阅读说明：本技术 一种低温烧结堇青石/碳化硅复相陶瓷太阳能热发电吸热体材料及其制备方法 (Low-temperature sintered cordierite/silicon carbide composite ceramic solar thermal power generation heat-absorbing body material and preparation method thereof ) 是由 陈健 祝明 黄政仁 马宁宁 陈文辉 于 2021-09-08 设计创作，主要内容包括：本发明涉及一种低温烧结堇青石/碳化硅复相陶瓷太阳能热发电吸热体材料及其制备方法。所述堇青石/碳化硅复相陶瓷太阳能热发电吸热体材料的原料组成包括碳化硅和堇青石；优选,包括：60～90wt%碳化硅,10～40wt%堇青石,各组分含量之和为100wt%。(The invention relates to a low-temperature sintered cordierite/silicon carbide composite ceramic solar thermal power generation heat absorber material and a preparation method thereof. The raw material composition of the cordierite/silicon carbide complex phase ceramic solar thermal power generation heat-absorbing body material comprises silicon carbide and cordierite; preferably, the method comprises the following steps: 60-90 wt% of silicon carbide and 10-40 wt% of cordierite, wherein the sum of the contents of all the components is 100 wt%.)

1. the cordierite/silicon carbide composite ceramic solar thermal power generation heat-absorbing body material is characterized in that the raw material composition of the cordierite/silicon carbide composite ceramic solar thermal power generation heat-absorbing body material comprises silicon carbide and cordierite; preferably, the method comprises the following steps: 60-90 wt% of silicon carbide and 10-40 wt% of cordierite, wherein the sum of the contents of all the components is 100 wt%.

2. The cordierite/silicon carbide composite ceramic solar thermal power generation heat absorber material as claimed in claim 1, wherein the density of the cordierite/silicon carbide composite ceramic solar thermal power generation heat absorber material is 1.8-2.97 g-cm^-3The relative density is 55 to 99.5 percent.

3. The cordierite/silicon carbide composite phase ceramic solar thermal power generation heat-absorbing body material as claimed in claim 1, wherein the cordierite/silicon carbide composite phase ceramic solar thermal power generation heat-absorbing body material has a bending strength of 50-420 MPa and a thermal conductivity of 5-30W (m-K)^-1。

4. The cordierite/silicon carbide composite phase ceramic solar thermal power generation heat absorber material as claimed in claim 1, wherein the cordierite/silicon carbide composite phase ceramic solar thermal power generation heat absorber material has a solar absorptivity of 0.65-0.8, an infrared emissivity of 0.65-0.85 and a spectral selectivity of 0.8-1.2.

5. A method for preparing the cordierite/silicon carbide composite phase ceramic solar thermal power generation heat absorber material according to any one of claims 1 to 4, which comprises the following steps:

(1) mixing silicon carbide powder and cordierite powder to obtain cordierite/silicon carbide composite ceramic powder; (ii) a

(2) And placing the obtained cordierite/silicon carbide complex phase ceramic powder in a graphite mold, prepressing on a dry pressing machine, and then carrying out hot-pressing sintering to obtain the cordierite/silicon carbide complex phase ceramic solar thermal power generation heat-absorbing body material.

6. The method according to claim 5, wherein the silicon carbide powder has a particle size of 0.2 to 2 μm and the cordierite powder has a particle size of 200 to 400 mesh.

7. The preparation method according to claim 5 or 6, characterized in that silicon carbide powder and cordierite powder are mixed, then a solvent is added, and ball milling and mixing are carried out to obtain uniformly mixed slurry; and drying the obtained slurry, and then crushing, sieving and granulating to obtain the cordierite/silicon carbide complex phase ceramic powder.

8. The method according to claim 7, wherein the solvent is water or/and absolute ethanol; the solid content of the slurry is 40-60 wt%, and preferably 50-60 wt%.

9. The preparation method according to claim 7 or 8, wherein the rotation speed of the ball milling and mixing is 200-400 r/min, and the time is 12-48 hours; the drying temperature is 60-90 ℃ and the drying time is 6-24 hours; the number of the sieved meshes is 60-120 meshes.

10. The production method according to any one of claims 7 to 9, wherein the pressure of the pre-pressing is 10 to 25 MPa; the hot-pressing sintering atmosphere is argon or vacuum, the pressure is 10-50MPa, the temperature is 1100-1700 ℃, and the time is 1-3 hours; preferably, the pressure of the hot-pressing sintering is 30-50MPa, and the heating rate of the hot-pressing sintering is 5-20 ℃/min.

Technical Field

The invention relates to a low-temperature sintered cordierite/silicon carbide complex phase ceramic solar thermal power generation heat-absorbing body material and a preparation method thereof, belonging to the field of solar thermal power generation heat-absorbing body materials.

Background

The world energy crisis is increasingly aggravated nowadays, and how to develop and use new energy and realize low carbon emission reduction becomes a problem concerned by all countries in the world. Solar energy is a clean renewable energy source, and is a better choice in solving the energy crisis problem. Therefore, how to utilize solar energy is a subject to which people need to face.

The solar thermal power generation technology can effectively convert solar energy into electric energy for human use. The solar thermal power generation technology can be mainly divided into four systems, namely a tower system, a parabolic trough system, a linear Fresnel system, a parabolic dish system and the like. Among them, the tower-type solar thermal power generation system is valued by various countries and is greatly developed because the system has a high concentration ratio (200-²) High thermodynamic cycle temperature, simple system and the like.

The tower type solar thermal power generation system mainly comprises a heat collection system, a heat transmission and exchange system and a power generation system, and specifically comprises the following components: the device comprises a heliostat, a heat absorber, a tower, a heat accumulator, a heat transmitter and a generator set. The working principle of the tower type solar thermal power generation system is as follows: sunlight is gathered on a heat absorber on the top of the tower through the heliostat, the heat absorber absorbs solar radiation energy, high temperature is generated in a cavity of the heat absorber, heat circulation is achieved through a heat transfer working medium, and heat energy is converted into electric energy.

The heat absorber is a key component in the tower type solar thermal power generation system, and determines the power generation efficiency of the whole thermal power generation system, so that the heat absorber has important significance for the research. The heat absorber material needs to have high solar energy absorption rate, high thermal conductivity, good thermal shock resistance and oxidation resistance. The silicon carbide ceramic can meet the requirements, but the sintering difficulty of the silicon carbide ceramic is extremely high, and the solid phase sintering of the silicon carbide ceramic needs high temperature of more than 2000 ℃, which greatly increases the cost of large-scale application. The problem can be solved by adopting a method of liquid phase sintering of the silicon carbide, because the liquid phase formed at high temperature can play a role in accelerating the mass transfer of the silicon carbide, the purpose of rapidly sintering the silicon carbide ceramic at lower temperature can be realized by adopting the method.

Disclosure of Invention

Based on the problem that silicon carbide ceramic is difficult to sinter, the invention aims to promote the sintering of the silicon carbide ceramic by introducing cordierite materials as liquid-phase sintering aids. The invention aims to provide a low-temperature sintered cordierite/silicon carbide composite ceramic solar thermal power generation heat absorber material and a preparation method thereof.

On one hand, the invention provides a cordierite/silicon carbide complex phase ceramic solar thermal power generation heat-absorbing body material, and the raw material composition of the cordierite/silicon carbide complex phase ceramic solar thermal power generation heat-absorbing body material comprises silicon carbide and cordierite; preferably, the method comprises the following steps: 60-90 wt% of silicon carbide and 10-40 wt% of cordierite, wherein the sum of the contents of all the components is 100 wt%.

According to the invention, the cordierite material has a lower softening temperature, a cordierite liquid phase can be obtained at a lower temperature, and the cordierite liquid phase and silicon carbide have better wettability, so that silicon carbide can be subjected to rapid mass transfer in the cordierite liquid phase, and high-density cordierite/silicon carbide composite ceramic can be obtained at a lower temperature and in a shorter heat preservation time.

Preferably, the density of the cordierite/silicon carbide composite ceramic solar thermal power generation heat absorber material is 1.8-2.97 g-cm^-3The relative density is 55 to 99.5 percent.

Preferably, the cordierite/silicon carbide complex phase ceramic solar thermal power generation heat absorber material has the bending strength of 50-420 MPa and the thermal conductivity of 5-30W (m.K)^-1。

Preferably, the cordierite/silicon carbide composite ceramic solar thermal power generation heat absorber material has a solar energy absorptivity of 0.65-0.8, an infrared emissivity of 0.65-0.85 and a spectral selectivity of 0.8-1.2.

On the other hand, the invention provides a preparation method of a cordierite/silicon carbide complex phase ceramic solar thermal power generation heat absorber material, which comprises the following steps:

(1) mixing silicon carbide powder and cordierite powder to obtain cordierite/silicon carbide composite ceramic powder; (ii) a

(2) And placing the obtained cordierite/silicon carbide complex phase ceramic powder in a graphite mold, prepressing on a dry pressing machine, and then carrying out hot-pressing sintering to obtain the cordierite/silicon carbide complex phase ceramic solar thermal power generation heat-absorbing body material.

Preferably, the particle size of the silicon carbide powder is 0.2-2 μm, and the particle size of the cordierite powder is 200-400 meshes.

Preferably, mixing silicon carbide powder and cordierite powder, adding a solvent, and performing ball milling and mixing to obtain uniformly mixed slurry; and drying the obtained slurry, and then crushing, sieving and granulating to obtain the cordierite/silicon carbide complex phase ceramic powder.

Preferably, the solvent is water or/and absolute ethyl alcohol; the solid content of the slurry is 40-60 wt%, and preferably 50-60 wt%.

Preferably, the rotation speed of the ball milling and mixing is 200-400 r/min, and the time is 12-48 hours.

Preferably, the drying temperature is 60-90 ℃ and the drying time is 6-24 hours.

Preferably, the mesh number of the sieve is 60-120 meshes.

Preferably, the pre-pressing pressure is 10-25 MPa.

Preferably, the hot-pressing sintering atmosphere is argon or vacuum, the pressure is 10-50MPa, the temperature is 1100-1700 ℃, and the time is 1-3 hours; preferably, the pressure of the hot-pressing sintering is 30-50MPa, and the heating rate of the hot-pressing sintering is 5-20 ℃/min.

Has the advantages that:

according to the invention, a hot-pressing sintering method is adopted, silicon carbide and cordierite are compounded, and the cordierite/silicon carbide composite ceramic solar thermal power generation heat-absorbing body material is prepared at a lower temperature. The method solves the problem that the conventional sintering temperature of the silicon carbide is too high (often more than 2000 ℃), the material can be obtained at 1650 ℃, the material has extremely high bending strength which reaches 411.4MPa, and the material has good optical performance and high thermal conductivity and is expected to be applied to a block solar thermal power generation heat absorber.

Drawings

FIG. 1 is a graph of solar absorptance change for each sample;

FIG. 2 is a graph showing the change in IR emissivity of each sample;

FIG. 3 is a graph showing the change in spectral selectivity of each sample.

Detailed Description

The present invention is further illustrated by the following examples, which are to be understood as merely illustrative and not restrictive.

In the disclosure, the low-temperature sintered cordierite/silicon carbide complex phase ceramic solar thermal power generation heat absorption body material comprises silicon carbide and cordierite; preferably comprises 60-90 wt% of silicon carbide and 10-40 wt% of cordierite, and the sum of the contents of all the components is 100 wt%. According to the invention, the silicon carbide is added with cordierite with a specific content to prepare the multiphase ceramic as the heat absorbing material for solar thermal power generation, and the cordierite is added to realize low-temperature sintering by utilizing the lower softening temperature, and because the cordierite is composed of oxide, the use of the cordierite is not limited under an oxidation environment. The silicon carbide particles are compounded with silicon carbide, so that the silicon carbide particles are wrapped in cordierite, and the oxidation resistance of the whole sample is improved. In addition, cordierite also has low density, so that the composite ceramic has the characteristic of light weight as a heat absorbing body material for solar thermal power generation.

The silicon carbide has the advantages of high solar energy absorption rate, high thermal conductivity and the like, but is difficult to sinter, the sintering temperature is often required to be more than 2000 ℃, and a liquid phase sintering method is adopted in the invention, and a cordierite material is selected as a liquid phase sintering auxiliary agent. Because the cordierite material has a lower softening temperature (about 1400 ℃), a cordierite liquid phase can be obtained at a lower temperature, and the cordierite liquid phase and silicon carbide have better wettability, so that silicon carbide can be rapidly transferred in the cordierite liquid phase, and high-density cordierite/silicon carbide composite ceramic can be obtained at a lower temperature and in a shorter holding time.

According to the invention, a hot-pressing sintering method is adopted, silicon carbide and cordierite are compounded, and the cordierite/silicon carbide composite ceramic solar thermal power generation heat-absorbing body material is prepared at a lower temperature.

The preparation method of the low-temperature sintered cordierite/silicon carbide composite phase ceramic solar thermal power generation heat absorber material is exemplarily described below.

Weighing a proper amount of silicon carbide powder and cordierite powder, adding a proper amount of solvent and silicon carbide ball grinding balls with certain mass into the mixed powder, placing the mixture on a planetary ball mill, and carrying out ball milling and mixing for 12-48 hours, preferably 24-48 hours, so as to obtain uniform mixed slurry. The content of the silicon carbide powder can be 60-90 wt%, and the content of the cordierite powder can be 10-40 wt%. The grain diameter of the silicon carbide powder can be 0.2-2 mu m, and the grain diameter of the cordierite powder can be 200-400 meshes. The proper amount of solvent is water or absolute ethyl alcohol. The solid content of the uniformly mixed slurry may be 40 to 60wt%, and preferably may be 50 to 60 wt%.

Placing the uniformly mixed slurry in an oven, and drying at 60-100 ℃, preferably 70-90 ℃; and crushing and sieving the dried slurry to obtain the cordierite/silicon carbide complex phase ceramic powder. The drying time may be 6 to 24 hours, and may preferably be 12 to 24 hours. The number of the screening meshes can be 60-120 meshes.

Weighing a proper amount of cordierite/silicon carbide powder, placing the cordierite/silicon carbide powder in a graphite crucible, and pre-pressing the cordierite/silicon carbide powder on a dry pressing machine, wherein the pre-pressing pressure can be 10-25 MPa; and then placing the graphite crucible filled with the powder in a hot pressing furnace, applying a certain pressure, and sintering at a lower temperature to obtain the cordierite/silicon carbide complex phase ceramic solar thermal power generation heat-absorbing body material. The pressure of the hot-pressing sintering can be 10-50MPa, and preferably 30-50 MPa. The hot-pressing sintering temperature can be 1100-1700 ℃, the heat preservation time is 1-3 hours, and the heating rate in the sintering process can be 5-20 ℃/min. The hot-pressing sintering atmosphere can be argon or vacuum.

In the invention, the density of the low-temperature sintered cordierite/silicon carbide composite ceramic solar thermal power generation heat absorber material measured by an Archimedes drainage method can be 1.8-2.97 g-cm^-3。

In the invention, the relative density of the low-temperature sintered cordierite/silicon carbide composite ceramic solar thermal power generation heat absorber material can be 55-99.5%.

In the invention, the bending strength of the low-temperature sintered cordierite/silicon carbide complex phase ceramic solar thermal power generation heat absorber material is measured to be 50-420 MPa by adopting a three-point bending resistance method.

According to the invention, the solar energy absorptivity and the infrared emissivity of the low-temperature sintering cordierite/silicon carbide complex phase ceramic solar thermal power generation heat absorber material respectively measured by an ultraviolet spectrophotometer and a Fourier infrared spectrometer are respectively 0.65-0.8 and 0.65-0.85, and the spectral selectivity is calculated to be 0.8-1.2.

In the invention, the thermal conductivity of the low-temperature sintered cordierite/silicon carbide complex phase ceramic solar thermal power generation heat absorber material measured by a laser thermal conductivity meter is 5-30W (m.K)^-1。

The present invention will be described in detail by way of examples. It is also to be understood that the following examples are illustrative of the present invention and are not to be construed as limiting the scope of the invention, and that certain insubstantial modifications and adaptations of the invention by those skilled in the art may be made in light of the above teachings. The specific process parameters and the like of the following examples are also only one example of suitable ranges, i.e., those skilled in the art can select the appropriate ranges through the description herein, and are not limited to the specific values exemplified below.

Example 1

Weighing 70g of silicon carbide powder and 30g of cordierite powder, adding a certain amount of absolute ethyl alcohol as a solvent, adding 100g of silicon carbide ball milling balls, and ball milling for 24 hours by using a planetary ball mill to reduce the particle size of the powder and uniformly mix the powder to obtain uniformly mixed slurry with the solid content of preferably 50-60 wt%. Drying the uniformly mixed slurry in an oven at 70 ℃ for 12 hours; and crushing the dried slurry, and sieving the crushed dried slurry by a 100-mesh sieve to obtain the granulated cordierite/silicon carbide complex phase ceramic powder. Weighing a proper amount of the granulation-finished powder, placing the granulation-finished powder in a graphite crucible, and prepressing on a dry pressing machine, wherein the prepressing pressure is 15 MPa; then placing the graphite crucible filled with the powder in a hot pressing furnace, applying 40MPa pressure, sintering at 1450 ℃, wherein the heating rate is 10 ℃/min, the heat preservation time is 2 hours, and the sintering atmosphere is argon atmosphere, thus obtaining the graphite crucibleTo cordierite/silicon carbide complex phase ceramic solar thermal power generation heat-absorbing body material. The density of the cordierite/silicon carbide complex phase ceramic solar thermal power generation heat-absorbing body material is 2.56g/cm^-3The relative density is 85.45 percent, the bending strength is 219.52MPa, the solar energy absorptivity is 0.781, the infrared emissivity is 0.724, the spectral selectivity is 1.08, and the thermal conductivity is 11.553W (m.K)^-1。

Example 2

Weighing 70g of silicon carbide powder and 30g of cordierite powder, adding a certain amount of absolute ethyl alcohol as a solvent, adding 100g of silicon carbide ball milling balls, and ball milling for 24 hours by using a planetary ball mill to reduce the particle size of the powder and uniformly mix the powder to obtain uniformly mixed slurry with the solid content of preferably 50-60 wt%. Drying the uniformly mixed slurry in an oven at 70 ℃ for 12 hours; and crushing the dried slurry, and sieving the crushed dried slurry by a 100-mesh sieve to obtain the granulated cordierite/silicon carbide complex phase ceramic powder. Weighing a proper amount of the granulation-finished powder, placing the granulation-finished powder in a graphite crucible, and prepressing on a dry pressing machine, wherein the prepressing pressure is 15 MPa; and then placing the graphite crucible filled with the powder in a hot pressing furnace, applying 40MPa pressure, sintering at 1550 ℃, wherein the heating rate is 10 ℃/min, the heat preservation time is 2 hours, and the sintering atmosphere is argon atmosphere, so as to obtain the cordierite/silicon carbide complex phase ceramic solar thermal power generation heat-absorbing body material. The cordierite/silicon carbide composite ceramic solar thermal power generation heat-absorbing body material has the density of 2.79g/cm & lt-3 & gt, the relative density of 93.13%, the bending strength of 260.54MPa, the solar energy absorptivity of 0.778, the infrared emissivity of 0.691 and the spectral selectivity of 1.13.

Example 3

Weighing 70g of silicon carbide powder and 30g of cordierite powder, adding a certain amount of absolute ethyl alcohol as a solvent, adding 100g of silicon carbide ball milling balls, and ball milling for 24 hours by using a planetary ball mill to reduce the particle size of the powder and uniformly mix the powder to obtain uniformly mixed slurry with the solid content of preferably 50-60 wt%. Drying the uniformly mixed slurry in an oven at 70 ℃ for 12 hours; and crushing the dried slurry, and sieving the crushed dried slurry by a 100-mesh sieve to obtain the granulated cordierite/silicon carbide complex phase ceramic powder.Weighing a proper amount of the granulation-finished powder, placing the granulation-finished powder in a graphite crucible, and prepressing on a dry pressing machine, wherein the prepressing pressure is 15 MPa; and then placing the graphite crucible filled with the powder in a hot pressing furnace, applying 40MPa pressure, sintering at 1650 ℃, wherein the heating rate is 10 ℃/min, the heat preservation time is 2 hours, and the sintering atmosphere is argon atmosphere, so as to obtain the cordierite/silicon carbide complex phase ceramic solar thermal power generation heat-absorbing body material. The cordierite/silicon carbide complex phase ceramic solar thermal power generation heat-absorbing body material has the density of 2.97g/cm & lt-3 & gt, the relative density of 99.08%, the bending strength of 411.44MPa, the solar energy absorption rate of 0.778, the infrared emissivity of 0.677, the spectral selectivity of 1.15 and the thermal conductivity of 25.049W (m.K)^-1。

Example 4

Weighing 70g of silicon carbide powder and 30g of cordierite powder, adding a certain amount of absolute ethyl alcohol as a solvent, adding 100g of silicon carbide ball milling balls, and ball milling for 24 hours by using a planetary ball mill to reduce the particle size of the powder and uniformly mix the powder to obtain uniformly mixed slurry with the solid content of preferably 50-60 wt%. Drying the uniformly mixed slurry in an oven at 70 ℃ for 12 hours; and crushing the dried slurry, and sieving the crushed dried slurry by a 100-mesh sieve to obtain the granulated cordierite/silicon carbide complex phase ceramic powder. Weighing a proper amount of the granulation-finished powder, placing the granulation-finished powder in a graphite crucible, and prepressing on a dry pressing machine, wherein the prepressing pressure is 15 MPa; and then placing the graphite crucible filled with the powder in a hot pressing furnace, applying 40MPa pressure, sintering at 1350 ℃, wherein the heating rate is 10 ℃/min, the heat preservation time is 2 hours, and the sintering atmosphere is argon atmosphere, so as to obtain the cordierite/silicon carbide complex phase ceramic solar thermal power generation heat-absorbing body material. The density of the cordierite/silicon carbide complex phase ceramic solar thermal power generation heat-absorbing body material is 2.3g/cm^-3The relative density is 76.97%, the bending strength is 181.51MPa, the solar energy absorptivity is 0.729, the infrared emissivity is 0.778, the spectral selectivity is 0.94, and the thermal conductivity is 8.341W (m.K)^-1。

Example 5

Weighing 80g of silicon carbide powder and 20g of cordierite powder, adding a certain amount of absolute ethyl alcohol as a solvent, and then adding 100g of silicon carbideAnd ball milling the balls for 24 hours by using a planetary ball mill, so that the particle size of the powder is reduced and the powder is uniformly mixed to obtain uniformly mixed slurry with the solid content of 50-60 wt% preferably. Drying the uniformly mixed slurry in an oven at 70 ℃ for 12 hours; and crushing the dried slurry, and sieving the crushed dried slurry by a 100-mesh sieve to obtain the granulated cordierite/silicon carbide complex phase ceramic powder. Weighing a proper amount of the granulation-finished powder, placing the granulation-finished powder in a graphite crucible, and prepressing on a dry pressing machine, wherein the prepressing pressure is 15 MPa; and then placing the graphite crucible filled with the powder in a hot pressing furnace, applying 40MPa pressure, sintering at 1350 ℃, wherein the heating rate is 10 ℃/min, the heat preservation time is 2 hours, and the sintering atmosphere is argon atmosphere, so as to obtain the cordierite/silicon carbide complex phase ceramic solar thermal power generation heat-absorbing body material. The density of the cordierite/silicon carbide complex phase ceramic solar thermal power generation heat-absorbing body material is 2.05g/cm^-3The relative density is 67.03%, the bending strength is 113.48MPa, the solar absorptivity is 0.725, the infrared emissivity is 0.794, and the spectral selectivity is 0.91.

Example 6

Weighing 90g of silicon carbide powder and 10g of cordierite powder, adding a certain amount of absolute ethyl alcohol as a solvent, adding 100g of silicon carbide ball milling balls, and ball milling for 24 hours by using a planetary ball mill to reduce the particle size of the powder and uniformly mix the powder to obtain uniformly mixed slurry with the solid content of preferably 50-60 wt%. Drying the uniformly mixed slurry in an oven at 70 ℃ for 12 hours; and crushing the dried slurry, and sieving the crushed dried slurry by a 100-mesh sieve to obtain the granulated cordierite/silicon carbide complex phase ceramic powder. Weighing a proper amount of the granulation-finished powder, placing the granulation-finished powder in a graphite crucible, and prepressing on a dry pressing machine, wherein the prepressing pressure is 15 MPa; and then placing the graphite crucible filled with the powder in a hot pressing furnace, applying 40MPa pressure, sintering at 1300 ℃, wherein the heating rate is 10 ℃/min, the heat preservation time is 2 hours, and the sintering atmosphere is argon atmosphere, so as to obtain the cordierite/silicon carbide complex phase ceramic solar thermal power generation heat-absorbing body material. The density of the cordierite/silicon carbide complex phase ceramic solar thermal power generation heat-absorbing body material is 1.84g/cm^-3The relative density is 58.88 percent, and the bending strength is 6345MPa, solar absorptivity of 0.682, infrared emissivity of 0.818 and spectral selectivity of 0.83.

Table 1 shows the performance parameters of the cordierite/silicon carbide composite ceramic solar thermal power generation heat absorber material prepared by the present invention: