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High-temperature-resistant high-entropy wave-absorbing ceramic as well as preparation method and application thereof

A high-temperature, high-entropy technology, applied in chemical instruments and methods, boron/borides, metal borides, etc., can solve the problem of large size adjustability of lattice accommodated metal atoms, low density and high temperature stability, loss of wave absorption capacity and other issues, to achieve the effect of being suitable for large-scale production and application, good high temperature stability, and improving absorbing performance

Active Publication Date: 2021-02-26
AEROSPACE RES INST OF MATERIAL & PROCESSING TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, when applied at high temperature, both materials have their own inherent defects: the absorbing material based on carbon material will lose its absorbing ability due to the oxidation of carbon material at high temperature, while the ferrite magnetic nanomaterial At high temperature, the absorption performance will be rapidly attenuated due to the weakening of magnetism and the growth of nanomaterial grains.
[0004] The rare earth hexaboride not only has the characteristics of low density and good high temperature stability, but also has a large adjustable size of metal atoms in its crystal lattice, and has a good performance control space, which is conducive to a wide range of its performance by adding different metals. control, but there is no research and report on its electromagnetic absorption performance

Method used

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  • High-temperature-resistant high-entropy wave-absorbing ceramic as well as preparation method and application thereof
  • High-temperature-resistant high-entropy wave-absorbing ceramic as well as preparation method and application thereof
  • High-temperature-resistant high-entropy wave-absorbing ceramic as well as preparation method and application thereof

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Experimental program
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preparation example Construction

[0043] The preparation method of the high-temperature-resistant high-entropy wave-absorbing ceramics of the present invention comprises the following steps:

[0044] (1) raw material powder is mixed with absolute ethanol in a ball mill tank to obtain a uniformly mixed slurry;

[0045] (2) The obtained slurry is dried and sieved to obtain a mixed powder, and the powder is put into a high-temperature electric furnace for calcination to obtain a ceramic powder;

[0046] In step (2), the calcination temperature is 1900°C-2000°C, the calcination time is 1-2h, and the calcination vacuum degree is controlled at 8-15Pa. The sintering temperature and time mainly affect the purity of ceramic materials. If the sintering temperature is too low and lower than the minimum value of the above range, the raw material powder cannot fully react to obtain pure high-entropy hexaboron ceramics. If the sintering temperature is too short and shorter than the minimum value of the above range When the...

Embodiment 1

[0049] Will Y 2 o 3 、Sm 2 o 3 、Eu 2 O3, Yb 2 o 3 、Er 2 o 3 and B 4 C Press Y 2 o 3 :Sm 2 o 3 :Eu 2 o 3 :Yb 2 o 3 :Er 2 o 3 :B 4The molar ratio of C=1:1:1:1:1:15 is weighed, mixed in the ball mill tank, the mixing time is 6 hours, the mixing medium is dehydrated alcohol, obtains the slurry; the slurry obtained is filtered and Carry out drying treatment and pass through a 120-mesh sieve to obtain a mixture powder, put the dried powder into a high-temperature furnace for calcination, the calcination temperature is 1900°C, the calcination time is 2 hours, and the vacuum degree is 8Pa to obtain high-entropy hexaboride ceramics (Y 1 / 5 SM 1 / 5 Eu 1 / 5 Yb 1 / 5 Er 1 / 5 )B 6 Powder, the ceramic purity is 100wt%, the average particle size is 1.86 microns, the maximum absorption loss is 33.4dB at the frequency of 2-18GHz, and the maximum absorption frequency bandwidth is when the reflectivity is below -10dB when tested by Agilent N5244A vector network analyzer 3.9GHz...

Embodiment 2

[0051] Will Y 2 o 3 、Sm 2 o 3 、Eu 2 O3, Yb 2 o 3 、Er 2 o 3 and B 4 C Press Y 2 o 3 :Sm 2 o 3 :Eu 2 o 3 :Yb 2 o 3 :Er 2 o 3 :B 4 The molar ratio of C=1:1:1:1:1:15 is weighed, mixed in a ball mill tank, the mixing time is 6 hours, and the mixing medium is anhydrous ethyl alcohol to obtain a slurry; the obtained slurry Filter and dry and pass through a 120-mesh sieve to obtain the mixture powder. Put the dried powder into a high-temperature furnace for calcination. The calcination temperature is 2000°C, the calcination time is 1 hour, and the vacuum degree is 15Pa to obtain high-entropy hexaboron Compound ceramics (Y 1 / 5 SM 1 / 5 Eu 1 / 5 Yb 1 / 5 Er 1 / 5 )B 6 Powder, the purity of ceramics is 100wt%, the average particle size is 2.1 microns, the maximum absorption loss is 30dB at the frequency of 2-18GHz when the Agilent N5244A vector network analyzer is used, and the maximum absorption frequency bandwidth is 3.6GHz.

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Abstract

The invention relates to high-temperature-resistant high-entropy wave-absorbing ceramic as well as a preparation method and application thereof. The high-entropy ceramic is prepared from the followingraw materials in parts by mole: 0.98-1.02 parts of cerium oxide, 0.98-1.02 parts of yttrium oxide, 0.98-1.02 parts of samarium oxide, 0.98-1.02 parts of erbium oxide, 0.98-1.02 parts of ytterbium oxide and 15 parts of boron carbide. The high-entropy ceramic has the advantages of low density, high purity, strong wave absorption performance and wide absorption frequency band, the maximum wave absorption loss is 28-34dB, and the maximum absorption frequency band width is 3.5-3.9 GHz. The high-temperature-resistant high-entropy wave-absorbing ceramic is obtained through a high-temperature electric furnace under the vacuum condition by utilizing a high-entropy technology and introducing not less than 5 rare earth metal elements into hexaboride at the same time, and due to the influence of thehigh-entropy effect, the high-temperature stability of a reaction product is better, so that the required reaction conditions are lower, the process is simple and rapid, the practicability is high, and the ceramic is suitable for industrial production and has a good application prospect in the field of wave-absorbing materials.

Description

technical field [0001] The invention belongs to the field of microwave absorbing materials and their preparation and application, and relates to a high-temperature-resistant high-entropy microwave-absorbing ceramic and its preparation method and application, in particular to a high Entropic ceramics and their preparation methods and applications. Background technique [0002] With the development of modern science and technology, various electronic and electrical equipment have provided great help to people's daily life, but at the same time, the electromagnetic radiation and interference problems generated by these equipment have created new problems for people's production and life , deteriorating human existence in space. In addition, in the military field, due to the need for radar stealth, aircraft need to avoid the effect of electromagnetic waves. Therefore, it is necessary to develop absorbing materials to absorb electromagnetic wave signals. Ideal absorbing materi...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01B35/04C01B35/00
CPCC01B35/04C01B35/00C01P2006/80C01P2004/61C01P2006/40C01P2006/42
Inventor 向会敏张伟明周延春戴付志
Owner AEROSPACE RES INST OF MATERIAL & PROCESSING TECH
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