CN113248255A - High-temperature heat-insulation fluorite type intermediate entropy oxide and preparation method thereof - Google Patents
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Abstract
The invention discloses a high-temperature heat-insulating fluorite type intermediate entropy oxide and a preparation method thereof, wherein the oxide is a single solid solution with cations randomly and uniformly distributed and has a chemical formula of (Ce)(0.2‑0.4)Zr(0.2‑0.4)Y(0.1‑0.3)La(0.1‑0.3))O2‑δThe crystal structure is a cubic defect fluorite phase, and the mixed entropy delta Sconf is 1.19kB～1.39kBWherein k isBThe molar gas constant is 8.31J/(K.mol); the preparation method of the oxide comprises the following steps: (1) taking a precursor raw material, and preparing a precursor solution; (2) adding ammonia water into the precursor solution, and stirring to obtain a mixed solution; (3) putting the mixed solution into an oven for drying; (4) carrying out heat treatment on the dried sample in an air atmosphere, cooling the sample to room temperature along with the furnace, and taking out the sample; (5) then placing the mixture at a high temperature for heat preservation to obtain a high-temperature heat-insulating fluorite type intermediate entropy oxide; the oxide can be used as thermal barrier coatingIn the layer material. The oxide has excellent phase stability at the temperature of more than 1500 ℃, good heat insulation, excellent oxidation resistance, simple preparation process and strong controllability.
Description
Technical Field
The invention relates to an oxide and a preparation method thereof, in particular to a high-temperature heat-insulation fluorite type intermediate entropy oxide and a preparation method thereof.
Background
Since the middle of the 20 th century, gas turbines have begun to be used in various fields such as aerospace, ships, energy, electric power, vehicles, and the like. High power and high efficiencyAnd low emissions are the main direction of development of modern gas turbines, and the increase of the turbine inlet air temperature can effectively improve the power and efficiency of the gas turbine. The use of high temperature heat insulating material such as thermal barrier coating can greatly reduce the surface temperature of high temperature alloy, and plays an important role in the aspect of thermal protection of turbine blades of gas turbines. By optimizing the structure and composition, the most widely used is currently a zirconia-based material (e.g., 8% Y)2O3-ZrO2) The prepared thermal barrier coating has good thermal insulation effect and excellent oxidation resistance. But it is at an elevated temperature (>1200 c) and premature spalling due to phase transformation and obvious grain coarsening, the increased volume change amount can expose the metal alloy material to dangerous high-temperature gas, and the high-temperature blade and other parts are damaged.
Disclosure of Invention
The purpose of the invention is as follows: the first object of the present invention is to provide a high-temperature heat-insulating fluorite type intermediate entropy oxide having good stability under high temperature, good heat-insulating property and excellent oxidation resistance, and the other object of the present invention is to provide a method for preparing the oxide.
The technical scheme is as follows: the high-temperature heat-insulating fluorite type intermediate entropy oxide is a single solid solution with cations randomly and uniformly distributed and has a chemical formula of (Ce)(0.2-0.4)Zr(0.2-0.4)Y(0.1-0.3)La(0.1-0.3))O2-δThe crystal structure is a cubic defect fluorite phase, and the mixed entropy delta Sconf is 1.19kB～1.39kB，kBThe molar gas constant is 8.31J/(K · mol).
The preparation method of the high-temperature heat-insulation fluorite type intermediate entropy oxide comprises the following steps:
(1) taking precursor raw materials: dissolving cerium nitrate hexahydrate, zirconium oxychloride octahydrate, yttrium nitrate hexahydrate and lanthanum chloride heptahydrate in water to prepare a precursor solution;
(2) adding ammonia water into the precursor solution, and stirring to obtain a mixed solution;
(3) putting the mixed solution into an oven for drying;
(4) carrying out heat treatment on the dried sample in an air atmosphere, cooling the sample to room temperature along with a furnace, and taking out the sample to obtain single-phase fluorite type intermediate entropy oxide;
(5) and (3) carrying out heat treatment on the single-phase fluorite type intermediate entropy oxide at high temperature to obtain the high-temperature heat-insulation fluorite type intermediate entropy oxide.
Wherein in the step (1), the molar ratio of cerium nitrate hexahydrate, zirconium oxychloride octahydrate, yttrium nitrate hexahydrate and lanthanum chloride heptahydrate is 2-4: 2-4: 1-3: 1-3, wherein the total molar concentration of the precursor solution is 0.08-0.5mol/L, and the temperature of the mixed solution is kept at 60-70 ℃ during dissolution; diluting ammonia water to a pH value of 10-11, slowly adding the diluted ammonia water into the precursor solution, adding the ammonia water, stirring until the pH value of the mixed solution is 9-10, keeping the temperature of the precursor solution at 60-70 ℃ during stirring, and stirring at a speed of 800-4000 rpm; in the step (3), when the mixed solution is dried, the oven is firstly heated to 80-90 ℃ for 20-24 hours to avoid splashing of the mixed solution due to boiling of water in the mixed solution, and then the temperature is increased to 120-130 ℃ for 10-12 hours. In the step (4), the heat treatment temperature is 1100-1500 ℃, the time is 1-4 h, in the step (5), the heat treatment temperature is 1500-1600 ℃, the heat preservation time is 16-60 h, the particle growth can be stabilized, the particle growth can reach a slow retardation state, the synthesized oxide has excellent phase stability above 1500 ℃, and the temperature rise speed of the heat treatment temperature is 2.5-8 ℃/min.
The working principle is as follows: different types of principal element metal ions in the prepared intermediate entropy oxide powder with the fluorite structure are uniformly and randomly distributed on the same position, so that phonon scattering is increased, and the reduction of thermal conductivity is facilitated; meanwhile, different sizes of metal ions can bring about serious lattice distortion, so that the resistance of atom migration is increased, and the crystal grains of the medium-high entropy material grow slowly under the same condition; according to the Gibbs free energy formula, the larger the entropy value is, the lower the free energy at high temperature is, so that the material prepared by the method has good phase stability at high temperature. Therefore, the prepared material shows excellent high-temperature stability and is expected to become an important candidate material of the thermal barrier coating.
Has the advantages that: compared with the prior art, the invention has the following remarkable advantages: 1. the oxide has excellent phase stability at the temperature of more than 1500 ℃, and after stabilization treatment, the crystal grain growth is slow, the heat insulation performance is good, and the oxidation resistance is excellent, so the oxide can be applied to a thermal barrier coating; 2. the preparation process is simple and has strong controllability.
Drawings
FIG. 1 is an XRD pattern of the sample prepared in example 1 and after heat treatment at 1500 ℃ for 16 h;
FIG. 2 is an XRD pattern of the sample prepared in example 2 and after heat treatment at 1500 ℃ for 20 h;
FIG. 3 is an XRD pattern of the sample prepared in example 3 and after heat treatment at 1500 ℃ for 20 h;
FIG. 4 is an elemental distribution plot for the sample prepared in example 4;
FIG. 5 is an XRD pattern of the sample prepared in example 4 and after heat treatment at 1500 ℃ for 20 h;
FIG. 6 is an XRD pattern of the sample prepared in example 5 and after heat treatment at 1500 deg.C for 56 h;
Detailed Description
Example 1
(1) According to the weight ratio of 2.5: 2.5: 2.5: 2.5, weighing the precursor raw materials according to the molar ratio: respectively weighing 4.342g, 3.223g, 3.830g and 3.714g of cerium nitrate hexahydrate, zirconium oxychloride octahydrate, yttrium nitrate hexahydrate and lanthanum chloride heptahydrate, putting the weighed medicines into 500ml of deionized water, placing a beaker in a constant-temperature water bath kettle, setting the temperature to be 60 ℃, and stirring to accelerate the dissolution of the medicines to obtain a precursor solution with the total molar concentration of 0.08 mol/L;
(2) diluting ammonia water to pH 11 with deionized water, slowly dropping the diluted ammonia water into the precursor solution to generate precipitate until the pH of the mixed solution is 10, wherein the precursor solution is placed in a constant-temperature water bath kettle at 60 ℃ and stirred in a matching manner at the stirring speed of 800 rpm;
(3) putting the generated precipitate and supernatant into an oven, drying at 80 deg.C for 24 hr, and then increasing the temperature to 130 deg.C, and drying for 12 hr;
(4) putting the dried sample into a muffle furnace, and heating at the temperature of 7 ℃/min toKeeping the temperature at 1100 ℃ for 1.5h, heating to 1500 ℃ at a speed of 5 ℃/min, keeping the temperature for 4h, cooling the sample to room temperature along with the furnace, and taking out to obtain the prepared powder (Ce)0.25Zr0.25Y0.25La0.25)O2-δ. Calculating formula according to entropy:
wherein k isB8.31J/(K.mol) is a molar gas constant, N is the number of components in the system, and xiRepresents the atomic percentage of the ith component in the system;
the entropy value of the material is 1.38kB；
(5) And (3) treating the oxide powder at 1500 ℃ for 16h to obtain the high-temperature heat-insulating fluorite type medium-entropy oxide with slowly-growing particles.
The prepared intermediate entropy oxide and an XRD (X-ray diffraction) pattern after heat treatment at 1500 ℃ for 16h are shown in figure 1, and the prepared powder is of a single-phase fluorite structure, and the single-phase structure is still maintained after heat treatment at high temperature, so that the good high-temperature phase stability of the powder is proved. The grain size of the prepared fluorite type intermediate entropy oxide after heat treatment at 1500 ℃ for 16h is calculated by Williamson-Hall formula and is 262.0 nm; the average particle size, as counted via SEM pictures, was 3.0 μm.
Example 2
(1) According to the following steps of 3: 3: 2: 2, weighing the precursor raw materials in a molar ratio: respectively weighing 5.190g, 3.867g, 3.062g and 2.971g of cerium nitrate hexahydrate, zirconium oxychloride octahydrate, yttrium nitrate hexahydrate and lanthanum chloride heptahydrate, putting the weighed medicines into 500ml of deionized water, placing a beaker in a constant-temperature water bath kettle, setting the temperature to be 60 ℃, and stirring to accelerate the dissolution of the medicines to obtain a precursor solution with the total molar concentration of 0.08 mol/L;
(2) diluting ammonia water to pH 11 with deionized water, slowly dropping the diluted ammonia water into the precursor solution to generate precipitate until the pH of the mixed solution is 10, wherein the precursor solution is placed in a constant-temperature water bath kettle at 60 ℃ and is stirred in a matching manner at the stirring speed of 1200 rpm;
(3) putting the generated precipitate and supernatant into an oven, drying at 80 deg.C for 24 hr, and then increasing the temperature to 130 deg.C, and drying for 12 hr;
(4) putting the dried sample into a muffle furnace, heating to 1100 ℃ at a speed of 7 ℃/min, preserving heat for 1.5h, cooling the sample to room temperature along with the furnace, and taking out to obtain the prepared powder (Ce)0.3Zr0.3Y0.2La0.2)O2-δ. The entropy value of the material is 1.37k according to an entropy value calculation formulaB；
(5) And (3) treating the oxide powder at 1500 ℃ for 20h to obtain the high-temperature heat-insulating fluorite type medium-entropy oxide with slowly-growing particles.
The prepared intermediate entropy oxide and an XRD (X-ray diffraction) pattern after heat treatment at 1500 ℃ for 20h are shown in figure 2, and the figure shows that the prepared powder is of a single-phase fluorite structure, and the single-phase structure is still maintained after the heat treatment at high temperature, so that the good high-temperature phase stability of the powder is proved.
Example 3
(1) According to the following steps of 4: 4: 1: 1, weighing precursor raw materials according to a molar ratio: respectively weighing 6.949g, 5.158g, 1.530g and 1.485g of weighed medicines, putting the weighed medicines into 500ml of deionized water, placing a beaker in a constant-temperature water bath kettle, setting the temperature to be 60 ℃, and stirring to accelerate the dissolution of the medicines to obtain a precursor solution with the total molar concentration of 0.08 mol/L;
(2) diluting ammonia water to pH 11 with deionized water, slowly dropping the diluted ammonia water into the precursor solution to generate precipitate until the pH of the mixed solution is 10, wherein the precursor solution is placed in a constant-temperature water bath kettle at 60 ℃ and stirred in a matching manner at the stirring speed of 2000 rpm;
(3) putting the generated precipitate and supernatant into an oven, drying at 80 deg.C for 24 hr, and then increasing the temperature to 130 deg.C, and drying for 12 hr;
(4) putting the dried sample into a muffle furnace, heating to 1100 ℃ at the speed of 7 ℃/min, preserving the heat for 1.5h,cooling the sample to room temperature with the furnace, and taking out to obtain the prepared powder (Ce)0.4Zr0.4Y0.1La0.1)O2-δ. The entropy value of the material is 1.19k according to an entropy value calculation formulaB；
(5) And (3) treating the oxide powder at 1500 ℃ for 20h to obtain the high-temperature heat-insulating fluorite type medium-entropy oxide with slowly-growing particles.
The prepared intermediate entropy oxide and an XRD (X-ray diffraction) pattern after heat treatment at 1500 ℃ for 20h are shown in figure 3, and the figure shows that the prepared powder is of a single-phase fluorite structure, and the single-phase structure is still maintained after the heat treatment at high temperature, so that the good high-temperature phase stability of the powder is proved.
Example 4
(1) According to the following steps: 2: 3: 3, weighing precursor raw materials according to a molar ratio: respectively weighing 6.954g, 5.150g, 9.195g and 8.912g of cerium nitrate hexahydrate, zirconium oxychloride octahydrate, yttrium nitrate hexahydrate and lanthanum chloride heptahydrate, putting the weighed medicines into 250ml of deionized water, placing a beaker in a constant-temperature water bath kettle, setting the temperature to be 60 ℃, and stirring to accelerate the dissolution of the medicines to obtain a precursor solution with the total molar concentration of 0.32 mol/L;
(2) diluting ammonia water to pH 11 with deionized water, slowly dropping the diluted ammonia water into the precursor solution to generate precipitate until the pH of the mixed solution is 10, wherein the precursor solution is placed in a constant-temperature water bath kettle at 60 ℃ and stirred in a matching manner at the stirring speed of 4000 rpm;
(3) putting the generated precipitate and supernatant into an oven, drying at 80 deg.C for 24 hr, and then increasing the temperature to 130 deg.C, and drying for 12 hr;
(4) putting the dried sample into a muffle furnace, heating to 1100 ℃ at the speed of 7 ℃/min, preserving heat for 1.5h, heating to 1500 ℃ at the speed of 5 ℃/min, preserving heat for 4h, cooling the sample to room temperature along with the furnace, and taking out to obtain the prepared powder (Ce)0.2Zr0.2Y0.3La0.3)O2-δ. The entropy value of the material is 1.37k according to an entropy value calculation formulaB；
(5) And (3) treating the oxide powder at 1500 ℃ for 20h to obtain the high-temperature heat-insulating fluorite type medium-entropy oxide with slowly-growing particles.
The element distribution diagram of the prepared sample is obtained by a field emission scanning electron microscope, as shown in fig. 4, the distribution of each element of the prepared sample is very uniform; the prepared intermediate entropy oxide and an XRD (X-ray diffraction) pattern after heat treatment at 1500 ℃ for 20h are shown in figure 5, and the figure shows that the prepared powder is of a single-phase fluorite structure, and the single-phase structure is still maintained after the heat treatment at high temperature, so that the good high-temperature phase stability of the powder is proved.
Example 5
(1) According to the weight ratio of 2.5: 2.5: 2.5: 2.5, weighing the precursor raw materials according to the molar ratio: respectively weighing 4.342g, 3.223g, 3.830g and 3.714g of cerium nitrate hexahydrate, zirconium oxychloride octahydrate, yttrium nitrate hexahydrate and lanthanum chloride heptahydrate, putting the weighed medicines into 500ml of deionized water, placing a beaker in a constant-temperature water bath kettle, setting the temperature to be 60 ℃, and stirring to accelerate the dissolution of the medicines to obtain a precursor solution with the total molar concentration of 0.08 mol/L;
(2) diluting ammonia water to pH 11 with deionized water, slowly dropping the diluted ammonia water into the precursor solution to generate precipitate until the pH of the mixed solution is 10, wherein the precursor solution is placed in a constant-temperature water bath kettle at 60 ℃ and stirred in a matching manner at the stirring speed of 800 rpm;
(3) putting the generated precipitate and supernatant into an oven, drying at 80 deg.C for 24 hr, and then increasing the temperature to 130 deg.C, and drying for 12 hr;
(4 putting the dried sample into a muffle furnace, heating to 1100 ℃ at the speed of 7 ℃/min, preserving heat for 1.5h, heating to 1500 ℃ at the speed of 5 ℃/min, preserving heat for 4h, cooling the sample to room temperature along with the furnace, and taking out to obtain the prepared powder (Ce)0.25Zr0.25Y0.25La0.25)O2-δ. The entropy value of the material is 1.38k according to an entropy value calculation formulaB；
(5) Treating the oxide powder at 1500 ℃ for 16h to obtain a high-temperature heat-insulating fluorite type medium-entropy oxide with slowly-growing particles;
(6) and then the sample is continuously processed at 1500 ℃ for 40h, and is taken out after being cooled along with the furnace, namely the sample is processed at 1500 ℃ for 56 h.
The prepared fluorite type intermediate entropy oxide and XRD (X-ray diffraction) pattern after heat treatment at 1500 ℃ for 56 hours are shown in figure 6, and it can be known that the oxide can still keep the same phase structure after being treated at high temperature for a long time, and the oxide is proved to have good high-temperature phase stability; the grain size of the prepared fluorite medium-entropy oxide after heat treatment at 1500 ℃ for 56 hours is calculated by a Williamson-Hall formula and is 264.5 nm; the particle size was 3.4 μm as counted via SEM pictures. Compared with the grain size and the grain size after heat treatment at 1500 ℃ for about 16h in example 1, the change is not large, and the stability of the prepared medium-entropy fluorite oxide at high temperature is good, and the grain growth reaches a very slow state after heat treatment at 1500 ℃ for about 16 h.
Claims (8)
1. The high-temperature heat-insulating fluorite type intermediate entropy oxide is characterized in that the oxide is a single solid solution with cations randomly and uniformly distributed and has the chemical formula of (Ce)(0.2-0.4)Zr(0.2-0.4)Y(0.1-0.3)La(0.1-0.3))O2-δThe crystal structure is a cubic defect fluorite phase, and the mixed entropy delta Sconf is 1.19kB～1.39kBWherein k isBThe molar gas constant is 8.31J/(K · mol).
2. A method for preparing a high-temperature insulating fluorite type intermediate entropy oxide according to claim 1, characterized in that it comprises the following steps:
(1) taking precursor raw materials: dissolving cerium nitrate hexahydrate, zirconium oxychloride octahydrate, yttrium nitrate hexahydrate and lanthanum chloride heptahydrate in water to prepare a precursor solution;
(2) adding ammonia water into the precursor solution, and stirring to obtain a mixed solution;
(3) putting the mixed solution into an oven for drying;
(4) carrying out heat treatment on the dried sample in an air atmosphere, cooling the sample to room temperature along with a furnace, and taking out the sample to obtain single-phase fluorite type intermediate entropy oxide;
(5) and (3) carrying out heat treatment on the single-phase fluorite type intermediate entropy oxide at high temperature to obtain the high-temperature heat-insulation fluorite type intermediate entropy oxide.
3. The method for preparing a high-temperature insulating fluorite type intermediate entropy oxide according to claim 2, wherein the molar ratio of cerium nitrate hexahydrate, zirconium oxychloride octahydrate, yttrium nitrate hexahydrate and lanthanum chloride heptahydrate in step (1) is 2-4: 2-4: 1-3: 1-3, wherein the total molar concentration of the precursor solution is 0.08-0.5mol/L, and the temperature of the mixed solution is kept at 60-70 ℃ during dissolution.
4. The preparation method of the high-temperature heat-insulating fluorite type intermediate entropy oxide according to claim 2, characterized in that in the step (2), ammonia water is firstly diluted to pH 10-11 and then slowly added into the precursor solution, the ammonia water is added and stirred until the pH of the mixed solution is 9-10, the temperature of the precursor solution is kept between 60 ℃ and 70 ℃ while stirring, and the stirring speed is 800rpm to 4000 rpm.
5. The preparation method of the high-temperature heat-insulating fluorite type intermediate entropy oxide as claimed in claim 2, wherein in the step (3), when the mixed solution is dried, the temperature of the oven is firstly increased to 80-90 ℃ for 20-24 h, and then is increased to 120-130 ℃ for 10-12 h.
6. The method for preparing a high-temperature heat-insulating fluorite type intermediate entropy oxide according to claim 2, wherein in the step (4), the heat treatment temperature is 1100-1500 ℃ and the time is 1-4 h.
7. The method for preparing a high-temperature heat-insulating fluorite type intermediate entropy oxide according to claim 2, wherein in the step (5), the heat treatment temperature is 1500-1600 ℃, and the heat preservation time is 16-60 h.
8. The method for preparing a high-temperature heat-insulating fluorite type intermediate entropy oxide according to claim 6 or 7, wherein the temperature rise rate of the heat treatment temperature is 2.5-8 ℃/min.
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114920559A (en) * | 2022-06-07 | 2022-08-19 | 西北工业大学 | High-entropy oxide powder material for thermal barrier coating and preparation method and application thereof |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108946787A (en) * | 2018-07-23 | 2018-12-07 | 安徽工业大学 | A kind of preparation method of the high entropy oxide powder material of Property of Rare earth based Fluorite Type |
| CN109569565A (en) * | 2018-11-29 | 2019-04-05 | 南昌大学 | One kind being used for methane oxidation coupling non-stoichiometric defect fluorite method for preparing catalyst and application |
| CN109987935A (en) * | 2019-03-20 | 2019-07-09 | 太原理工大学 | (ZrHfCeTiZn) O with fluorite type structure2The high entropy oxide ceramic powder body of-δ and block preparation method |
| CN111763087A (en) * | 2020-06-29 | 2020-10-13 | 西安交通大学 | Series of cubic fluorite type high-entropy cerium oxide nano-powder and preparation method thereof |
-
2021
- 2021-03-08 CN CN202110249663.7A patent/CN113248255B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108946787A (en) * | 2018-07-23 | 2018-12-07 | 安徽工业大学 | A kind of preparation method of the high entropy oxide powder material of Property of Rare earth based Fluorite Type |
| CN109569565A (en) * | 2018-11-29 | 2019-04-05 | 南昌大学 | One kind being used for methane oxidation coupling non-stoichiometric defect fluorite method for preparing catalyst and application |
| CN109987935A (en) * | 2019-03-20 | 2019-07-09 | 太原理工大学 | (ZrHfCeTiZn) O with fluorite type structure2The high entropy oxide ceramic powder body of-δ and block preparation method |
| CN111763087A (en) * | 2020-06-29 | 2020-10-13 | 西安交通大学 | Series of cubic fluorite type high-entropy cerium oxide nano-powder and preparation method thereof |
Non-Patent Citations (1)
| Title |
|---|
| 张丰年等: "高熵陶瓷(Zr1/7Hf1/7Ce1/7Y2/7La2/7)O2-δ的制备及烧结行为", 《无机材料学报》 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114920559A (en) * | 2022-06-07 | 2022-08-19 | 西北工业大学 | High-entropy oxide powder material for thermal barrier coating and preparation method and application thereof |
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