figure 4 It is a high entropy rare earth zirconate thermal barrier coating material (Y 0.2 La 0.2 Er 0.2 Yb 0.2 Dy 0.2 ) 2 Zr 2 O 7 Full scan XPS spectrum of .

[0020] Figure 5 It is a high entropy zirconium rare earth salt thermal barrier coating material (Y 0.2 La 0.2 Er 0.2 Yb 0.2 Dy 0.2 ) 2 Zr 2 O 7 Linear thermal expansion coefficient curve, the inserted image is an optical photograph of the surface indentation of the high entropy zirconium rare earth salt thermal barrier coating material used for Vickers hardness measurement.

[0021] Figure 6 It is a high entropy rare earth zirconate thermal barrier coating material (Y0.2 La 0.2 Er 0.2 Yb 0.2 Dy 0.2 ) 2 Zr 2 O 7 The evolution of the luminescence spectrum and the center position of the emitted light with pressure. 0.2 La 0.2 Er 0.2 Yb 0.2 Dy 0.2 ) 2 Zr 2 O 7 The photoluminescence spectrum of (Y 0.2 La 0.2 Er 0.2 Yb 0.2 Dy 0.2 ) 2 Zr 2 O 7 Photoluminescence spectra at different pressures; pressure evolution at the center of 560 nm.

[0022] Figure 7 (a), (b), (c) and (d) are high entropy rare earth zirconate thermal barrier coating materials (Y 0.2 La 0.2 Er 0.2 Yb 0.2 Dy 0.2 ) 2 Zr 2 O 7 The emission peaks at 560nm and 677nm are plotted against pressure. Specific implementation method:

[0023] The present invention is now further described in conjunction with specific implementation examples:

[0024] Preparation (Y 0.2 La 0.2 Er 0.2 Yb 0.2 Dy 0.2 ) 2 Zr 2 O 7 , and its preparation method is as follows:

[0025] High purity Y 2 O 3 , Er 2 O 3 ,La 2 O 3 , Yb 2 O3 、Dy 2 O 3 、ZrO 2 As raw materials, use an electronic balance to weigh the raw material reagents corresponding to each proportion of samples. Place the powder in a ball mill and add alcohol, grind it thoroughly at 900rpm for 5h, place the mixed product in a blast drying oven, and dry it at 80℃ overnight. Put the powder obtained after drying in a mortar and add alcohol to grind for 4h. Press the obtained powder sample into a thin billet with a diameter of 13mm under a pressure of 8MPa, place it in a high-temperature box furnace, set the temperature to 1600℃, calcine for 3h, and then cool it naturally.

[0026] Figure 1 It is a high entropy rare earth zirconate thermal barrier coating material (Y 0.2 La 0.2 Er 0.2 Yb 0.2 Dy 0.2 ) 2 Zr 2 O 7 From the XRD and Raman spectra, it can be seen that the material was calcined at 1600°C to obtain a sample with a single-phase component, and no phase change occurred after calcination at 1600°C for 9 hours, indicating that the material has high-temperature stability. Figure 2 It is a high entropy rare earth zirconate thermal barrier coating material (Y 0.2 La 0.2 Er 0.2 Yb 0.2 Dy 0.2 ) 2 Zr 2 O 7 From the SEM images, it can be seen that the material is well crystallized and the grains are uneven. In addition, some obvious pores are observed in the SEM images, and the pores are evenly distributed. Figure 3 Y 0.2 La 0.2 Er 0.2 Yb 0.2 Dy 0.2 ) 2 Zr 2 O 7 The EDS spectrum shows that the five rare earth elements (La, Dy, Er, Yb and Y) are evenly distributed on the sample surface, indicating that the sample is chemically uniform and forms a uniform solid solution. Figure 4 Y 0.2 La 0.2 Er 0.2 Yb 0.2 Dy 0.2 ) 2 Zr 2 O 7The full scan XPS spectrum of the samples confirmed the presence of O, Y, Er, La, Yb, Dy and Zr elements, which was consistent with the EDS results. Figure 5 It is a high entropy zirconium rare earth salt thermal barrier coating material (Y 0.2 La 0.2 Er 0.2 Yb 0.2 Dy 0.2 ) 2 Zr 2 O 7 The linear thermal expansion coefficient curve shows that the thermal expansion coefficient of the material is 13.5×10 -6 K. The inserted image is an optical photograph of the surface indentation of the high entropy zirconium rare earth oxide thermal barrier coating material used for Vickers hardness measurement. It can be seen that the indentation is uniform and the material hardness is calculated to be about 10GPa. Figure 6 It is a high entropy rare earth zirconate thermal barrier coating material (Y 0.2 La 0.2 Er 0.2 Yb 0.2 Dy 0.2 ) 2 Zr 2 O 7 The luminescence spectrum and the evolution of the center position of the emitted light with pressure were studied. The influence of pressure on the photoluminescence properties of the sample was further studied with the help of high-pressure experimental technology. Figure 7 It is a high entropy rare earth zirconate thermal barrier coating material (Y 0.2 La 0.2 Er 0.2 Yb 0.2 Dy 0.2 ) 2 Zr 2 O 7 The emission peak positions at 560nm and 677nm and the curves of their photoluminescence intensity relative to pressure further revealed that the material has the ability to be a pressure-sensitive fluorescent probe.

Claims

1. A high entropy rare earth zirconate thermal barrier coating material with a pressure-sensitive fluorescent probe, the chemical formula of the material is (Y 0.2 La 0.2 Er 0.2 Yb 0.2 Dy 0.2 )2Zr2O7.

2. The method for preparing a high entropy rare earth zirconate thermal barrier coating material with a pressure-sensitive fluorescent probe according to claim 1, characterized in that: The (Y 0.2 La 0.2 Er 0.2 Yb 0.2 Dy 0.2 )2Zr2O7 high entropy zirconate thermal barrier coating material is prepared by solid phase synthesis, and the method comprises the following steps: Step 1: Use high-purity Y2O3, Er2O3, La2O3, Yb2O3, Dy2O3, ZrO2 as raw materials, according to their chemical formula (Y 0.2 La 0.2 Er 0.2 Yb 0.2 Dy 0.2 )2Zr2O7 molar ratio Weigh the raw materials, among which Y2O3, Er2O3, La2O3, Yb2O3, Dy2O3 have the same molar ratio, and the molar content of ZrO2 is 5 times that of other components; Step 2: Place the raw materials in the molar ratio in step 1 in a ball mill, add alcohol, and grind them thoroughly at 900 rpm for 4 hours; Step 3: Place the product obtained in step 2 in a forced air drying oven and dry it at 60° C. to obtain a uniformly mixed powder sample. Step 4: Put the powder obtained in step 3 into a mortar and add alcohol and grind for 4 hours to obtain a powder sample with uniform particles. Step 5: Put the powder obtained in step 4 into a grinding mold and press the powder sample into a thin billet with a diameter of 13 mm under a pressure of 8 MPa; Step 6: Place the thin billet obtained in step 5 into a high-temperature box furnace, set the temperature to 1600°C, calcine for 3 hours, and then cool naturally to obtain a sample (Y 0.2 La 0.2 Er 0.2 Yb 0.2 Dy 0.2 )2Zr2O7.

3. The method for preparing a high entropy rare earth zirconate thermal barrier coating material with a pressure-sensitive fluorescent probe as claimed in claim 2, characterized in that: In step 1, the chemical formula (Y 0.2 La 0.2 Er 0.2 Yb 0.2 Dy 0.2 )2Zr2O7 molar ratio is weighed.

4. The method for preparing a high entropy rare earth zirconate thermal barrier coating material with a pressure sensitive fluorescent probe as claimed in claim 2, characterized in that: The raw materials in step 2 were placed in a ball mill, alcohol was added, and the mixture was fully ground at 900 rpm for 4 h.

5. The method for preparing a high entropy rare earth zirconate thermal barrier coating material with a pressure sensitive fluorescent probe as claimed in claim 2, characterized in that: The product in step 3 is placed in a forced air drying oven and dried at 60°C.

6. The method for preparing a high entropy rare earth zirconate thermal barrier coating material with a pressure sensitive fluorescent probe as claimed in claim 2, characterized in that: The powder in step 4 was placed in a mortar and ground with alcohol for 4 h.

7. The method for preparing a high entropy rare earth zirconate thermal barrier coating material with a pressure sensitive fluorescent probe as claimed in claim 2, characterized in that: In step 5, the powder is pressed into a thin billet with a diameter of 13 mm under a pressure of 8 MPa.

8. The method for preparing a high entropy rare earth zirconate thermal barrier coating material with a pressure sensitive fluorescent probe as claimed in claim 2, characterized in that: The thin billet was placed in a high temperature box furnace, the temperature was set to 1600°C, and the calcination was maintained for 3 hours.

9. The method for preparing a high entropy rare earth zirconate thermal barrier coating material with a pressure sensitive fluorescent probe as claimed in claim 2, characterized in that: The final chemical composition of the material is (Y 0.2 La 0.2 Er 0.2 Yb 0.2 Dy 0.2 )2Zr2O7.

10. The method for preparing a high entropy rare earth zirconate thermal barrier coating material with a pressure sensitive fluorescent probe according to claim 1, characterized in that: Er 3+ as a fluorescent probe.

11. As claimed in claim 10 3+ As a fluorescent probe, it is characterized by Its photoluminescence peak is sensitive to pressure, and the peak position red-shifts as the pressure increases.

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