Method for preparing boron carbide ceramic material through low-temperature fast sintering

A rapid sintering technology for boron carbide ceramics, applied in the field of ceramic materials, can solve the problems of uneven microstructure of ceramics, easy agglomeration of ultra-fine powder, and influence of ceramic performance, and achieve good application prospects, good sintering activity, and fast heating speed Effect

Inactive Publication Date: 2015-03-11
DONGHUA UNIV +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, ultra-fine powders are easy to agglomerate, resulting in uneven microstructure of ceramics, and the grains tend to grow abnormally during the sintering process, which will have a great impact on the performance of ceramics.

Method used

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  • Method for preparing boron carbide ceramic material through low-temperature fast sintering
  • Method for preparing boron carbide ceramic material through low-temperature fast sintering
  • Method for preparing boron carbide ceramic material through low-temperature fast sintering

Examples

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Effect test

Embodiment 1

[0019] A method for preparing a boron carbide ceramic material by rapid sintering at low temperature, the specific steps are:

[0020] (1) Using the hard template mesoporous silica SBA-15 as the structure-directing agent, the porous boron carbide powder was synthesized by nano-casting method: 2.73g of mesoporous silica SBA-15 and 2.5g of the precursor didecaboryl - Disperse bisdecaboranyl-hexane (bisdecaboranyl-hexane) in 200ml of absolute ethanol and stir evenly, and the solvent is rotated to evaporate the solvent. Put the body into an alumina crucible, heat-treat it under an argon atmosphere, raise the temperature to 300°C at a heating rate of 1°C / min, keep it for 7 hours, then raise it to 700°C at a rate of 0.5°C / min, keep it for 1 hour, and then heat it at 2°C / min The temperature was raised to 1000°C for 2 hours, and the precursor was converted into boron carbide (B 4 C), soak the heat-treated powder with an ethanol solution containing 40% hydrofluoric acid, repeat severa...

Embodiment 2

[0024] A method for preparing a boron carbide ceramic material by rapid sintering at low temperature, the specific steps are:

[0025] (1) Using the hard template mesoporous silica KIT-6 as the structure-directing agent, the porous boron carbide powder was synthesized by nano-casting method: 1.95g of mesoporous silica KIT-6 and 2.5g of the precursor didecaboryl - Disperse bisdecaboranyl-hexane (bisdecaboranyl-hexane) into 200ml of absolute ethanol and stir evenly, and volatilize the solvent in a Petri dish covered with PE film to introduce the precursor bisdecaboranyl-hexane (bisdecaboranyl-hexane) into the hard disk In the channel of the template, put the obtained powder into an alumina crucible, heat treatment in an argon atmosphere, raise the temperature to 300°C at a heating rate of 1°C / min, keep it for 7 hours, and then raise the temperature to 700°C at a rate of 0.5°C / min , keep it warm for 1h, then raise the temperature at 2°C / min to 1000°C for 2h, and convert the precu...

Embodiment 3

[0029] A method for preparing a boron carbide ceramic material by rapid sintering at low temperature, the specific steps are:

[0030] (1) Using the hard template mesoporous silica MCM-41 as the structure-directing agent, the porous boron carbide powder was synthesized by nano-casting method: 2.3g of mesoporous silica MCM-41 and 2.5g of the precursor didecaboryl - Disperse bisdecaboranyl-hexane (bisdecaboranyl-hexane) in 200ml of absolute ethanol and stir evenly, and the solvent is rotated to evaporate the solvent. Put the body into an alumina crucible, heat treatment under nitrogen atmosphere, raise the temperature to 300°C at a heating rate of 1°C / min, keep it for 7h, then raise the temperature to 700°C at 0.5°C / min, keep it for 1h, and then heat it at 0.5°C / min Raise the temperature to 1000°C and keep it for 1h to convert the precursor into boron carbide (B 4 C), soak the heat-treated powder with an ethanol solution containing 40% hydrofluoric acid, repeat several times to...

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Abstract

The invention provides a method for preparing a boron carbide ceramic material through low-temperature fast sintering. The method is characterized in comprising the following steps: a hard template is adopted as a structure-directing agent; porous boron carbide powder is synthesized with a nano-scale casting method; the porous boron carbide powder is added into a graphite mold, and the mold is placed into a chamber of a spark plasma sintering furnace; sintering is carried out under vacuum and in an inert or reductive atmosphere; after sintering, the product is cooled to room temperature with the furnace; and grinding is carried out, such that the boron carbide ceramic material is obtained. According to the low-temperature fast sintering boron carbide ceramic preparation method, the porous boron carbide powder is adopted as a sintering raw material. The porous boron carbide powder has the advantages of large specific surface area, high surface energy, good sintering activity, and the like, such that the powder is easier to be densified during sintering. Also, pressurization can be realized during a sintering process with a spark plasma sintering technology, such that pore collapse and densification of the porous boron carbide powder can be facilitated, and thus the boron carbide ceramic can be obtained under a relatively low temperature. The technology has advantages of fast temperature increasing speed, short sintering time, and the like. The method is an energy-saving and environment-friendly preparation method, and has good application prospect.

Description

technical field [0001] The invention belongs to the technical field of ceramic materials, in particular to a method for preparing boron carbide ceramic materials by low-temperature rapid sintering. Background technique [0002] Boron carbide is one of the important special ceramic materials with high hardness and high modulus. It has good thermal stability under inert atmosphere, strong oxidation resistance, low density (2.52g / cm 3 ), good wear resistance and other excellent properties, it can be used in air nozzles, lightweight armor plates, wear-resistant materials and other fields. Due to the strong neutron absorption efficiency of boron atoms, it is also a popular research object for neutron absorbing or shielding materials in the nuclear industry. But boron carbide (chemical formula is B 4 C) In the crystal structure, about more than 93% of boron and carbon are combined in the form of strong covalent bonds, the self-diffusion coefficient is low, and the grain boundar...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C04B35/563C04B35/622
Inventor 王连军张欣顾士甲江莞赵涛许虹杰李华坚
Owner DONGHUA UNIV
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