A perovskite-type ceramic material with high infrared emissivity, its preparation method and application

Abstract

The present invention discloses a perovskite-type ceramic material with high infrared emissivity, its preparation method and application. The molecular formula of the ceramic material is Sr(Zr 1‑y X y )O z , where X is Mg, Ca, Mn, Fe, Co, Ni, Cu or Zn; the preparation method: adding a water-soluble strontium salt, a water-soluble X salt and a water-soluble zirconium salt into deionized water and heating and dissolving in a water bath to obtain a mixed system A; under the water bath condition, adding citric acid to the mixed system A and continuing to stir to obtain a mixed system B; under the water bath condition, dropwise adding ammonia water to the mixed system B and continuing to stir to obtain a mixed system C; drying and drying the mixed system C, and grinding the dried product obtained after drying to obtain a precursor powder; sintering the precursor powder under normal pressure. The present invention can solve the technical problem that the existing SrZrO3 ceramic material has a low infrared emissivity in the 1-22 μm band between room temperature and 600 °C.

Description

Technical Field

[0001] The present invention relates to the technical field of perovskite ceramic materials. Specifically, it is a perovskite-type ceramic material with high infrared emissivity, its preparation method and application. Background Art

[0002] During the operation of a high-temperature sintering furnace, some heat will be lost outward through the furnace chamber and furnace wall, resulting in a decrease in furnace temperature and an increase in energy consumption; during the service process of high-power devices, the whole or part will be in a high-temperature state, causing a decrease in device performance and a shortened lifespan; when an aerospace plane re-enters the atmosphere, the front fuselage skin will be in a high-temperature state due to aerodynamic friction. If heat accumulates and cannot be quickly dissipated, it will cause damage to the fuselage and affect the normal operation of the aircraft. Therefore, it is necessary to design and develop materials for solving the heat loss problem of high-temperature sintering furnaces, the high-temperature problem of high-power devices, and the high-temperature damage problem of aerospace planes.

[0003] High-infrared radiation ceramic materials (infrared emissivity ε>0.8 in a certain infrared band) can maximize the conversion of the thermal energy of the material into infrared radiation energy. When using high-infrared radiation ceramic materials as the inner furnace material of a high-temperature sintering furnace, it can radiate as much thermal energy on the inner furnace back into the furnace, thus maintaining the furnace temperature and improving the energy utilization efficiency; when preparing high-infrared radiation ceramic materials on the outer surface of the alloy shell of high-power devices and the skin of aerospace planes, it can quickly radiate the thermal energy on the alloy shell and skin to the atmosphere, realizing heat dissipation of high-power devices and thermal protection of aerospace planes. In summary, high-infrared radiation ceramic materials have important applications in the fields of energy conservation, heat dissipation, and thermal protection, and are effective functional materials to ensure the normal service and long lifespan of high-power devices and aerospace planes.

[0004] According to Wien's law, the wavelength of the maximum infrared radiation intensity of an absolute black body is proportional to the temperature, that is, the wavelength corresponding to the highest infrared radiation energy of an object gradually shifts to shorter wavelengths as the temperature of the object increases. Therefore, for high-infrared radiation materials applied to high-temperature environments, it is often required that they have a high emissivity in a shorter infrared band, such as 3-5 μm. At the same time, since the infrared radiation energy in the 1-22 μm band accounts for more than 95% of the total energy, it is also necessary to have high infrared radiation performance in this band. However, the emissivity of current high-infrared radiation ceramic materials in the 3-5 μm and 1-22 μm bands often concentrates in the range of 0.8-0.93. Therefore, the infrared radiation performance of high-infrared radiation ceramic materials needs to be further improved. SrZrO3 has potential application value in the fields of aerospace, energy, and engines due to its low preparation cost, high-temperature stability, good chemical stability, good strength and hardness, as well as wear resistance and heat fatigue resistance.

[0005] However, according to the literature (E.B. Li, W Ma, P Zhang, et al., The effect of Al 3+ doping on the infrared radiation and thermophysical properties of SrZrO3 perovskites as potential low thermal infrared material, Acta Mater., 209(2021), 11679), the infrared emissivity of SrZrO3 in the 3-5μm band between room temperature and 600°C is between 0.5 and 0.7, and the infrared emissivity in the 1-22μm band is about 0.7, which makes it difficult for SrZrO3 to be used as a high-infrared radiation ceramic in corresponding fields. Summary of the Invention

[0006] Therefore, the technical problem to be solved by the present invention is to provide a perovskite-type ceramic material with high infrared emissivity and its preparation method, so as to solve the technical problem that the existing SrZrO3 ceramic material has a low infrared emissivity in the 3-5μm band and 1-22μm band between room temperature and 600°C.

[0007] To solve the above technical problems, the present invention provides the following technical solutions:

[0008] A perovskite-type ceramic material with high infrared emissivity, with the molecular formula Sr(Zr 1-y X y )O z, X is Mg, Ca, Mn, Fe, Co, Ni, Cu or Zn. This high-infrared emissivity perovskite ceramic material of the present invention has a high infrared emissivity in the range of 3-5 μm and 1-22 μm, can maximize the advantages of SrZrO3, and is suitable for the fields of energy conservation, heat dissipation and thermal protection. The present invention uses Mg, Ca, Mn, Fe, Co, Ni, Cu or Zn to replace a part of Zr in the SrZrO3 ceramic material because the valence states of these metal elements are +2 or +3 when in ionic state. By replacing Zr with a valence state of +4 with X, oxygen vacancies can be successfully introduced into the unit cell. The introduction of oxygen vacancies can increase the lattice distortion, thereby enhancing the lattice vibration, and finally enhancing the infrared absorption ability of the unit cell, making the SrZrO3 ceramic material have a high infrared emissivity at high temperatures; and compared with Zr, these metal elements also have the characteristics of low raw material prices and easy availability, which can greatly reduce the production cost of the high-infrared emissivity perovskite ceramic material; in addition, most of the oxides of these elements such as Mg, Ca, Mn, Fe, Co, Ni, Cu or Zn are bio- and environment-friendly materials, which can greatly reduce the biological harm and environmental pollution generated during the production of the high-infrared emissivity perovskite ceramic material.

[0009] For the above high-infrared emissivity perovskite ceramic material, the value range of y is 0.05-0.5, and the value range of z is 0.5-2.9375. When the value of y is less than 0.05, the improvement of the infrared emissivity of the material by the substitution element is not obvious. When the value of y is greater than 0.5, due to the increase in formation energy and the imbalance of valence state transition, it is ultimately difficult to form a single perovskite phase.

[0010] A preparation method of a high-infrared emissivity perovskite ceramic material includes the following steps:

[0011] Step (1), Add water-soluble strontium salt, water-soluble X salt and water-soluble zirconium salt to deionized water, heat in a water bath and stir well to dissolve to obtain a mixed system A;

[0012] Step (2), Under the water bath condition, add citric acid to the mixed system A and continue to stir to obtain a mixed system B;

[0013] Step (3), Under the water bath condition, add ammonia water dropwise to the mixed system B and continue to stir to obtain a mixed system C;

[0014] Step (4), Dry and bake the mixed system C, and grind the dried product obtained after drying to obtain a precursor powder;

[0015] Step (5), Sinter the precursor powder under normal pressure. After the sintering is completed, the high-infrared emissivity perovskite ceramic material is prepared; the molecular formula of the high-infrared emissivity perovskite ceramic material is Sr(Zr 1-yX y )O z , where X is Mg, Ca, Mn, Fe, Co, Ni, Cu or Zn.

[0016] For the preparation method of the above perovskite-type ceramic material with high infrared emissivity, in step (1), the water-soluble strontium salt is one or two or more of strontium acetate Sr(CH3COO)2, strontium nitrate Sr(NO3)2 and strontium bromide SrBr2; the water-soluble X salt is one or two or more of magnesium acetate Mg(CH3COO)2, magnesium chloride MgCl2, calcium acetate monohydrate Ca(CH3COO)2·H2O, calcium chloride hexahydrate CaCl2·6H2O, manganese acetate Mn(CH3COO)2, manganese chloride MnCl2, manganese nitrate Mn(NO3)2, iron(III) nitrate nonahydrate Fe(NO3)3·9H2O, ferric chloride FeCl3, cobalt(II) chloride hexahydrate CoCl2·6H2O, cobalt(II) acetate tetrahydrate Co(CH3COO)2·4H2O, nickel(II) acetate tetrahydrate Ni(CH3COO)2·4H2O, nickel(II) chloride hexahydrate NiCl2·6H2O, copper(II) nitrate trihydrate Cu(NO3)2·3H2O, copper acetate Cu(CH3COO)2, copper chloride CuCl2, zinc acetate Zn(CH3COO)2 and zinc chloride ZnCl2; the water-soluble zirconium salt is one or two or more of zirconyl chloride ZrOCl2, zirconyl nitrate ZrO(NO3)2 or zirconium acetate Zr(CH3COO)4;

[0017] In step (1), in the mixed system A: the molar ratio of strontium ions, X ions and zirconium ions is (1 - 1.3):(0.05 - 0.5):(0.5 - 0.95). When the molar ratio of the three is within this range, the perovskite-type ceramic material prepared will not generate a second-phase product, and a single perovskite-phase ceramic material can be obtained, and the infrared emissivity of the perovskite-type ceramic material can be significantly improved; the total mass ratio of the water-soluble strontium salt, the water-soluble X salt and the water-soluble zirconium salt to the mass of deionized water is 1:(3 - 8). If the amount of deionized water used is too small, the phenomenon that the water-soluble salt cannot be completely dissolved will occur, and if the amount of deionized water used is too large, the subsequent drying time will be too long, ultimately resulting in an extended process cycle and increased energy consumption; the water bath heating temperature is 40 - 60 °C, and the water bath heating and stirring time is 1 - 1.5 h to fully dissolve each raw material in deionized water and make each element fully and evenly mixed.

[0018] In the preparation method of the above high-infrared emissivity perovskite-type ceramic material, in step (2), the molar ratio of the amount of citric acid added to the total amount of cations in the mixed system A is 1:(1.2 - 2), so as to ensure that there are enough citrate ions to react with the cations in the mixed system A to form a sol; if the amount of citric acid used is too small, it is difficult to fully react with the cations, while if the amount of citric acid used is too large, there will be an excess of citrate ions in the system A, resulting in waste of citric acid and an increase in the amount of ammonia water added and waste in the subsequent step (3); the water bath heating temperature is 50 - 70 °C, and the water bath heating and stirring time is 1 - 1.5 h, so as to accelerate the reaction rate of the complexation reaction and ensure that the complexation reaction occurs fully.

[0019] In the preparation method of the above high-infrared emissivity perovskite-type ceramic material, in step (3), the amount of ammonia water added is based on the standard that the pH of the mixed system C is between 8 and 10, and the ammonia water is added dropwise within 15 - 30 min (a gel with relatively ideal quality can be formed under this alkaline condition), and the mass concentration of the ammonia water is 25 - 28 wt%; the water bath heating temperature is 80 - 95 °C, and it is more conducive to the full formation of the gel at this water bath temperature, and the water bath heating and stirring time is 1.5 - 2 h, so that the reaction occurs fully.

[0020] In the preparation method of the above high-infrared emissivity perovskite-type ceramic material, in step (4), the drying temperature is 120 °C, and the drying time is 12 - 24 h. The product obtained under this drying condition has appropriate particle size and hardness; the grinding time of the dried product is 1 - 1.5 h, so as to ensure that the dry gel is fully broken; the particle size of the precursor powder is 50 - 100 μm.

[0021] For the preparation method of the above-mentioned perovskite-type ceramic material with high infrared emissivity, in step (5), the sintering conditions for the precursor powder sintering under atmospheric pressure are as follows: heating up to 300 °C at a heating rate of 3 - 5 °C / min, holding for 2 - 5 h. Under this temperature condition, metal citrate (zirconium, strontium, X) and ammonium citrate undergo decomposition reactions to generate metal (zirconium, strontium, X) oxides, carbon dioxide, water, and ammonia; if the holding temperature in this stage is lower than 300 °C or the holding time is too short during this stage, it will lead to insufficient decomposition of metal citrate (zirconium, strontium, X) in the precursor powder. If the holding temperature is higher than 300 °C or the holding time is too long, it will easily cause the decomposition reaction of the precursor powder to release a large amount of gas violently and rapidly, and the large amount of gas will cause the powder to expand excessively, thus leading to the powder overflowing from the crucible, which not only affects the product yield but also affects the formation of a single-phase perovskite material in subsequent sintering; then heating up to 600 °C at a heating rate of 3 - 5 °C / min and holding for 2 - 5 h. If the holding temperature in the second stage is lower than 600 °C or the holding time is too short, it will affect the further sufficient decomposition of the remaining undecomposed precursor powder. If the holding temperature is higher than 600 °C, it will cause the decomposition reaction of the precursor powder to occur violently and expand excessively, which will also lead to the precursor powder overflowing from the crucible; by controlling the heating and holding conditions in the above two stages, the precursor powder can be fully sintered to generate a product of metal (zirconium, strontium, X) oxides, creating conditions for the formation of subsequent perovskite materials; then heating up to 1000 °C - 1600 °C at a heating rate of 3 - 10 °C / min and holding for 3 - 6 h. If the holding temperature in the third stage is lower than 1000 °C or higher than 1600 °C, it will lead to the inability to generate single perovskite phase ceramic powder, or cause overfiring of the ceramic powder and the formation of a second phase; if the holding time in the third stage is too short, it will also lead to the inability to generate single perovskite phase ceramic powder due to insufficient sintering, and if the holding time is too long, it will lead to overfiring and grain growth phenomena; finally, naturally cooling to room temperature. The sintering of the present invention is carried out in a way of gradient heating and then holding in order to perform step-by-step pre-sintering on the precursor powder at 300 °C and 600 °C, so that the precursor powder decomposes sufficiently and slowly to obtain the target intermediate product, and the target intermediate product generates perovskite phase ceramic powder under the sintering conditions of the present invention; if directly heating up to 1000 - 1600 °C at a heating rate of 3 - 5 °C / min and then holding, it will not only affect the introduction of oxygen vacancies in the unit cell of the final ceramic material, affect the increase in its lattice distortion, and further affect the infrared emissivity of the finally prepared ceramic material, but also cause expansion due to the rapid decomposition of the precursor powder at high temperature to generate a large amount of gas, causing the dry gel and powder to be extruded from the crucible by the expanding gas, resulting in powder loss and even causing pollution or damage to the sintering furnace.

[0022] In the preparation method of the above high-infrared emissivity perovskite-type ceramic material, in step (1), the water-soluble strontium salt is strontium nitrate; the water-soluble X salt is copper nitrate trihydrate; the water-soluble zirconium salt is zirconium acetate; in the mixed system A: the molar ratio of strontium ions, X ions and zirconium ions is 1:0.375:0.625; the total mass ratio of the water-soluble strontium salt, the water-soluble X salt and the water-soluble zirconium salt to the mass of deionized water is 1:4; the water bath heating temperature is 50 °C, and the water bath heating and stirring time is 1 h;

[0023] In step (2), the molar ratio of the amount of citric acid added to the total amount of cations in the mixed system A is 1:1.2; the water bath heating temperature is 50 °C, and the water bath heating and stirring time is 1 h;

[0024] In step (3), the addition of ammonia water is stopped when the pH of the mixed system C is 10. The ammonia water is added dropwise within 30 min, and the mass concentration of the ammonia water is 26 wt%; the water bath heating temperature is 80 °C, and the water bath heating and stirring time is 1.5 h;

[0025] In step (4), the drying temperature is 120 °C, the drying time is 12 h, the grinding time of the dried product is 1 h, and the particle size of the precursor powder is 60 - 100 μm;

[0026] In step (5), the sintering conditions for sintering the precursor powder under atmospheric pressure are: heating at a heating rate of 3 °C / min to 300 °C and holding for 2 h; then heating at a heating rate of 3 °C / min to 600 °C and holding for 2 h; then heating to 1000 °C at a heating rate of 3 °C / min and holding for 6 h; finally, cooling naturally to room temperature.

[0027] An application of a high-infrared emissivity perovskite-type ceramic material, using the above high-infrared emissivity perovskite-type ceramic material as the inner lining material of a high-temperature sintering furnace, or as the radiation heat dissipation material for high-power optical and electronic devices.

[0028] The technical solution of the present invention has achieved the following beneficial technical effects:

[0029] 1. The present invention prepares the precursor powder by the sol-gel method and burns the precursor powder by the atmospheric pressure sintering method to make the raw materials generate high-infrared emissivity ceramic powder with a simple structural formula Sr(Zr 1-y X y )O z The preparation method of the present invention has the advantages of low cost, simple process, low sintering temperature, energy conservation and environmental protection, etc. The prepared ceramic has excellent high-infrared radiation performance.

[0030] 2. The Sr(Zr 1-y X y )O zIt has excellent high-infrared radiation performance. Its infrared emissivity in the range of 3-5μm from room temperature to 600°C can reach up to 0.973 at most, and the infrared emissivity in the range of 1-22μm can reach up to 0.965 at most. It is applicable to energy conservation of high-temperature sintering furnaces, heat dissipation of high-power devices, and thermal protection of aerospace planes.

[0031] 3. The preparation method of the high-infrared emissivity perovskite-type ceramic material of the present invention selects specific types of water-soluble metal salts, controls their ratios with water-soluble strontium salts and water-soluble zirconium salts, and uses the sol-gel method to prepare Sr(Zr 1-y X y )O z precursor powder, controls the precursor powder within the range of 50-100μm, and uses a three-stage gradient heating and heat preservation method to perform atmospheric pressure sintering treatment on the precursor powder, so that the precursor powder can obtain decomposition products after step-by-step pre-sintering, and the decomposition products can form a single perovskite-phase ceramic powder under the sintering conditions in the last stage, enabling the introduced specific types of metals to fully play their role in enhancing the infrared absorption ability of the unit cell. Description of the Drawings

[0032] Figure 1 The microscopic morphology diagram of the Sr(Zr 0.625 Cu 0.375 )O 2.625 ceramic prepared in Example 1 of the present invention;

[0033] Figure 2 The XRD patterns of the Sr(Zr 1-y X y )O z ceramics prepared in Examples 1-3 of the present invention and related standard diffraction patterns;

[0034] Figure 3 The infrared emissivity of the Sr(Zr 1-y X y )O z ceramics prepared in Examples 1-3 of the present invention within the range of 1-22μm from room temperature to 600°C. Detailed Embodiments

[0035] Example 1

[0036] The preparation method of the high-infrared emissivity perovskite-type ceramic material in this example includes the following steps:

[0037] Step (1), Sr(NO3)2, Cu(NO3)2·3H2O, and Zr(C2H3O2)4 are added into deionized water which is 4 times the total mass of Sr(NO3)2, Cu(NO3)2·3H2O, and Zr(C2H3O2)4 in a molar ratio of 1:0.375:0.625, heated in a water bath at 50°C, and stirred for 1h to obtain a uniformly mixed mixed system A;

[0038] Step (2), adding citric acid to the mixed system A under 50° C. water bath conditions and continuing stirring for 1 hour to obtain a mixed system B, wherein the ratio of the amount of citric acid added to the total amount of cations in the mixed system A is 1:1.2;

[0039] Step (3), adding aqueous ammonia dropwise to the mixed system B in a water bath at 80° C. and continuing stirring for 1.5 h to obtain a mixed system C; when the pH of the mixed system C is 10, the addition of aqueous ammonia is stopped, and the addition of aqueous ammonia is completed within 30 min, and the mass concentration of aqueous ammonia is 26 wt %;

[0040] Step (4), drying the mixed system C at 120° C. for 12 hours, and grinding the dried product obtained after drying using an agate mortar for 1 hour to obtain a precursor powder; the particle size of the precursor powder is 60 to 100 μm;

[0041] Step (5), pouring the precursor powder into a zirconia crucible so that the powder is evenly distributed in the crucible, placing the crucible in a muffle furnace for normal pressure sintering; the sintering conditions of the precursor powder at normal pressure are: heating to 300°C at a heating rate of 3°C / min, keeping warm for 2h; then heating to 600°C at a heating rate of 3°C / min, keeping warm for 2h; then heating to 1000°C at a heating rate of 3°C / min, keeping warm for 6h; finally naturally cooling to room temperature, thus preparing a high infrared emissivity perovskite ceramic material.

[0042] The molecular formula of the high infrared emissivity perovskite ceramic material finally prepared in this embodiment is Sr(Zr 0.625 Cu 0.375 ) 2.625 . Figure 1 The Sr(Zr) prepared in this example 0.625 Cu 0.375 ) 2.625 The microscopic morphology of the ceramic powder shows that the powder is micron-sized particles. This is because the preparation method of this embodiment can refine the grains.

[0043] After testing, the Sr(Zr 0.625 Cu 0.375 ) 2.625The infrared emissivity of the ceramic powder at room temperature to 600 °C is 0.883 to 0.962 in the 3 - 5 μm band, where it is 0.962 at 600 °C; and 0.893 to 0.965 in the 1 - 22 μm band, where it is 0.965 at 500 °C and 0.952 at 600 °C.

[0044] Example 2

[0045] The preparation method of the high - infrared emissivity perovskite - type ceramic material in this example includes the following steps:

[0046] Step (1): Sr(NO3)2, Zn(CH3COO)2, and Zr(C2H3O2)4 are added to deionized water which is 4 times the total mass of Sr(NO3)2, Zn(CH3COO)2, and Zr(C2H3O2)4 according to the molar ratio of 1:0.25:0.75, and heated in a water bath at 50 °C and stirred thoroughly for 1 h to obtain a uniformly mixed mixture A;

[0047] Step (2): Under the condition of a 60 °C water bath, citric acid is added to the mixture A and stirred for another 1.5 h to obtain a mixture B. The molar ratio of the added citric acid to the total molar amount of cations in the mixture A is 1:1.4;

[0048] Step (3): Under the condition of a 90 °C water bath, ammonia water is added drop - by - drop to the mixture B and stirred for 2 h to obtain a mixture C; when the pH of the mixture C reaches 9, the addition of ammonia water is stopped, and the ammonia water is added drop - by - drop within 28 min, and the mass concentration of the ammonia water is 26 wt%;

[0049] Step (4): The mixture C is dried at 120 °C for 18 h to remove moisture, and the dried product obtained after drying is ground in an agate mortar for 1.5 h to obtain a precursor powder; the particle size of the precursor powder is 56 - 98 μm;

[0050] Step (5): The precursor powder is poured into a zirconia crucible to make the powder evenly distributed in the crucible, and the crucible is placed in a muffle furnace for atmospheric pressure sintering; the sintering conditions for the precursor powder under atmospheric pressure are: heating at a heating rate of 4 °C / min to 300 °C and holding for 4 h; then heating at a heating rate of 4 °C / min to 600 °C and holding for 4 h; then heating to 1200 °C at a heating rate of 4 °C / min and holding for 4 h; finally, it is naturally cooled to room temperature, and the high - infrared emissivity perovskite - type ceramic material is prepared.

[0051] The molecular formula of the finally prepared high - infrared emissivity perovskite - type ceramic material in this example is Sr(Zr 0.75 Zn 0.25 )O 2.75. After testing, the Sr(Zr 0.75 Zn 0.25 )O 2.75 ceramic powder within the temperature range of room temperature to 600 °C: the infrared emissivity in the 3 - 5 μm band is 0.903 - 0.958, where it is 0.958 at 600 °C; the infrared emissivity in the 1 - 22 μm band is 0.843 - 0.955, where it is 0.955 at 500 °C and 0.923 at 600 °C.

[0052] Example 3

[0053] The preparation method of the perovskite - type ceramic material with high infrared emissivity in this example includes the following steps:

[0054] Step (1), Sr(NO3)2, Mn(CH3COO)2, and Zr(C2H3O2)4 are added to deionized water which is 5 times the total mass of Sr(NO3)2, Mn(CH3COO)2, and Zr(C2H3O2)4 according to the molar ratio of 1:0.1875:0.8125, and heated in a water bath at 55 °C with full stirring for 1 h to obtain a uniformly mixed mixture A;

[0055] Step (2), under the condition of a 70 °C water bath, citric acid is added to the mixture A and stirred for another 1 h to obtain a mixture B. The molar ratio of the added citric acid to the total molar amount of cations in the mixture A is 1:1.5;

[0056] Step (3), under the condition of a 95 °C water bath, ammonia water is added drop - by - drop to the mixture B and stirred for 2 h to obtain a mixture C; when the pH of the mixture C reaches 9, the addition of ammonia water is stopped, and the ammonia water is added drop - by - drop within 28 min, and the mass concentration of the ammonia water is 26 wt%;

[0057] Step (4), the mixture C is dried at 120 °C for 24 h to remove moisture, and the dried product is ground in an agate mortar for 1.5 h to obtain a precursor powder; the particle size of the precursor powder is 54 - 94 μm;

[0058] Step (5), the precursor powder is poured into a zirconia crucible to make the powder evenly distributed in the crucible, and the crucible is placed in a muffle furnace for atmospheric sintering; the sintering conditions for the precursor powder under atmospheric pressure are: heating at a heating rate of 3 °C / min to 300 °C and holding for 2 h; then heating at a heating rate of 3 °C / min to 600 °C and holding for 2 h; then heating to 1400 °C at a heating rate of 3 °C / min and holding for 6 h; finally, it is naturally cooled to room temperature, and the perovskite - type ceramic material with high infrared emissivity is prepared.

[0059] The molecular formula of the perovskite-type ceramic material with high infrared emissivity finally prepared in this embodiment is Sr(Zr 0.1875 Mn 0.8127 )O 2.8125 . After testing, for the Sr(Zr 0.1875 Mn 0.8127 )O 2.8125 ceramic powder within the range of room temperature to 600 °C: the infrared emissivity in the 3 - 5 μm band is 0.853 - 0.955, where it is 0.955 at 600 °C; the infrared emissivity in the 1 - 22 μm band is 0.873 - 0.951, where it is 0.951 at 500 °C and 0.943 at 600 °C.

[0060] Figure 2 XRD patterns of the Sr(Zr 1-y X y )O z ceramic powders prepared in Examples 1 - 3 and the relevant standard diffraction patterns. As can be seen from Figure 2 , the Sr(Zr 1-y X y )O z ceramic powders prepared in Examples 1 - 3 are all single orthorhombic SrZrO3 phase, indicating that the preparation method in the present invention can successfully prepare the perovskite orthorhombic Sr(Zr 1-y X y )O z ceramic powder.

[0061] Obviously, the above examples are only illustrations given for clear explanation and are not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or alterations can be made based on the above description. It is not necessary and impossible to list all the implementation manners here. And the obvious changes or alterations derived therefrom are still within the protection scope of the claims of this patent application.

Claims

1. Application of a perovskite-type ceramic material with high infrared emissivity, characterized in that, The perovskite ceramic material with high infrared emissivity is used as the inner lining material of a high-temperature sintering furnace or as the radiation heat dissipation material for high-power optical and electronic devices; The molecular formula of the high-infrared emissivity perovskite-type ceramic material is Sr(Zr 1-y X y )O z , where X is Mg, Ca, Mn, Fe, Co, Ni, Cu or Zn.

2. The application of the perovskite-type ceramic material with high infrared emissivity according to claim 1, characterized in that, The value range of y is 0.05 to 0.5, and the value range of z is 2.5 to 2.9375.

3. The application of the perovskite-type ceramic material with high infrared emissivity according to claim 1, characterized in that, A preparation method of a perovskite ceramic material with high infrared emissivity, comprising the following steps: Step (1): Add a water-soluble strontium salt, a water-soluble X salt, and a water-soluble zirconium salt to deionized water, carry out water bath heating, and stir well to dissolve to obtain a mixed system A; Step (2): Under the water bath condition, add citric acid to the mixed system A and continue to stir to obtain a mixed system B; Step (3): Under the water bath condition, gradually add ammonia water dropwise to the mixed system B and continue to stir to obtain a mixed system C; Step (4): Dry and bake the mixed system C, and grind the dried product to obtain a precursor powder; Step (5): Sinter the precursor powder under normal pressure, and after the sintering is completed, the perovskite ceramic material with high infrared emissivity is prepared.

4. Use of the perovskite-type ceramic material with high infrared emissivity according to claim 3, characterized in that, In step (1), the water-soluble strontium salt is one or a mixture of two or more of strontium acetate, strontium nitrate, and strontium bromide; the water-soluble X salt is one or a mixture of two or more of magnesium acetate, magnesium chloride, calcium acetate monohydrate, calcium chloride hexahydrate, manganese acetate, manganese chloride, manganese nitrate, iron nitrate nonahydrate, iron trichloride, cobalt chloride hexahydrate, cobalt acetate tetrahydrate, nickel acetate tetrahydrate, nickel chloride hexahydrate, copper nitrate trihydrate, copper acetate, copper chloride, zinc acetate, and zinc chloride; the water-soluble zirconium salt is one or a mixture of two or more of zirconyl chloride, zirconyl nitrate, or zirconium acetate; In step (1), in the mixed system A: the molar ratio of strontium ions, X ions, and zirconium ions is (1 to 1.3): (0.05 to 0.5): (0.5 to 0.95); the total mass ratio of the water-soluble strontium salt, the water-soluble X salt, and the water-soluble zirconium salt to the mass of deionized water is 1: (3 to 8); the water bath heating temperature is 40 to 60 °C, and the water bath heating and stirring time is 1 to 1.5 h.

5. The application of the perovskite-type ceramic material with high infrared emissivity according to claim 3, characterized in that, In step (2), the molar ratio of the added citric acid to the total molar amount of cations in the mixed system A is 1: (1.2 to 2); the water bath heating temperature is 50 to 70 °C, and the water bath heating and stirring time is 1 to 1.5 h.

6. The application of the perovskite-type ceramic material with high infrared emissivity according to claim 3, characterized in that, In step (3), the addition amount of ammonia water is based on making the pH of the mixed system C between 8 and 10, the ammonia water is added dropwise within 15 to 30 minutes, the mass concentration of the ammonia water is 25 to 28 wt%; the water bath heating temperature is 80 to 95 °C, and the water bath heating and stirring time is 1.5 to 2 h.

7. Use of the perovskite-type ceramic material with high infrared emissivity according to claim 3, characterized in that, In step (4), the drying temperature is 120 °C, the drying time is 12 to 24 h, the grinding time of the dried product is 1 to 1.5 h, and the particle size of the precursor powder is 50 to 100 μm.

8. The application of the perovskite-type ceramic material with high infrared emissivity according to claim 3, wherein In step (5), the sintering conditions for the precursor powder sintered under atmospheric pressure are as follows: heating up to 300 °C at a heating rate of 3 - 5 °C / min and holding for 2 - 5 h; then heating up to 600 °C at a heating rate of 3 - 5 °C / min and holding for 2 - 5 h; then heating up to 1000 °C - 1600 °C at a heating rate of 3 - 10 °C / min and holding for 3 - 6 h; finally, cooling naturally to room temperature.

9. Use of the perovskite-type ceramic material with high infrared emissivity according to any one of claims 3-8, characterized in that In step (1), the water-soluble strontium salt is strontium nitrate; the water-soluble X salt is copper nitrate trihydrate; the water-soluble zirconium salt is zirconium acetate; in the mixed system A, the molar ratio of strontium ions, X ions and zirconium ions is 1:0.375:0.625; the ratio of the total mass of the water-soluble strontium salt, the water-soluble X salt and the water-soluble zirconium salt to the mass of deionized water is 1:4; the water bath heating temperature is 50 °C and the water bath heating stirring time is 1 h; In step (2), the molar ratio of the amount of citric acid added to the total amount of cations in the mixed system A is 1:1.2; the water bath heating temperature is 50 °C and the water bath heating stirring time is 1 h; In step (3), the addition of ammonia water is stopped when the pH of the mixed system C is 10. The ammonia water is added dropwise within 30 min, and the mass concentration of the ammonia water is 26 wt%; the water bath heating temperature is 80 °C and the water bath heating stirring time is 1.5 h; In step (4), the drying temperature is 120 °C, the drying time is 12 h, the grinding time of the dried product is 1 h, and the particle size of the precursor powder is 60 - 100 μm; In step (5), the sintering conditions for the precursor powder sintered under atmospheric pressure are as follows: heating up to 300 °C at a heating rate of 3 °C / min and holding for 2 h; then heating up to 600 °C at a heating rate of 3 °C / min and holding for 2 h; then heating up to 1000 °C at a heating rate of 3 °C / min and holding for 6 h; finally, cooling naturally to room temperature.

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