CN-118561621-B - High-temperature-resistant foam ceramic wave-absorbing material and preparation method thereof

Abstract

The invention relates to a high-temperature-resistant foam ceramic wave-absorbing material and a preparation method thereof, belonging to the technical field of wave-absorbing stealth materials. The preparation method of the high-temperature-resistant foam ceramic wave-absorbing material comprises the following steps of (1) preparing silicon carbide and calcium carbonate into mixed powder, (2) mixing the mixed powder, borax, sodium silicate, potassium carbonate, polyvinyl alcohol, sodium carboxymethylcellulose and water to prepare slurry, and (3) dipping the foam ceramic member into the slurry, and drying and sintering to obtain the high-temperature-resistant foam ceramic wave-absorbing material. The foam ceramic wave-absorbing material prepared by the invention maintains the original performance of the foam ceramic to the maximum extent, has excellent wave-absorbing performance, and particularly has no influence on the wave-absorbing performance at 850 ℃, which indicates that the foam ceramic wave-absorbing material prepared by the invention has excellent wave-absorbing performance and high temperature resistance.

Inventors

• LI XIANGMING
• YU WANJUN
• MENG QINGHONG
• LV CUICUI

Assignees

• 烟台大学

Dates

Publication Date

20260505

Application Date

20240530

Claims (9)

1. 1. The preparation method of the high-temperature-resistant foam ceramic wave-absorbing material is characterized by comprising the following steps of: (1) Uniformly mixing silicon carbide powder and calcium carbonate powder to prepare mixed powder; (2) Mixing the mixed powder obtained in the step (1), borax, sodium silicate, potassium carbonate, polyvinyl alcohol, sodium carboxymethyl cellulose and water, and uniformly stirring to prepare slurry; (3) Immersing a foamed ceramic member processed by foamed ceramic into the slurry obtained in the step (2), vacuumizing to reduce the surface air pressure of the slurry, and then recovering the surface air pressure of the slurry to normal pressure; (4) Drying the foamed ceramic member obtained in the step (3); (5) And (3) sintering the foamed ceramic member obtained in the step (4), wherein in the sintering process, sintering is carried out for 16-19 min at the temperature of 935-950 ℃ to obtain the high-temperature-resistant foamed ceramic wave-absorbing material.
2. 2. The method for preparing the high-temperature-resistant foamed ceramic wave-absorbing material according to claim 1, wherein in the step (1), the weight ratio of the silicon carbide powder to the calcium carbonate powder is 1 (1.5-2.2).
3. 3. The method for preparing the high-temperature-resistant foamed ceramic wave-absorbing material according to claim 1, wherein in the step (2), the weight ratio of the mixed powder, borax, sodium silicate, potassium carbonate, polyvinyl alcohol, sodium carboxymethyl cellulose and water is (5.3-7.9): (1.2-1.4): (14-16): (1.2-1.5): (0.2-0.3): (0.3-0.5): 100.
4. 4. The method for preparing the high-temperature-resistant foamed ceramic wave-absorbing material according to claim 1, wherein in the step (3), vacuum is pumped to reduce the surface pressure of the slurry to 0.71-0.79 standard atmospheric pressure, and the slurry is kept for 9-13 min.
5. 5. The method for preparing a high temperature resistant foamed ceramic wave absorbing material according to claim 4, wherein in the step (3), the surface air pressure of the slurry is recovered to normal pressure and maintained for 3-5 min.
6. 6. The method for preparing the high-temperature-resistant foamed ceramic wave-absorbing material according to claim 1, wherein in the step (4), heat is preserved for 120-150 min at 85-90 ℃ in the drying process.
7. 7. The method for preparing a high temperature resistant foamed ceramic wave-absorbing material according to claim 1, wherein in the step (1), the average grain diameter of the silicon carbide powder is 10-20 μm.
8. 8. The method for preparing a high temperature resistant foamed ceramic wave absorbing material according to claim 1, wherein in the step (1), the average particle size of the calcium carbonate powder is 5-10 μm.
9. 9. A high temperature resistant foamed ceramic wave absorbing material prepared by the method of any one of claims 1 to 8.

Description

High-temperature-resistant foam ceramic wave-absorbing material and preparation method thereof Technical Field The invention belongs to the technical field of wave-absorbing stealth materials, and particularly relates to a high-temperature-resistant foam ceramic wave-absorbing material and a preparation method thereof. Background The wave-absorbing material is an important structural functional material. With the requirements of higher performance on the wave-absorbing material in the fields of radar stealth, electromagnetic shielding, communication interference prevention, information leakage prevention, military facility radiation prevention and the like, the multi-function is turned into the key development direction of the wave-absorbing material, and particularly for structural wave-absorbing materials, the structural wave-absorbing material is required to have excellent electromagnetic wave-absorbing performance and also is required to meet the requirements of light weight, water resistance, temperature resistance, bearing and the like. The polymer wave-absorbing material has the characteristics of simple molding and convenient use, but has the defects of easy aging, temperature difference resistance, short service life and the like, and cannot meet the multifunctional requirements of the wave-absorbing material. The ceramic wave-absorbing material has excellent temperature resistance, and becomes a research focus of the high-temperature wave-absorbing material, but the problems of complex preparation process and high molding difficulty exist, and the defects of large self weight and poor impact resistance exist in the aspect of performance. Because the foamed ceramic has the advantages of light weight, heat preservation, heat insulation, water resistance, fire resistance and the like, the multifunctional requirement of the structural type wave-absorbing material is just met, and therefore, some students propose to introduce wave-absorbing agents into the foamed ceramic to prepare the high-performance/multifunctional foamed ceramic wave-absorbing material. However, the firing temperature of the ceramic foam is about 1200 ℃, and since the internal pores of the ceramic foam after firing are independent and closed, the wave absorber cannot be introduced into the inside of the ceramic foam, the operation of introducing the wave absorber into the ceramic foam can only be carried out before the ceramic foam sintering process, i.e., the raw material preparation stage, which means that the wave absorber is subjected to high-temperature sintering of 1200 ℃ together with the raw material. The operation has two problems of (1) adding the wave absorber can change the proportion of raw materials, reducing the foaming performance of the foamed ceramic, and needing to comprehensively adjust the proportion of the raw materials and the sintering process, so that the preparation process of the foamed ceramic is more complex, and (2) the wave absorber can be seriously oxidized during high-temperature sintering, so that the prepared foamed ceramic has poor wave absorbing performance. Disclosure of Invention Aiming at the problems of complex process, poor wave absorbing performance and the like of the foamed ceramic wave absorbing material prepared by the prior art, the invention provides a high-temperature-resistant foamed ceramic wave absorbing material and a preparation method thereof. The specific technical scheme is as follows: The first aim of the invention is to provide a preparation method of a high-temperature-resistant foam ceramic wave-absorbing material, which comprises the following steps: (1) Uniformly mixing silicon carbide powder and calcium carbonate powder to prepare mixed powder; (2) Mixing the mixed powder obtained in the step (1), borax, sodium silicate, potassium carbonate, polyvinyl alcohol, sodium carboxymethyl cellulose and water, and uniformly stirring to prepare slurry; (3) Immersing a ceramic foam member processed from commercial ceramic foam in the slurry obtained in the step (2), vacuumizing to reduce the surface pressure of the slurry, and then recovering the surface pressure of the slurry to normal pressure; (4) Taking out the foamed ceramic member obtained in the step (3), placing the foamed ceramic member in an oven, and drying; (5) And (3) taking out the foamed ceramic member obtained in the step (4), placing the foamed ceramic member in a high-temperature furnace, and sintering the foamed ceramic member to obtain the high-temperature-resistant foamed ceramic wave-absorbing material. The technical scheme has the following effects: Silicon carbide in the mixed powder is an excellent high-temperature wave absorber and is dispersed and distributed in open pores on the surface of the foam ceramic member to form a space grid structure, so that the foam ceramic member has excellent electromagnetic wave absorbing performance; During high-temperature sintering, borax, sodium silicate and potassi