CN110818409B

CN110818409B - Preparation of SrZrO3And SrZrO3Ceramic material

Info

Publication number: CN110818409B
Application number: CN201911352481.1A
Authority: CN
Inventors: 王俊; 马小波; 于浩洋; 孟祥博; 马文; 新巴雅尔
Original assignee: Inner Mongolia University of Technology
Current assignee: Inner Mongolia University of Technology
Priority date: 2019-12-25
Filing date: 2019-12-25
Publication date: 2022-03-08
Anticipated expiration: 2039-12-25
Also published as: CN110818409A

Abstract

The invention provides a method for preparing SrZrO ₃ . The preparation method includes mixing SrCO ₃ and ZrO ₂ , pressing into a compact and then placing it in a microwave environment for treatment. The treatment includes powder treatment or block treatment. The powder treatment is heated to 1100-1400 ℃, heat preservation for not less than 30min, to obtain SrZrO ₃ powder; for block treatment, add powder to bury and sinter, heat up to 1200-1650 ℃ for sintering at a rate of 5-25 ℃/min, and keep the temperature for not less than 30min, SrZrO ₃ bulk was obtained. The SrZrO ₃ block prepared by the invention has excellent characteristics such as good chemical stability, mechanical strength and high temperature sintering resistance, so that it can be used as military weapons such as aircraft tanks with low emissivity, low thermal conductivity, high expansion coefficient and high temperature resistance. Infrared stealth skin material. Meanwhile, the present application also provides a SrZrO ₃ ceramic prepared by the above method.

Description

Preparation of SrZrO3And SrZrO3Ceramic material

Technical Field

The invention relates to the technical field of ceramic preparation, and particularly relates to a method for preparing SrZrO₃And SrZrO₃A ceramic.

Background

With the development of modern military detection technology and guidance technology, the importance of stealth technology in modern information war is increasing day by day. Infrared detection technology is an important auxiliary means of radar detection technology and occupies an irreplaceable position in modern war. The infrared imaging distance, precision, concealment and anti-interference performance all have strong advantages, and the infrared imaging method is widely applied in military affairs. The infrared radiation characteristic signals of the target are weakened by means of coating on the surface of the target and the like, so that the probability of finding and identifying the target is effectively reduced, and the battlefield viability of the target is improved. However, the existing skin material of military weapons is not enough to meet the use requirements in the aspects of infrared emissivity, thermal conductivity, expansion coefficient and high temperature resistance.

Disclosure of Invention

The invention provides a method for preparing SrZrO₃To improve the above technical problems.

The invention achieves the above object by the following technical solutions.

In a first aspect, the embodiment of the invention provides SrZrO preparation₃The method comprises mixing SrCO₃And ZrO₂Mixing, pressing into blank, and treating in microwave environment, wherein the treatment comprises powder treatment or block treatment, the powder treatment comprises heating to 1100-₃Powder; the block is treated by adding powder for burning, heating to 1200-1650 ℃ at the speed of 5-25 ℃/min for sintering, and keeping the temperature for not less than 30min to obtain SrZrO₃And (3) a block body.

In some embodiments, the powder processing further comprises: the SrZrO₃Adding powder into the powder for burning, heating to 1200-1650 ℃ at the speed of 5-25 ℃/min for sintering,keeping the temperature for not less than 30min to obtain SrZrO₃And (3) a block body.

In a second aspect, embodiments of the present invention provide a SrZrO₃Ceramics prepared by the above preparation method.

The invention relates to microwave preparation and sintered SrZrO₃Is a perovskite (ABO)₃) The advanced ceramic material of the structure has higher thermal expansion coefficient and lower thermal conductivity. Meanwhile, the material has the excellent characteristics of good chemical stability, mechanical strength, high-temperature sintering resistance and the like, and can be used as a stealth skin material for military weapons such as airplane tanks and the like with low emissivity, low thermal conductivity, high expansion coefficient and high temperature resistance.

These and other aspects of the invention are apparent from and will be elucidated with reference to the embodiments described hereinafter.

Drawings

FIG. 1 shows SrZrO obtained in comparative Experimental example 1 of the present invention₃X-ray diffraction pattern of the mass.

FIG. 2 shows SrZrO obtained in comparative Experimental example 1 of the present invention₃SEM image of the bulk.

FIG. 3 shows SrZrO obtained in comparative Experimental example 2 of the present invention₃X-ray diffraction pattern of the powder.

FIG. 4 shows SrZrO obtained in comparative Experimental example 2 of the present invention₃SEM image of powder.

FIG. 5 shows SrZrO obtained in comparative Experimental example 3 of the present invention₃X-ray diffraction pattern of the mass.

FIG. 6 shows SrZrO obtained in comparative Experimental example 3 of the present invention₃SEM image of the bulk.

FIG. 7 is a graph showing the thermal diffusivity of the present invention obtained in comparative experiment example 3.

Fig. 8 is a graph of the thermal conductivity obtained in comparative experimental example 3 of the present invention.

FIG. 9 is a graph showing infrared scattering ratios obtained in comparative experiment example 3 of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.

Strontium zirconate (SrZrO)₃) Is a common ceramic, and is currently used for SrZrO₃Most of ceramic sintering technologies are limited to muffle furnace high-temperature sintering, and the sintering temperature is mostly concentrated near 1600 ℃, and the high-temperature solid phase method has the disadvantage of slow temperature rise and fall rate (temperature rise rate:<10 ℃/min, above 1400 DEG C<5 ℃/min, above 1600 DEG C<2 ℃/min; cooling rate:<5 ℃/min) and longer heat preservation time (6-24 h). Therefore, 15-30h is needed in one cycle in the firing process, and the energy consumption is huge due to the overlong cycle. Accordingly, the inventors of the present application have proposed SrZrO in the present application₃The preparation method of (1).

The microwave sintering furnace has fast temperature rise and fall rate (the low temperature stage is 20-100 ℃/min, the high temperature stage is 10-50 ℃/min, the temperature reduction rate is 5-10 ℃/min within the power allowable range), the sintering period is about 3-8h which is 1/3-1/4 times of the muffle furnace sintering period, thus greatly saving resources, reducing cost and being very beneficial to environmental protection.

In a first aspect, the embodiments of the present application provide a method for preparing SrZrO₃The method comprises the following steps: mixing SrCO₃And ZrO₂Mixing, pressing into blank, and treating in microwave environment.

The treatment comprises powder treatment or block treatment, wherein the powder treatment comprises heating to 1100 ℃ and 1400 ℃, and preserving heat for not less than 30min to obtain SrZrO₃And (3) powder.

Wherein SrCO₃And ZrO₂Can be (1-1.1) to (0.9-1), for example in some embodiments, SrCO₃And ZrO₂The molar ratio of the starting materials of (a) may be 1.12: 0.91, 1.1:0.9, etc. In some embodiments, more preferably, SrCO₃And ZrO₂The molar ratio of the raw materials of (1:0.99) - (1:0.9), or SrCO₃And ZrO₂The molar ratio of the raw materials of (1.1: 0.9) to (1.1:1) may be used. Of course, it will be understood that the otherIn some embodiments, SrCO₃And ZrO₂The molar ratio of the raw materials (C) may be other values. Mixing SrCO₃And ZrO₂Is set to be approximately 1:1, ensuring SrCO₃The content of (A) is slightly larger than ZrO₂The purpose is to supplement SrCO₃Loss due to unstable decomposition during high temperature. On one hand, the reaction can be promoted, and simultaneously, the utilization rate of the raw materials is improved, thereby being beneficial to controlling the finally generated SrZrO₃The content of impurities in the product. As an example, SrCO₃And ZrO₂The molar ratio of the raw materials (A) may be 1:0.9, 1:0.92, 1:0.94, 1:0.96, 1:0.98, etc., or 1.2:1, 1.4:1, 1.6:1, 1.8:1, 1.2:0.92, 1.4:0.96, 1.2:0.98, etc., and they are not illustrated herein.

The pressing to form the blank refers to that the raw materials are mixed and then are pressed to form the blank so as to increase the density of the blank. The pressing into a blank may be carried out in the following manner:

in some embodiments, SrCO may be used₃And ZrO₂The mixture is pressed into a blank under a pressure of 4-25MPa, such as 8-20MPa, 10-15MPa, etc., specifically, the pressure of the pressed blank is 4MPa, 6MPa, 8MPa, 10MPa, 15MPa, 18MPa, 20MPa, 22MPa, 25MPa, etc. In some embodiments, the SrCO is₃And ZrO₂The mixture is pressed into a blank under the isostatic pressure environment at the pressure of more than or equal to 25MPa, wherein the isostatic pressure treatment can be realized in an isostatic press, and the isostatic pressure treatment can realize more uniform pressure pressing and improve the uniformity of the blank. The isostatic pressing may be performed, for example, at a pressure of 8 to 20MPa, 10 to 15MPa, or the like, and specifically, the pressure for pressing the green body may be 4MPa, 6MPa, 8MPa, 10MPa, 15MPa, 18MPa, 20MPa, 22MPa, 25MPa, or the like. In some embodiments, SrCO may also be preceded₃And ZrO₂The mixture is pressed into a blank for the first time under the pressure of 4-25Mpa, and then the blank is pressed into a blank for the second time under the isostatic pressure environment, and the pressure of the second pressing is greater than that of the first pressing, so that a blank body is formed. The pressure of the second pressing may be, for example, 25MPa or more, for example, 25MPa, 30MPa, 35MPa or more.

The microwave environment can be provided by a microwave sintering furnace and other equipment, and specifically, during sintering, the semi-finished product pressed into a blank is added into the microwave sintering furnace for sintering. The microwave sintering furnace has high temperature rise and fall rate, so that the temperature rise period can be greatly shortened, and the energy consumption is reduced.

Wherein SrCO is mixed₃And ZrO₂The temperature of the mixture is raised to 1100-.

In some embodiments, in the above method, when the powder treatment is performed, SrZrO is prepared₃After the powder is prepared, SrZrO can be further prepared₃And (3) a block body. Specifically, it may be performed in the following manner: the SrZrO₃Pressing the powder into a blank, adding the powder to be buried and sintered, heating to 1200-1650 ℃ at the speed of 5-25 ℃/min, and preserving the heat for not less than 30min to obtain SrZrO₃And (3) a block body.

SrZrO obtained by the above method₃Pressing the powder into a green body, and sintering to obtain the final SrZrO₃Ceramic block, SrZrO obtained in this way₃The ceramic block has a longer total sintering time and thus better chemical stability and mechanical strength. In the above embodiment, SrZrO is formed₃The powder is sintered once and then pressed into a blank again, and then the sintering operation of powder burial is matched to obtain SrZrO₃And (3) a block body. Note that, the pressing and blank forming operation and the sintering operation may refer to the foregoing embodiments, and are not limited herein.

The powder is added for burning, mainly aiming at isolating a blank body from air on the premise of not introducing impurities, reducing the generation of side reaction, and simultaneously being beneficial to maintaining the temperature in the sintering process so as to ensure that the blank body is heated uniformly. Quickening the sintering process and further saving energy consumption. Experiments prove that ZrO₂And Al₂O₃At least one of the powder can meet the requirement, and other auxiliary powder can be used in the actual production. For example, ZrO may be used alone₂As the powder, it is also possible to use aloneWith Al₂O₃As the powder, ZrO may be used₂And Al₂O₃The mixture of (a) is buried and burned as powder. When ZrO is used₂And Al₂O₃When the mixture of (A) and (B) is used as a powder, ZrO₂And Al₂O₃The molar ratio of (b) may be, for example, 1:1, 2:1, 1:2, etc.

And during sintering, controlling the temperature rise rate to be 5-25 ℃/min, and finally heating to 1200-1650 ℃ for sintering, wherein the heat preservation time during sintering is not less than 30min, for example, 30min-6h, 6-8h and the like, specifically, the heat preservation time is, for example, 30min, 1h, 1.5h, 2h, 3h, 4h, 5h, 6h and the like. Wherein, the holding time refers to holding the sintering temperature for a period of time after the temperature is raised to the sintering temperature. In this time frame, it is already possible to ensure that the sintered ceramic mass has a high coefficient of thermal expansion and a low thermal conductivity. Meanwhile, the material has the excellent characteristics of good chemical stability, mechanical strength, high-temperature sintering resistance and the like, and accordingly, the energy consumption is correspondingly increased by increasing the sintering time, and the production cost is not reduced. Of course, it is understood that in some embodiments, the incubation time may also continue to be increased. In a preferred embodiment, the sintering temperature may be 1300 ℃ to 1500 ℃, for example 1350 ℃, 1400 ℃ to 1450 ℃, and the temperature increase rate may be, for example, 5 to 10 ℃/min, for example, 5 ℃/min, 6 ℃/min, 7 ℃/min, 9 ℃/min, etc., or 10 to 20 ℃/min, for example, 10 ℃/min, 12 ℃/min, 14 ℃/min, 16 ℃/min, 18 ℃/min, etc., or 20 to 25 ℃/min, for example, 23 ℃/min, 25 ℃/min, etc.

The block is treated directly after SrCO₃And ZrO₂Mixing, pressing into blank, placing in microwave environment, adding powder, calcining, heating to 1200-1650 deg.C at 5-25 deg.C/min, and maintaining for at least 30min to obtain SrZrO₃And (3) a block body.

Wherein the powder is added in the processes of burying, sintering and the SrZrO₃Preparation of SrZrO from powder₃The process of the block is similar. In particular, direct compression of green SrCO₃And ZrO₂Adding powder into the mixture, heating to 1200-165 ℃ at the speed of 5-25 ℃/minSintering at 0 deg.C for at least 30min to obtain SrZrO₃And (3) a block body. The types of the powder, the heating rate, the sintering temperature, the heat preservation time, and the like can be referred to the above, and are not described herein again.

In a second aspect, an embodiment of the present application further provides SrZrO₃Ceramics, which can be produced by the above-mentioned production method, wherein SrZrO₃Can be a powder, in some embodiments, SrZrO₃Or may be a block. SrZrO provided by the embodiment₃The powder can be used as a skin material of military equipment, and can be formed on the surface of the military equipment in a spraying mode.

As an example, SrZrO prepared by the above method₃The melting point of the ceramic block is approximately 2650 ℃, and the ceramic block has a high thermal expansion coefficient [ (8.7-10.8) multiplied by 10%^-6/K(200-1100℃)]And a relatively low thermal conductivity [ (2.1-3.3) W/(m.K) (200 ℃.)]Meanwhile, the material has the excellent characteristics of good chemical stability, mechanical strength, high-temperature sintering resistance and the like, and can be used as an infrared stealth skin material for military weapons such as airplane tanks and the like with low emissivity, low thermal conductivity, high expansion coefficient and high temperature resistance.

The preparation of SrZrO according to the present invention will be described with reference to the following specific examples₃And SrZrO thereof₃The method of the block is described in further detail.

Example 1:

using SrCO₃And ZrO₂In terms of n (SrCO)₃)：n(ZrO₂) The raw materials were mixed well in a molar ratio of 1.02: 0.98. Well mixed SrCO₃And ZrO₂The powder is pressed into a blank by a tablet press under the pressure of 8 Mpa.

Placing the green body into a microwave sintering furnace, and using ZrO to uniformly heat the green body₂Or Al₂O₃The powder is buried and sintered at 1400 ℃, the heating rate is 10 ℃/min, the heat preservation time is 30min, and the final SrZrO is obtained₃A ceramic block.

Example 2:

using SrCO₃And ZrO₂In terms of n (SrCO)₃)：n(ZrO₂) Thoroughly mixing the raw materials in a molar ratio of 1.04: 0.96; well mixed SrCO₃And ZrO₂The powder is pressed into a blank by a tablet press under the pressure of 10 Mpa.

Placing the green body into a microwave sintering furnace, and using ZrO to uniformly heat the green body₂Or Al₂O₃The powder is buried and burned, the sintering temperature is 1500 ℃, the heating rate is 15 ℃/min, the heat preservation time is 1h, and the final SrZrO is obtained₃A ceramic block.

Example 3:

using SrCO₃And ZrO₂In terms of n (SrCO)₃)：n(ZrO₂) Fully mixing the raw materials in a molar ratio of 1.02: 0.98; mixing well SrCO₃And ZrO₂The powder was placed in an isostatic press and pressed to a blank using a pressure of 25 Mpa.

Placing the green body into a microwave sintering furnace, and ZrO₂Or Al₂O₃The powder is subjected to auxiliary embedding burning, the sintering temperature is 1500 ℃, the heating rate is 15 ℃/min, the heat preservation time is 30min, and the final SrZrO is obtained₃A ceramic block.

Example 4:

using SrCO₃And ZrO₂According to n (SrCO)₃)：n(ZrO₂) Thoroughly mixing the raw materials in a molar ratio of 1.04: 0.96; and putting the mixed SrCO3 and ZrO2 powder into isostatic pressing, and pressing into a blank by using the pressure of 30 Mpa.

Placing the green body into a microwave sintering furnace, and ZrO₂Or Al₂O₃The powder is subjected to auxiliary embedding burning, the sintering temperature is 1400 ℃, the heating rate is 20 ℃/min, the heat preservation time is 1h, and the final SrZrO is obtained₃A ceramic block.

Example 5:

using SrCO₃And ZrO₂According to n (SrCO)₃)：n(ZrO₂) The raw materials were mixed well in a molar ratio of 1.02: 0.98.

And pressing the fully mixed raw material powder into a blank by using a tablet press under the pressure of 8Mpa, placing the pressed blank into isostatic pressing, and performing secondary pressurization by using the pressure of 35Mpa which is higher than that of the tablet press to ensure that the blank is combined more compactly.

Placing the compact uniform raw material blank in a microwave sintering furnace, and ZrO₂Or Al₂O₃The powder is subjected to auxiliary embedding burning, the sintering temperature is 1400 ℃, the heating rate is 15 ℃/min, the heat preservation time is 1h, and the final SrZrO is obtained₃A ceramic block.

Example 6:

using SrCO₃And ZrO₂According to n (SrCO)₃)：n(ZrO₂) The raw materials were mixed well in a molar ratio of 1.04: 0.96.

And pressing the fully mixed raw material powder into a blank by using a tablet press under the pressure of 12Mpa, placing the pressed blank into isostatic pressing, and performing secondary pressurization by using the pressure of more than 30Mpa of the tablet press to ensure that the blank is combined more compactly.

Pressing compact uniform raw material blank, placing in microwave sintering furnace, using ZrO₂Or Al₂O₃The powder is subjected to auxiliary embedding burning, the sintering temperature is 1500 ℃, the heating rate is 20 ℃/min, the heat preservation time is 30min, and the final SrZrO is obtained₃A ceramic block.

Example 7:

using SrCO₃And ZrO₂According to n (SrCO)₃)：n(ZrO₂) Fully mixing the raw materials at a molar ratio of 1.02:0.98, heating the mixed raw materials to 1200 ℃ in a microwave sintering furnace, and keeping the temperature for 1h to obtain SrZrO₃And (3) powder.

SrZrO 2₃Pressing the powder into a blank under the pressure of 10Mpa by using a tablet press, placing the blank in a microwave sintering furnace, and at the moment, in order to uniformly heat the ceramic block, still using ZrO₂Or Al₂O₃And (5) embedding and burning the powder in an auxiliary way. The sintering temperature is 1350 ℃, the heating rate is 15 ℃/min, the heat preservation time is 2h, and the final SrZrO is obtained₃A ceramic block.

Example 8:

using SrCO₃And ZrO₂According to n (SrCO)₃)：n(ZrO₂) Mixing the raw materials at a molar ratio of 1.04:0.96, heating the mixed raw materials to 1300 ℃ in a microwave sintering furnaceThe temperature and the time are 2h, and SrZrO is obtained₃And (3) powder.

SrZrO 2₃Pressing the powder into a blank under the pressure of 12Mpa by using a tablet press, placing the blank in a microwave sintering furnace, and at the moment, in order to uniformly heat the ceramic block, still using ZrO₂Or Al₂O₃And (5) embedding and burning the powder in an auxiliary way. The sintering temperature is 1400 ℃, the heating rate is 10 ℃/min, the heat preservation time is 3h, and the final SrZrO is obtained₃A ceramic block.

Example 9:

using SrCO₃And ZrO₂According to n (SrCO)₃)：n(ZrO₂) Fully mixing the raw materials in a molar ratio of 1.02:0.98, heating the mixed raw materials to 1250 ℃ in a microwave sintering furnace, and keeping the temperature for 1h to obtain SrZrO₃And (3) powder. Using isostatic pressing at 25MPa to form SrZrO₃Pressing the powder into a blank.

Placing the green body in a microwave sintering furnace, and using ZrO₂Or Al₂O₃And (5) embedding and burning the powder in an auxiliary way. The sintering temperature is 1500 ℃, the heating rate is 20 ℃/min, the heat preservation time is 30min, and the final SrZrO is obtained₃A ceramic block.

Example 10:

using SrCO₃And ZrO₂According to n (SrCO)₃)：n(ZrO₂) Fully mixing the raw materials according to the molar ratio of 1.04:0.96, heating the mixed raw materials to 1300 ℃ in a microwave sintering furnace, and keeping the temperature for 2 hours to obtain SrZrO₃Powder prepared by isostatic pressing SrZrO under 30MPa₃Pressing the powder into a blank.

Placing the green body in a microwave sintering furnace, and using ZrO₂Or Al₂O₃And (5) embedding and burning the powder in an auxiliary way. The sintering temperature is 1400 ℃, the heating rate is 15 ℃/min, the heat preservation time is 1h, and the final SrZrO is obtained₃A ceramic block.

Example 11:

using SrCO₃And ZrO₂According to n (SrCO)₃)：n(ZrO₂) The raw materials are fully mixed according to the molar ratio of 1.04:0.96, and the mixed raw materials are heated in a microwave sintering furnace to a temperature ofKeeping the temperature at 1200 ℃ for 2h to obtain SrZrO₃And (3) powder.

Prepared SrZrO₃The powder is pressed into a blank by a tablet press under the pressure of 12Mpa, the pressed blank is placed in isostatic pressure, and secondary pressurization is carried out by the pressure of 30Mpa, so that the blank is combined more compactly.

Placing the finally obtained blank in a microwave sintering furnace, and using ZrO₂Or Al₂O₃The powder is subjected to auxiliary embedding burning, the sintering temperature is 1400 ℃, the heating rate is 20 ℃/min, the heat preservation time is 2h, and the final SrZrO is obtained₃A ceramic block.

Example 12:

using SrCO₃And ZrO₂According to n (SrCO)₃)：n(ZrO₂) Mixing the raw materials at a molar ratio of 1.02:0.98, heating the mixed raw materials to 1350 ℃ in a microwave sintering furnace, and keeping the temperature for 1h to obtain SrZrO₃Powder;

prepared SrZrO₃And pressing the powder into a blank by using a tablet press under the pressure of 10Mpa, putting the pressed blank into isostatic pressing, and performing secondary pressing by using the pressure of 35Mpa to ensure that the blank is combined more compactly.

Placing the finally obtained blank in a microwave sintering furnace, and using ZrO₂Or Al₂O₃The powder is subjected to auxiliary embedding burning, the sintering temperature is 1350 ℃, the heating rate is 15 ℃/min, the heat preservation time is 1h, and the final SrZrO is obtained₃A ceramic block.

Comparative Experimental example 1

SrZrO was obtained in the manner described in example one₃ Sample 1 was obtained without powder-embedding treatment in the ceramic block. Taking SrZrO obtained in example one₃The ceramic block is used as a sample 2, and the sample 1 and the sample 2 are subjected to an X-ray diffraction test, wherein the test instrument is an X-ray powder diffractometer. The diffraction pattern obtained by the test is shown in FIG. 1, wherein it can be seen from FIG. 1 that ZrO was used₂SrZrO obtained by powder burial treatment₃The ceramic block has obviously higher strength value in X-ray diffraction, which shows that the powder burying treatment can obviously improve the sintering generation of SrZrO₃Of ceramic blocksConversion and SrZrO₃Chemical stability of the ceramic block.

The SEM images obtained by the SEM tests of

samples

1 and 2 are shown in FIG. 2, and it can be seen from FIG. 2 that SrZrO obtained by the method of the embodiment of the present application₃The ceramic block has compact structure and excellent high temperature sintering resistance.

Comparative experiment example 2

Using SrCO₃And ZrO₂According to n (SrCO)₃)：n(ZrO₂) Fully mixing the raw materials at a molar ratio of 1.02:0.98, heating the mixed raw materials in a microwave sintering furnace for 1h to obtain SrZrO₃Powder sample 3 and sample 4. Wherein sample 3 and sample 4 differ in that the heating temperature for sample 3 is 1200 c and the heating temperature for sample 4 is 1300 c.

The X-ray diffraction test was performed on samples 3 and 4, and the test apparatus was an X-ray powder diffractometer. The diffraction pattern obtained from the test is shown in fig. 3, where it can be seen from fig. 3 that the sintering temperature of sample 4 is higher than that of sample 3, and the intensity values in X-ray diffraction are significantly higher, indicating that heating to 1300 ℃ can significantly improve the formation of SrZrO as compared to heating to 1200 ℃ alone₃Chemical stability of the powder.

The SEM images obtained by testing samples 3 and 4 by scanning electron microscopy are shown in FIG. 4, and FIG. 4 shows the SrZrO obtained₃SEM image of the powder, it can be seen that SrZrO was obtained₃The powder has compact structure and moderate particle size, and is suitable for being applied to processes such as spraying and the like to form the skin material.

Comparative experiment example 3

SrZrO 2₃Pressing the powder into a blank under the pressure of 10Mpa by using a tablet press, placing the blank in a microwave sintering furnace, and at the moment, in order to uniformly heat the ceramic block, still using ZrO₂Or Al₂O₃And (5) embedding and burning the powder in an auxiliary way. Heating and sintering, wherein the heating rate is 15 ℃/min, the heat preservation time is 2h, and the final SrZrO is obtained₃ Ceramic block samples 5, 6, 7, 8, 9, 10. Wherein the samples 5, 6, 7, 8, 9 and 10 are distinguished in that the sintering temperature is 1200 ℃, 1250 ℃, 1350 ℃, 1400 ℃, 1450 ℃ and 1500 ℃ in sequence.

And (3) carrying out an X-ray diffraction test on the samples 5-10, wherein the test instrument is an X-ray powder diffractometer. The diffraction pattern obtained by the test is shown in fig. 3, wherein it can be seen from fig. 3 that the higher the sintering temperature is, the higher the intensity value in X-ray diffraction is, indicating that the sintering temperature is increased, and the formation of SrZrO can be improved significantly₃The chemical stability of the block body, but the energy consumption is correspondingly increased by increasing the sintering temperature, and the SrZrO sintered under the conditions of 1200-1600 DEG C₃All the parameter indexes of the block body can meet good use characteristics.

Scanning electron microscope testing of samples 5-10 resulted in SEM images as shown in FIG. 6, and comparing FIGS. 6 and 2, it can be seen that SrZrO was obtained first₃Powder of SrZrO₃SrZrO obtained by powder burial firing of powder₃The structure of the block is compared with that of the SrZrO directly sintered₃The block is more compact, so that the high-temperature resistance of the block can be more remarkably enhanced.

The thermal diffusion coefficient (thermal diffusion) value of samples 7-10 was measured, and the measured value is shown in FIG. 7, wherein the curves from top to bottom in FIG. 7 are sample 8, sample 10, sample 9 and sample 7, and it can be seen that the SrZrO obtained under the condition of 1400 ℃ and 1500 ℃₃The thermal diffusivity of the block is high, and particularly when the block is sintered at 1400 ℃, the obtained SrZrO₃The thermal diffusivity of the block is highest.

Thermal conductivity (thermal conductivity) values were measured for samples 7-10, and the measured values are shown in FIG. 8, wherein the curves from top to bottom in FIG. 8 are, in order, sample 8, sample 10, sample 7 and sample 9, wherein it can be seen from FIG. 8 that when the temperature exceeded 700 deg.C, the thermal conductivity of sample 9 was higher than that of sample 7, thus indicating that SrZrO was obtained at 1400-1500 deg.C₃The thermal conductivity of the block is highSrZrO obtained, in particular when sintering is carried out at 1400 DEG C₃The thermal conductivity of the block is highest.

The infrared emissivity (infrared emissivity) values of the samples 7 to 10 were measured, and a part of the measured data is shown in table 1, and the obtained graph is shown in fig. 9, and it can be seen from fig. 9 that SrZrO obtained by the method of the application example was obtained₃The ceramic block has low infrared emissivity, particularly low infrared emissivity under a window of 3-5 μm, as shown in fig. 9, particularly low emissivity at 500 ℃ of 300-.

TABLE 1 Infrared emissivity measurement numerical table

The embodiments described above are some, but not all embodiments of the invention. The detailed description of the embodiments of the present invention is not intended to limit the scope of the invention as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Claims

_1. a method of preparing SrZrO , is characterized in that, comprises:

The mixture of SrCO ₃ and ZrO ₂ is pressed into a compact for the first time under a pressure of 4-25MPa, and then pressed into a compact for the second time under an isostatic pressing environment, and the pressure of the second compaction is greater than that of the first compaction The pressure is placed in a microwave environment for block treatment. The block treatment is to add powder and bury it, heat it up to 1200-1650°C at a rate of 5-25°C/min and sinter, and keep the temperature for not less than 30min to obtain SrZrO ₃ blocks; or, mix SrCO ₃ and ZrO ₂ and place them in a microwave environment for powder treatment. The powder is treated by heating to 1100-1400° C. and keeping the temperature for not less than 30 minutes to obtain SrZrO ₃ powder. After the SrZrO ₃ powder is compacted, the powder is added for sintering, and the temperature is increased to 1200-1650 ℃ at a rate of 5-25 ℃/min for sintering, and the temperature is kept for not less than 30 minutes to obtain a SrZrO ₃ block.

2. The method of claim 1, wherein the pressure of the second pressing is greater than or equal to 25 MPa.

3. The method of claim 1, wherein the molar ratio of the raw materials of SrCO ₃ and ZrO ₂ is (1-1.1):(0.9-1).

4 . The method of claim 1 , wherein the powder for sintering is selected from at least one of ZrO ₂ and Al ₂ O ₃ .

5. The method of claim 1, wherein the holding time is 30min-6h.

6. A SrZrO ₃ ceramic block, characterized in that, it is prepared by the method of any one of claims 1-5.