A thermal barrier coating material, a thermal barrier coating and a method of manufacturing and use thereof

Abstract

The application provides a thermal barrier coating material, a thermal barrier coating and a preparation method and application thereof. The composition general formula of the thermal barrier coating material is (Zr 1‑x Hf x ) 0.9 Y 0.1 O 1.95 wherein, 0

Description

Technical Field

[0001] This invention belongs to the field of thermal protective coating technology, and relates to a thermal barrier coating material, specifically a thermal barrier coating material, a thermal barrier coating, its preparation method and application. Background Technology

[0002] Thermal barrier coatings (TBCs) are a thermal protection technology that uses ceramic materials with low thermal conductivity and high stability at high temperatures to bond with a metal substrate as a coating. This effectively reduces the surface temperature of the metal substrate under high-temperature environments and significantly improves engine thermal efficiency. Its primary function is to provide insulation for high-temperature alloy hot components. Secondly, it also provides some degree of resistance to oxidation, corrosion, and erosion by foreign objects. Therefore, TBCs represent an important direction and approach for reducing the surface temperature of engine hot components to achieve higher turbine inlet gas temperatures, thereby improving engine performance and service life.

[0003] Currently, the most widely used thermal barrier coating material is yttrium-stabilized zirconia (YSZ) ceramic, which is generally prepared by atmospheric plasma spraying (APS) or electron beam physical vapor deposition (EB-PVD). YSZ coatings possess a thermodynamically non-equilibrium pseudo-tetragonal (t') phase structure. When the operating temperature exceeds 1200℃, this uniformly yttrium-containing t' phase decomposes into cubic (c) and tetragonal (t) phases, leading to reduced fracture toughness. During cooling, it also transforms into a monoclinic (m) phase, resulting in a 3-5% volume expansion, causing large-area cracking and peeling of the coating. Simultaneously, sintering causes a decrease in thermal insulation performance. These problems limit the use of YSZ coatings in high-temperature environments above 1200℃, making it difficult to meet the service requirements of high thrust-to-weight ratio aero-engines.

[0004] In addition, researchers also studied novel TBC materials such as rare-earth modified YSZ, rare-earth zirconates, rare-earth phosphate / cerium / tantalate, and high-entropy rare-earth ceramics. Compared to YSZ, rare-earth modified YSZ, due to the different stabilizing effects of various rare-earth oxide stabilizers, often results in a significant improvement in one property while sacrificing others. Furthermore, with the increase of doping elements, the complexity of the material's crystal structure increases, posing new challenges to the coating preparation process. Rare-earth zirconates have advantages such as low thermal conductivity, resistance to sintering, high-temperature phase structure stability, and good corrosion resistance, but their coefficient of thermal expansion is lower than that of YSZ, and due to the lack of phase transformation toughening and ferroelastic toughening mechanisms found in YSZ, their fracture toughness is relatively low. Rare-earth phosphate / cerium tantalate has excellent thermal insulation properties and a high coefficient of thermal expansion, but they have extremely high requirements for the stoichiometry of the material. The melting point of rare-earth phosphates decreases significantly with the segregation of their chemical components, and rare-earth cerium phosphates will decrease with the precipitation of Ce during cooling. 3+ To Ce 4+The transformation leads to huge thermal stress caused by thermal shrinkage, which seriously affects their applications in high-temperature working environments. High-entropy rare-earth ceramic materials have the high-entropy effect of thermodynamics, the lattice distortion effect of the structure, the kinetic hysteresis diffusion effect, and the synergistic effect of components. However, it is still unknown whether the components can artificially regulate the thermophysical properties of the coating and the role of the high-entropy effect under high-temperature corrosion.

[0005] Therefore, aiming at the deficiencies of the existing technology, it is necessary to provide a thermal barrier coating material, a thermal barrier coating, and its preparation method and application, which can retain the existence form of the t' phase of the traditional YSZ material and its excellent comprehensive mechanical properties, while improving its high-temperature resistance and thermophysical properties above 1200°C. Summary of the Invention

[0006] The purpose of the present invention is to provide a thermal barrier coating material, a thermal barrier coating, and its preparation method and application. The thermal barrier coating retains the excellent mechanical properties of YSZ, and has both high structural stability and low thermal conductivity.

[0007] To achieve the purpose of this invention, the following technical solutions are adopted:

[0008] In the first aspect, the present invention provides a thermal barrier coating material, and the general composition formula of the thermal barrier coating material is (Zr 1-x Hf x ) 0.9 Y 0.1 O 1.95 , where 0 < x ≤ 0.5.

[0009] The thermal barrier coating material provided by the present invention combines the characteristics of hafnium oxide having a high melting point and a high phase transition temperature. Zirconia and hafnium oxide form a continuous solid solution, which is a coating material of a non-thermodynamic equilibrium tetragonal phase of yttria-stabilized zirconia-hafnium oxide solid solution. The material has a single non-thermodynamic equilibrium tetragonal phase (t') structure similar to 8YSZ, retains the excellent mechanical properties of 8YSZ. The non-thermodynamic equilibrium tetragonal phase t' is a ferroelastic phase, and this ferroelastic phase has excellent fracture toughness, and has both high structural stability and low thermal conductivity, and improves the thermophysical properties of the material at 1600°C.

[0010] Among them, 0 < x ≤ 0.5, for example, it can be 0.1, 0.2, 0.3, 0.4 or 0.5, but is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0011] In the second aspect, the present invention provides a preparation method of the thermal barrier coating material as described in the first aspect, and the preparation method includes the following steps:

[0012] (1) Mix zirconium source, hafnium source and yttrium source to obtain a mixture;

[0013] (2) After mixing the precipitant with the mixture obtained in step (1), the mixture is calcined to obtain the thermal barrier coating material.

[0014] The preparation method provided by this invention synthesizes pure tetragonal yttrium oxide-stabilized zirconium oxide-hafnium oxide solid solution ceramic coating materials through homogeneous chemical coprecipitation-calcination. The process is simple and controllable, with high purity, low equipment requirements and low production costs, making it suitable for industrial applications.

[0015] Preferably, in the mixture described in step (1), the molar ratio of Zr, Hf, and Y, Zr:Hf:Y, is (4.5-8.1):(0.9-4.5):1, for example, it can be 6:3:1, 4.5:4.5:1, 8.1:0.9:1, 5:4:1, or 7:2:1, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0016] Preferably, the zirconium source in step (1) comprises a soluble zirconium salt.

[0017] Preferably, the zirconium source in step (1) includes ZrOCl2 and / or ZrCl4.

[0018] Preferably, the hafnium source in step (1) includes a soluble hafnium salt.

[0019] Preferably, the hafnium source in step (1) includes HfCl4 and / or HfOCl2.

[0020] Preferably, the yttrium source in step (1) includes yttrium oxides and / or soluble yttrium salts.

[0021] Preferably, the yttrium source in step (1) includes Y2O3 and / or Y(NO3)3.

[0022] Preferably, the precipitant in step (2) includes any one or a combination of at least two of ammonia, ammonium carbonate or ammonium bicarbonate. Typical but non-limiting combinations include a combination of ammonia and ammonium carbonate, a combination of ammonium carbonate and ammonium bicarbonate, a combination of ammonia and ammonium bicarbonate, or a combination of ammonia, ammonium carbonate and ammonium bicarbonate.

[0023] Preferably, the pH of the precipitant in step (2) is >13, for example, it can be 13.1, 13.2, 13.4, 13.5, 13.6, 13.8 or 14, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0024] Preferably, the calcination temperature in step (2) is 1000-1200℃, for example, it can be 1000℃, 1050℃, 1100℃, 1150℃ or 1200℃, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0025] Preferably, the calcination time in step (2) is 2-4 hours, for example, it can be 2 hours, 2.5 hours, 3 hours, 3.5 hours or 4 hours, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0026] Preferably, the mixture in step (2) is washed, dried, ground and sieved in sequence.

[0027] Preferably, the drying temperature is 60-80℃, for example, it can be 60℃, 65℃, 70℃, 75℃ or 80℃, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0028] Preferably, the drying time is 8-10 hours, for example, 8 hours, 8.5 hours, 9 hours, 9.5 hours or 10 hours, but not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0029] Preferably, the particle size of the sieved powder is ≤200 mesh, for example, it can be 200 mesh, 250 mesh, 300 mesh, 500 mesh, 700 mesh or 1000 mesh, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0030] Thirdly, the present invention provides a thermal barrier coating, which is prepared from the thermal barrier coating material described in the first aspect.

[0031] Fourthly, the present invention provides a method for preparing a thermal barrier coating, the method comprising the following steps:

[0032] (a) The thermal barrier coating material is mixed with a binder and a dispersant to obtain a spray powder;

[0033] (b) Atmospheric plasma spraying is performed using the spray powder obtained in step (a) to obtain a thermal barrier coating.

[0034] Preferably, the amount of adhesive used in step (a) is 5-8 wt% of the thermal barrier coating material, for example, it can be 5 wt%, 5.5 wt%, 6 wt%, 6.5 wt%, 7 wt%, 7.5 wt% or 8 wt%, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0035] Preferably, the mass of the dispersant in step (a) is 4-6 wt% of the thermal barrier coating material, for example, it can be 4 wt%, 4.5 wt%, 5 wt%, 5.5 wt% or 6 wt%, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0036] Preferably, the mixing in step (a) is followed by a second drying process.

[0037] Preferably, the second drying temperature is 60-70°C, for example, 60°C, 62°C, 64°C, 65°C, 66°C, 68°C or 70°C, but not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0038] Preferably, the second drying time is 15-20 minutes, for example, it can be 15 minutes, 16 minutes, 17 minutes, 18 minutes, 19 minutes or 20 minutes, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0039] Preferably, the particle size range of the sprayed powder in step (a) is 80-325 mesh, for example, it can be 80 mesh, 100 mesh, 200 mesh, 300 mesh or 325 mesh, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0040] Preferably, the flowability of the sprayed powder in step (a) is 25-60s / 50g, for example, it can be 25s / 50g, 30s / 50g, 40s / 50g, 50s / 50g or 60s / 50g, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0041] Preferably, the loose bulk density of the sprayed powder in step (a) is 2.0-3.0 g / cm³. 3 For example, it could be 2.0 g / cm³. 3 2.2g / cm 3 2.4g / cm 3 2.5g / cm 3 2.6g / cm 3 2.8g / cm 3 Or 3.0g / cm 3 However, this does not limit the listed values; other unlisted values ​​within the range are also applicable.

[0042] Preferably, the net power of atmospheric plasma spraying in step (b) is 30-50 kW, for example, it can be 30 kW, 35 kW, 40 kW, 45 kW or 50 kW, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0043] Preferably, the spray gun voltage for atmospheric plasma spraying in step (b) is 65-70V, for example, it can be 65V, 66V, 67V, 68V, 69V or 70V, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0044] Preferably, the spray gun current for atmospheric plasma spraying in step (b) is 500-550A, for example, it can be 500A, 510A, 520A, 530A, 540A or 550A, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0045] Preferably, the argon flow rate for atmospheric plasma spraying in step (b) is 30-40 L / min, for example, it can be 30 L / min, 32 L / min, 34 L / min, 35 L / min, 36 L / min, 38 L / min or 40 L / min, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0046] Preferably, the hydrogen flow rate for atmospheric plasma spraying in step (b) is 4-6 L / min, for example, it can be 4 L / min, 4.5 L / min, 5 L / min, 5.5 L / min or 6 L / min, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0047] Preferably, the powder feeding rate of atmospheric plasma spraying in step (b) is 25-40 g / min, for example, it can be 25 g / min, 28 g / min, 30 g / min, 32 g / min, 35 g / min, 38 g / min or 40 g / min, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0048] Preferably, the spraying distance of atmospheric plasma spraying in step (b) is 100-120mm, for example, it can be 100mm, 105mm, 110mm, 115mm or 120mm, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0049] Fifthly, the present invention provides an application of the thermal barrier coating as described in the third aspect, wherein the thermal barrier coating is applied to the protection of hot-end components of an aero-engine.

[0050] Compared with the prior art, the present invention has the following beneficial effects:

[0051] The thermal barrier coating material and thermal barrier coating provided by this invention have excellent mechanical properties and stable structure. They exhibit no weight loss or phase change from room temperature to 1600℃. Compared with the traditional 8YSZ coating, the coefficient of thermal expansion is not significantly different, and the thermal conductivity is 23-25% lower. The preparation method is simple and controllable, with high purity, low equipment requirements and low production costs, making it suitable for industrial applications. Attached Figure Description

[0052] Figure 1These are full-spectrum X-ray diffraction patterns of the thermal barrier coatings prepared in Examples 1-3 and Comparative Example 1 of this invention.

[0053] Figure 2 These are 72.5-75.5° micro-area X-ray step-scan diffraction patterns of the thermal barrier coatings prepared in Examples 1-3 and Comparative Example 1 of this invention.

[0054] Figure 3 This is a graph showing the relationship between the lattice parameters of the thermal barrier coatings prepared in Examples 1-3 and Comparative Example 1 of the present invention and the molar amount x of hafnium oxide.

[0055] Figure 4 This is a differential scanning thermogravimetric curve of the thermal barrier coating prepared in Example 1 of the present invention.

[0056] Figure 5 This is a differential scanning thermogravimetric curve of the thermal barrier coating prepared in Example 2 of the present invention.

[0057] Figure 6 This is a differential scanning thermogravimetric curve of the thermal barrier coating prepared in Example 3 of the present invention.

[0058] Figure 7 This is a graph showing the relationship between the thermal expansion coefficient and temperature of the thermal barrier coatings prepared in Examples 1-3 and Comparative Example 1 of the present invention.

[0059] Figure 8 These are curves showing the change in thermal conductivity of the thermal barrier coatings prepared in Examples 1-3 and Comparative Example 1 of the present invention as a function of temperature. Detailed Implementation

[0060] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0061] To clearly illustrate the technical solution of the present invention, the thermal barrier coating prepared in the embodiments of the present invention was subjected to phase analysis using an X-ray diffractometer (XRD). The 2θ range was 20-100°, and a slow micro-area scan was performed in the range of 72.5-75.5° to accurately characterize the phase structure of the coating. The thermogravimetric (TG) and differential thermal (DSC) information of the thermal barrier coating were measured using a simultaneous thermal analyzer to analyze the weight change of the coating at high temperature and potential physicochemical processes such as phase transformation and decomposition. The coating sheet was processed to a diameter of 12.7±0.2 mm and a thickness of 1±0.1 mm using a grinding machine. The thermal diffusivity of the coating was tested using a laser thermal conductivity meter, and the thermal conductivity of the coating was calculated by density and heat capacity.

[0062] Preparation Example 1

[0063] This preparation example provides a thermal barrier coating material, the composition of which is (Zr)0.9 Hf 0.1 ) 0.9 Y 0.1 O 1.95 .

[0064] The preparation method of the thermal barrier coating material includes the following steps:

[0065] (1) Based on the molar ratio of Zr:Hf:Y of 8.1:0.9:1 and the total metal ion concentration of 0.5mol / L, weigh 110.21g ZrOCl2·8H2O, 12.22g HfCl4 and 4.52g Y2O3 into a beaker, add 800mL of deionized water to the beaker and stir continuously until fully dissolved to obtain a mixture;

[0066] (2) The mixture obtained in step (1) is placed into a separatory funnel and dropped into a large beaker containing ammonia precipitant. The pH of the ammonia is 13.5 and the dropping rate is controlled at 1 drop / s. The reaction forms a white flocculent hydroxide precipitate. The precipitate is then vacuum filtered. During the filtration process, the precipitate is first washed repeatedly with deionized water to remove excess ammonia and impurity ions. When the pH of the clear liquid is 7-8, it is washed 2-3 times with anhydrous ethanol to obtain a gel-like hydroxide precipitate. The precipitate is placed in an oven at 80°C and dried for 10 hours. After the hydroxide precipitate is dried and ground, it is passed through a 200-mesh sieve. The obtained powder is placed in a muffle furnace and calcined at 1200°C for 2 hours. After cooling to room temperature, the thermal barrier coating material ceramic powder is obtained.

[0067] Preparation Example 2

[0068] This preparation example provides a thermal barrier coating material, the composition of which is (Zr) 0.7 Hf 0.3 ) 0.9 Y 0.1 O 1.95 .

[0069] The preparation method of the thermal barrier coating material is the same as that of Preparation Example 1. In step (1), the molar ratio of Zr:Hf:Y is 6.3:2.7:1 and the total metal ion concentration is 0.5 mol / L. 85.72 g ZrOCl2·8H2O, 36.52 g HfCl4 and 4.52 g Y2O3 are weighed. The rest are the same as in Preparation Example 1.

[0070] Preparation Example 3

[0071] This preparation example provides a thermal barrier coating material, the composition of which is (Zr) 0.5 Hf 0.5 ) 0.9 Y 0.1 O 1.95 .

[0072] The preparation method of the thermal barrier coating material is the same as that of Preparation Example 1. In step (1), the molar ratio of Zr:Hf:Y is 4.5:4.5:1 and the total metal ion concentration is 0.5 mol / L. 61.23 g of ZrOCl2·8H2O, 60.86 g of HfCl4 and 4.52 g of Y2O3 are weighed. The rest are the same as in Preparation Example 1.

[0073] Preparation Example 4

[0074] This preparation example provides a thermal barrier coating material, which has the same composition as that in Preparation Example 3.

[0075] The preparation method of the thermal barrier coating material includes the following steps:

[0076] (1) Based on the molar ratio of Zr:Hf:Y of 8.1:0.9:1 and the total metal ion concentration of 0.5mol / L, weigh 110.21g ZrOCl2·8H2O, 12.22g HfCl4 and 4.52g Y2O3 into a beaker, add 800mL of deionized water to the beaker and stir continuously until fully dissolved to obtain a mixture;

[0077] (2) The mixture obtained in step (1) is placed into a separatory funnel and dropped into a large beaker containing ammonia precipitant. The pH of the ammonia is 13.5 and the dropping rate is controlled at 1 drop / s. The reaction forms a white flocculent hydroxide precipitate. The precipitate is then vacuum filtered. During the filtration process, the precipitate is first washed repeatedly with deionized water to remove excess ammonia and impurity ions. When the pH of the clear liquid is 7-8, it is washed 2-3 times with anhydrous ethanol to obtain a gel-like hydroxide precipitate. The precipitate is placed in an oven at 70°C and dried for 9 hours. After the hydroxide precipitate is dried and ground, it is passed through a 200-mesh sieve. The obtained powder is placed in a muffle furnace and calcined at 1100°C for 3 hours. After cooling to room temperature, the ceramic powder of the thermal barrier coating material is obtained.

[0078] Preparation Example 5

[0079] This preparation example provides a thermal barrier coating material, which has the same composition as that in Preparation Example 3.

[0080] The preparation method of the thermal barrier coating material includes the following steps:

[0081] (1) Based on the molar ratio of Zr:Hf:Y of 8.1:0.9:1 and the total metal ion concentration of 0.5mol / L, weigh 110.21g ZrOCl2·8H2O, 12.22g HfCl4 and 4.52g Y2O3 into a beaker, add 800mL of deionized water to the beaker and stir continuously until fully dissolved to obtain a mixture;

[0082] (2) The mixture obtained in step (1) is placed into a separatory funnel and dropped into a large beaker containing ammonia precipitant. The pH of the ammonia is 13.5 and the dropping rate is controlled at 1 drop / s. The reaction forms a white flocculent hydroxide precipitate. The precipitate is then vacuum filtered. During the filtration process, the precipitate is first washed repeatedly with deionized water to remove excess ammonia and impurity ions. When the pH of the clear liquid is 7-8, it is washed 2-3 times with anhydrous ethanol to obtain a gel-like hydroxide precipitate. The precipitate is placed in an oven at 60°C and dried for 8 hours. After the hydroxide precipitate is dried and ground, it is passed through a 200-mesh sieve. The obtained powder is placed in a muffle furnace and calcined at 1000°C for 4 hours. After cooling to room temperature, the ceramic powder of the thermal barrier coating material is obtained.

[0083] Preparation Example 6

[0084] This preparation example provides a thermal barrier coating material, which has the same composition as that in Preparation Example 3.

[0085] The preparation method of the thermal barrier coating material is the same as that of Preparation Example 3, except that the pH of the ammonia water in step (2) is controlled to be 10.

[0086] Comparative Preparation Example 1

[0087] This comparative preparation example provides a thermal barrier coating material, the composition of which is Zr. 0.9 Y 0.1 O 1.95 .

[0088] The preparation method of the thermal barrier coating material is the same as that of Preparation Example 3, except that in step (1), ZrOCl2·8H2O and Y2O3 are weighed according to a molar ratio of Zr:Y of 9:1.

[0089] Comparative Preparation Example 2

[0090] This comparative preparation example provides a thermal barrier coating material, the composition of which is (Zr) 0.3 Hf 0.7 ) 0.9 Y 0.1 O 1.95 .

[0091] The preparation method of the thermal barrier coating material is the same as that of Preparation Example 3, except that in step (1), ZrOCl2·8H2O, HfCl4 and Y2O3 are weighed according to the molar ratio of Zr:Hf:Y of 2.7:6.3:1.

[0092] Example 1

[0093] This embodiment provides a thermal barrier coating, which is prepared from the thermal barrier coating material prepared in Preparation Example 1, and the composition of the thermal barrier coating is (Zr 0.9 Hf 0.1 ) 0.9 Y 0.1 O 1.95 .

[0094] The method for preparing the thermal barrier coating includes the following steps:

[0095] (a) Place the thermal barrier coating material ceramic powder in a beaker, add 6wt% binder and 4wt% dispersant, mix well, and then dry in an oven at 60°C for 15 minutes. Before the powder is completely dry, sieve it, retaining 80-325 mesh suitable for plasma spraying. The flowability of the spraying powder is tested using the standard funnel method (Hall flow meter) and is 36.99 s / 50 g, with a loose density of 2.16 g / cm³. 3 ;

[0096] (b) The substrate for spraying is a graphite sheet with a diameter of 12.7±0.1mm, which facilitates the removal of the coating and allows for thermal conductivity testing. The surface of the substrate to be sprayed is sandblasted with No. 60 brown corundum sand at a sandblasting pressure of 0.3MPa and an angle of 75°. The parameters of the atmospheric plasma spraying equipment are adjusted as follows: spraying distance 115mm, spray gun voltage 68V, spray gun current 520A, powder feed rate 28g / min, argon flow rate 35L / min, hydrogen flow rate 5L / min, and 45 spray passes. After cooling, a thermal barrier coating is obtained.

[0097] The X-ray diffraction pattern, the relationship between lattice parameters and the molar amount of hafnium oxide x, the differential scanning thermogravimetric curve, the relationship between the coefficient of thermal expansion and temperature, and the curve of thermal conductivity versus temperature of the thermal barrier coating prepared in this embodiment are shown below. Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 7 and Figure 8 As shown.

[0098] Example 2

[0099] This embodiment provides a thermal barrier coating, which is prepared from the thermal barrier coating material prepared in Preparation Example 2. The composition of the thermal barrier coating is (Zr 0.7 Hf 0.3 ) 0.9 Y 0.1 O 1.95 .

[0100] The preparation method of the thermal barrier coating is the same as that in Example 1.

[0101] The X-ray diffraction pattern, the relationship between lattice parameters and the molar amount of hafnium oxide x, the differential scanning thermogravimetric curve, the relationship between the coefficient of thermal expansion and temperature, and the curve of thermal conductivity versus temperature of the thermal barrier coating prepared in this embodiment are shown below. Figure 1 , Figure 2 , Figure 3 , Figure 5 , Figure 7 and Figure 8 As shown.

[0102] Example 3

[0103] This embodiment provides a thermal barrier coating, which is prepared from the thermal barrier coating material prepared in Preparation Example 3. The composition of the thermal barrier coating is (Zr 0.5 Hf 0.5 ) 0.9 Y 0.1 O 1.95 .

[0104] The preparation method of the thermal barrier coating is the same as that in Example 1.

[0105] The X-ray diffraction pattern, the relationship between lattice parameters and the molar amount of hafnium oxide x, the differential scanning thermogravimetric curve, the relationship between the coefficient of thermal expansion and temperature, and the curve of thermal conductivity versus temperature of the thermal barrier coating prepared in this embodiment are shown below. Figure 1 , Figure 2 , Figure 3 , Figure 6 , Figure 7 and Figure 8 As shown.

[0106] Example 4

[0107] This embodiment provides a thermal barrier coating, which is prepared from the thermal barrier coating material prepared in Preparation Example 4.

[0108] The method for preparing the thermal barrier coating includes the following steps:

[0109] (a) Place the thermal barrier coating material ceramic powder in a beaker, add 5 wt% binder and 5 wt% dispersant, mix well, and then dry in an oven at 65°C for 18 min. Before the powder is completely dry, sieve it, retaining 80-325 mesh suitable for plasma spraying. The flowability of the spraying powder is tested using the standard funnel method (Hall flow meter), which shows 25 s / 50 g, and the loose density is 2.0 g / cm³. 3 ;

[0110] (b) The substrate to be sprayed is a graphite sheet with a diameter of 12.7±0.1mm. The surface of the substrate to be sprayed is sandblasted with No. 60 brown corundum sand. The sandblasting pressure is 0.35MPa and the angle is 80°. The parameters of the atmospheric plasma spraying equipment are adjusted as follows: spraying distance 100mm, spray gun voltage 65V, spray gun current 500A, powder feed rate 25g / min, argon flow rate 30L / min, hydrogen flow rate 4L / min, and the number of spraying passes is 40. After the spraying is completed and cooled, a thermal barrier coating is obtained.

[0111] Example 5

[0112] This embodiment provides a thermal barrier coating, which is prepared from the thermal barrier coating material prepared in Preparation Example 5.

[0113] The method for preparing the thermal barrier coating includes the following steps:

[0114] (a) Place the thermal barrier coating material ceramic powder in a beaker, add 8 wt% binder and 6 wt% dispersant, mix well, and then dry in an oven at 65°C for 18 min. Before the powder is completely dry, sieve it, retaining 80-325 mesh suitable for plasma spraying. The flowability of the spraying powder is tested using the standard funnel method (Hall flow meter), which shows 60 s / 50 g, and the loose density is 3.0 g / cm³. 3 ;

[0115] (b) The substrate for spraying is a graphite sheet with a diameter of 12.7±0.1mm. The surface of the substrate to be sprayed is sandblasted with No. 60 brown corundum sand at a sandblasting pressure of 0.4MPa and an angle of 90°. The parameters of the atmospheric plasma spraying equipment are adjusted as follows: spraying distance 120mm, spray gun voltage 70V, spray gun current 550A, powder feed rate 40g / min, argon flow rate 40L / min, hydrogen flow rate 6L / min, and 50 spray passes. After cooling after spraying, a thermal barrier coating is obtained.

[0116] Example 6

[0117] This embodiment provides a thermal barrier coating, which is prepared from the thermal barrier coating material prepared in Preparation Example 6.

[0118] Example 7

[0119] This embodiment provides a thermal barrier coating, which is prepared from the thermal barrier coating material prepared in Preparation Example 3.

[0120] The preparation method of the thermal barrier coating is the same as that in Example 1, except that the amount of binder in step (a) is 3 wt% and the amount of dispersant is 2 wt%.

[0121] Example 8

[0122] This embodiment provides a thermal barrier coating, which is prepared from the thermal barrier coating material prepared in Preparation Example 3.

[0123] The preparation method of the thermal barrier coating is the same as that in Example 1, except that the amount of binder in step (a) is 10 wt% and the amount of dispersant is 8 wt%.

[0124] Comparative Example 1

[0125] This comparative example provides a thermal barrier coating prepared from the thermal barrier coating material prepared in Comparative Preparation Example 1, wherein the thermal barrier coating has a composition of Zr. 0.9 Y 0.1 O 1.95 .

[0126] The preparation method of the thermal barrier coating is the same as that in Example 1, ZrOCl2·8H2O and Y2O3 are weighed according to the molar ratio of Zr:Y of 9:1 in step (1), and the rest are the same as in Example 1.

[0127] The X-ray diffraction pattern, lattice parameter versus hafnium oxide molar amount x, thermal expansion coefficient versus temperature, and thermal conductivity versus temperature curve of the thermal barrier coating (denoted as 8YSZ) prepared in this comparative example are shown below. Figure 1 , Figure 2 , Figure 3 , Figure 7 and Figure 8 As shown.

[0128] Comparative Example 2

[0129] This comparative example provides a thermal barrier coating prepared from the thermal barrier coating material prepared in Comparative Preparation Example 2. The composition of the thermal barrier coating is (Zr 0.3 Hf 0.7 ) 0.9 Y 0.1 O 1.95 .

[0130] The preparation method of the thermal barrier coating is the same as that in Example 1, ZrOCl2·8H2O, HfCl4 and Y2O3 are weighed according to the molar ratio of Zr:Hf:Y of 3:7:1 in step (1), and the rest are the same as in Example 1.

[0131] Table 1

[0132]

[0133]

[0134] The 8YSZ thermal barrier coating prepared in Comparative Example 1 has high purity, such as... Figure 1 The XRD diffraction pattern shown, when compared with the standard card, indicates that it is entirely composed of pseudo-tetragonal phase t'. Figure 1 It can be seen that the thermal barrier coating prepared by the method provided in this invention has a non-thermodynamically balanced t' pseudo-tetragonal phase. Compared with 8YSZ, the diffraction peak positions have shifted, indicating that the addition of hafnium oxide causes cell shrinkage. Figure 2 Further analysis confirmed that the phase composition of the solid solution ceramic coating was a pure t' phase, allowing for the acquisition of precise lattice parameters, such as... Figure 3 As shown, with the increase of hafnium oxide doping in 8YSZ, the lattice parameters of the formed zirconium oxide-hafnium oxide solid solution ceramic coating continuously decrease, and the tetragonality c / a... t’ The continuous increase indicates that the present invention utilizes Zr in the zirconium oxide lattice structure. 4+ Position doping Hf 4+ This causes a slight distortion in the crystal lattice structure, resulting in a decrease in the lattice constant and an increase in tetragonality, but does not affect the original 8YSZ phase structure.

[0135] Depend on Figure 4 , 5 As can be seen from Figure 6, the thermal barrier coating prepared by the present invention does not lose weight from room temperature to 1600°C, and no obvious endothermic / exothermic peaks are observed in the thermogravimetric curve, indicating that the coating does not undergo phase change or other physicochemical processes at high temperatures and has excellent high-temperature stability.

[0136] Depend on Figure 7 It can be seen that although the coefficient of thermal expansion of the thermal barrier coating prepared by the present invention is slightly smaller than that of 8YSZ, the coefficient of thermal expansion is 10.75 × 10⁻⁶ when x = 0.1, 0.3, and 0.5. -6 / ℃, 11.22×10 -6 / ℃, 11.34×10 -6 / ℃, which still has a significant advantage in thermal expansion coefficient compared to other new ceramic coatings currently available, making it suitable for thermal barrier coatings for aero engines.

[0137] Depend on Figure 8 It is known that the thermal barrier coating prepared by the present invention has the lowest thermal conductivity (as low as 1.63 W / mK at 1600℃), which is 15-20% lower than that of the 8YSZ coating, which is beneficial to improving its thermal insulation performance as a thermal barrier coating for hot-end components of aero-engines.

[0138] Table 1 shows that a higher Hf content results in a lower thermal conductivity of the coating, indicating better thermal barrier performance. However, excessive Hf content can lead to a decrease in the coefficient of thermal expansion, which in turn can cause a mismatch between the coating and the high-temperature alloy substrate of aero-engine hot components. During coating preparation, appropriately adjusting parameters such as spraying distance, spraying power, and powder properties can effectively control the microstructure within the coating, including the number of pores and voids, thereby improving its thermal barrier performance.

[0139] In summary, the thermal barrier coating material and the prepared thermal barrier coating provided by this invention have excellent mechanical properties and stable structure. They exhibit no weight loss or phase change from room temperature to 1600℃. Compared with the traditional 8YSZ coating, the coefficient of thermal expansion is not significantly different, and the thermal conductivity is lower (23-25% lower). The preparation method is simple and controllable, with high purity, low equipment requirements and low production costs, making it suitable for industrial applications.

[0140] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A thermal barrier coating material, characterized in that, The general formula for the thermal barrier coating material is (Zr 1-x Hf x ) 0.9 Y 0.1 O 1.95 , of which 0 <x≤0.5; The thermal barrier coating material is prepared by the following method, which includes the following steps: (1) The zirconium source, hafnium source and yttrium source are mixed to obtain a mixture; (2) After mixing the precipitant with the mixture obtained in step (1), the mixture is calcined to obtain a thermal barrier coating material; In the mixture described in step (1), the molar ratio of Zr, Hf, and Y, Zr:Hf:Y, is (4.5-8.1):(0.9-4.5):

1.

2. A method for preparing a thermal barrier coating material as described in claim 1, characterized in that, The preparation method includes the following steps: (1) The zirconium source, hafnium source and yttrium source are mixed to obtain a mixture; (2) After mixing the precipitant with the mixture obtained in step (1), the mixture is calcined to obtain a thermal barrier coating material; In the mixture described in step (1), the molar ratio of Zr, Hf, and Y, Zr:Hf:Y, is (4.5-8.1):(0.9-4.5):

1.

3. A method for preparing the thermal barrier coating material as described in claim 2, characterized in that, The zirconium source in step (1) includes soluble zirconium salts.

4. A method for preparing a thermal barrier coating material as described in claim 2, characterized in that, The zirconium source in step (1) includes ZrOCl2 and / or ZrCl4.

5. A method for preparing a thermal barrier coating material as described in claim 2, characterized in that, The hafnium source in step (1) includes soluble hafnium salts.

6. A method for preparing a thermal barrier coating material as described in claim 2, characterized in that, The hafnium source in step (1) includes HfCl4 and / or HfOCl2.

7. A method for preparing a thermal barrier coating material as described in claim 2, characterized in that, The yttrium source in step (1) includes yttrium oxides and / or soluble yttrium salts.

8. A method for preparing a thermal barrier coating material as described in claim 2, characterized in that, The yttrium source in step (1) includes Y2O3 and / or Y(NO3)3.

9. A method for preparing a thermal barrier coating material as described in claim 2, characterized in that, The precipitant in step (2) includes any one or a combination of at least two of ammonia, ammonium carbonate or ammonium bicarbonate.

10. A method for preparing a thermal barrier coating material as described in claim 2, characterized in that, The pH of the precipitant in step (2) is >13.

11. A method for preparing a thermal barrier coating material as described in claim 2, characterized in that, The calcination temperature in step (2) is 1000-1200℃.

12. A method for preparing a thermal barrier coating material as described in claim 2, characterized in that, The calcination time in step (2) is 2-4 hours.

13. A method for preparing a thermal barrier coating material as described in claim 2, characterized in that, After mixing in step (2), the mixture is washed, dried, ground and sieved in sequence.

14. A method for preparing a thermal barrier coating material as described in claim 13, characterized in that, The drying temperature is 60-80℃.

15. A method for preparing a thermal barrier coating material as described in claim 13, characterized in that, The drying time is 8-10 hours.

16. A method for preparing a thermal barrier coating material as described in claim 13, characterized in that, The particle size of the sieved powder is ≤200 mesh.

17. A thermal barrier coating, characterized in that, The thermal barrier coating is prepared from the thermal barrier coating material described in claim 1.

18. A method for preparing a thermal barrier coating as described in claim 17, characterized in that, The preparation method includes the following steps: (a) The thermal barrier coating material is mixed with a binder and a dispersant to obtain a spray powder; (b) Atmospheric plasma spraying is performed using the spray powder obtained in step (a) to obtain a thermal barrier coating.

19. The preparation method according to claim 18, characterized in that, The amount of adhesive used in step (a) is 5-8 wt% of the thermal barrier coating material.

20. The preparation method according to claim 18, characterized in that, The amount of dispersant used in step (a) is 4-6 wt% of the thermal barrier coating material.

21. The preparation method according to claim 18, characterized in that, After mixing in step (a), a second drying process is performed.

22. The preparation method according to claim 21, characterized in that, The second drying temperature is 60-70℃.

23. The preparation method according to claim 21, characterized in that, The second drying time is 15-20 minutes.

24. The preparation method according to claim 18, characterized in that, The particle size range of the sprayed powder in step (a) is 80-325 mesh.

25. The preparation method according to claim 18, characterized in that, The flowability of the sprayed powder in step (a) is 25-60s / 50g.

26. The preparation method according to claim 18, characterized in that, The loose bulk density of the sprayed powder in step (a) is 2.0-3.0 g / cm³. 3 .

27. The preparation method according to claim 18, characterized in that, The spray gun voltage for atmospheric plasma spraying in step (b) is 65-70V.

28. The preparation method according to claim 18, characterized in that, The spray gun current for atmospheric plasma spraying is 500-550A.

29. The preparation method according to claim 18, characterized in that, The argon flow rate for atmospheric plasma spraying is 30-40 L / min.

30. The preparation method according to claim 18, characterized in that, The hydrogen flow rate for atmospheric plasma spraying is 4-6 L / min.

31. The preparation method according to claim 18, characterized in that, The powder feeding rate for atmospheric plasma spraying is 25-40 g / min.

32. The preparation method according to claim 18, characterized in that, The spraying distance for atmospheric plasma spraying is 100-120mm.

33. An application of the thermal barrier coating as described in claim 17, characterized in that, The thermal barrier coating is used for the protection of hot-end components of aero-engines.

Images