阅读说明：本技术 一种具有可调控负介电常数的氧化铝陶瓷浸渍蔗糖材料及其制备方法 (Alumina ceramic impregnated sucrose material with adjustable negative dielectric constant and preparation method thereof ) 是由 程传兵 孙晓 沈建兴 于 2019-11-18 设计创作，主要内容包括：本专利涉及一种可调控介电常数氧化铝陶瓷浸渍蔗糖的制备方法,该材料的组成主要包括基体相的氧化铝陶瓷和导电相的蔗糖裂解碳,通过调节不同的浸渍次数来调整体系中导电相的含量。该材料的成分组成可用化学式xC/(1-x)Al<Sub>2</Sub>O<Sub>3</Sub>表示,所制备方法包括以下步骤：(1)多孔氧化铝陶瓷的制备(配料、球磨、成型、烧结)；(2)浸渍蔗糖；(3)还原得到相应的碳含量。本发明通过在氧化铝陶瓷基体中浸渍蔗糖还原裂解碳作为导电相,从而能得到既具有陶瓷材料高强度硬度的优异性能,又具有导电性,在一定外加磁场的范围内实现负介电常数。(The invention relates to a preparation method of alumina ceramic impregnated sucrose with adjustable dielectric constant, which mainly comprises alumina ceramic of a matrix phase and sucrose cracking carbon of a conductive phase, and the content of the conductive phase in a system is adjusted by adjusting different impregnation times. The composition of the material can be represented by the chemical formula xC/(1-x) Al 2 O 3 The preparation method comprises the following steps: (1) preparing porous alumina ceramics (burdening, ball-milling, molding and sintering); (2) dipping sucrose; (3) reducing to obtain the corresponding carbon content. The invention relates to aThe alumina ceramic matrix is impregnated with sucrose reduction cracking carbon as a conductive phase, so that the ceramic material has the excellent performance of high strength and hardness and conductivity, and the negative dielectric constant is realized in a certain range of an external magnetic field.)

1. Al (aluminum)₂O₃A process for preparing cane sugar impregnated ceramic material with xC/(1-x) Al₂O₃It is shown that the main raw material for preparation comprises Al₂O₃Carbon powder, TiO₂And sucrose. The preparation method is characterized by comprising the following steps:

(1) 18 weight percent of active carbon and 3 weight percent of TiO according to the mass ratio₂(sintering aid) and corresponding amount of Al₂O₃Weighing, and placing the mixture in a ball milling tank for ball milling for 6 hours at 200r/min by taking absolute ethyl alcohol as a dispersion medium. Drying to obtain uniformly mixed powder, adding a proper amount of PVA as a binder to grind the prepared powder, granulating, drying, sieving and molding into ceramic plates with phi =19mm and t =2mm, and placing the obtained green bodies in a muffle furnace for sintering.

(2) Preparing sucrose growth solution with a certain concentration, and dividing the ceramic wafer in the step (1) into four components to obtain C/Al with the same components₂O₃Cracking the carbon ceramic sample. (3) Reduction treatment, namely placing samples with different components in a vacuum tube furnace at 600 ℃ respectively^oC、750^oC、900^oC、1050^oAnd C, reducing for 2 h.

2. The C/Al of claim 1₂O₃The preparation method of the ceramic is characterized by comprising the following steps: the preparation method comprises ball milling and drying; in the step (1), the ceramic wafer is sintered for 6 hours in a muffle furnace at 600 ℃, and the sintering temperature curve is as follows:

room temperature^120min—600^oC—^360min—600^oC—^120min-room temperature

And (3) sintering the ceramic wafer in a vacuum tube furnace at 600 ℃ for 2 hours, wherein the sintering temperature curve under the protective atmosphere of nitrogen is as follows:

room temperature^120min—600^oC—^120min—600^oC—^120min-room temperature.

Technical Field

The invention relates to the technical field of negative parameters, in particular to sucrose serving as a cracking carbon material source.

Background

Most of electromagnetic parameters of traditional materials are positive values, and only a few materials in nature have negative parameters, but with the continuous exploration and research of people on the material category, the fact that a material with a controllable negative dielectric constant can be obtained by regulating and controlling the microstructure and the proportion of the material is found, and the material with the negative parameters is called as a metamaterial.

Most of electromagnetic parameters of traditional materials are positive values, and only a few materials in nature have negative parameters, but with the continuous exploration and research of people on the material category, the fact that a material with a controllable negative dielectric constant can be obtained by regulating and controlling the microstructure and the proportion of the material is found, and the material with the negative parameters is called as a metamaterial.

Disclosure of Invention

In order to solve the problem that the negative dielectric constant of the existing metal metamaterial is not easy to adjust, sucrose is selected as a functional material, when a carbon material cracks an amorphous carbon film at a certain temperature, the amorphous carbon film can be uniformly attached to the surface of ceramic particles, and the metamaterial with the negative dielectric constant easy to adjust is prepared.

In order to achieve the technical purpose, the technical scheme of the invention is as follows:

the invention designs a C/Al₂O₃The preparation method of the metamaterial comprises the following steps of: xC/Al₂O₃The main preparation raw materials comprise activated carbon, alumina powder, titanium dioxide and sucrose. The preparation method is characterized by comprising the following steps:

(1) 18 weight percent of active carbon and 3 weight percent of TiO according to the mass ratio₂(sintering aid) and corresponding amount of Al₂O₃Weighing, and placing the mixture in a ball milling tank for ball milling for 6 hours at 200r/min by taking absolute ethyl alcohol as a dispersion medium. Drying to obtain uniformly mixed powder, adding a proper amount of PVA as a binder to grind the prepared powder, granulating, drying, sieving and molding into ceramic plates with phi =19mm and t =2mm, and placing the obtained green bodies in a muffle furnace for sintering.

(2) Preparing sucrose growth solution with a certain concentration, and dividing the ceramic wafer in the step (1) into four components to obtain C/Al with the same components₂O₃Cracking the carbon ceramic sample.

(3) Reduction treatment, namely placing samples with different components in a vacuum tube furnace at 600 ℃ respectively^oC、750^oC、900^oC、1050^oAnd C, reducing for 2 h.

2. The C/Al of claim 1₂O₃The preparation method of the ceramic is characterized by comprising the following steps: the preparation method comprises ball milling and drying; in the step (1), the ceramic wafer is sintered for 6 hours in a muffle furnace at 600 ℃, and the sintering temperature curve is as follows:

room temperature^120min—600^oC—^360min—600^oC—^120min-room temperature

The ceramic sheet is processed at 600 in the step (3)^oC、750^oC、900^oC、1050^oAnd C, sintering for 2 hours in a vacuum tube furnace under the protective atmosphere of nitrogen, wherein the sintering temperature curve is as follows:

room temperature^120min—600^oC—^120min—600^oC—^120min-room temperature

Room temperature^150min—750^oC—^120min—750^oC—^150min-room temperature

Room temperature^180min—900^oC—^120min—900^oC—^180min-room temperature

Room temperature^210min—1050^oC—^120min—1050^oC—^210min-room temperature

Researches show that the sintering temperature of the composite material has great influence on the dielectric property of the composite material.

The invention has the beneficial effects that:

(1) the adjustable negative parameters can be realized by changing the sintering temperature through the metamaterial provided by the invention.

(2) The metamaterial prepared by the method is expected to be used in the fields of stealth, radar and the like.

Drawings

The invention will be further elucidated with reference to the drawings and the detailed description:

FIG. 1 different temperatures C/Al₂O₃XRD schematic of composite materials

FIG. 2750^oC/Al under C₂O₃Raman spectrum of composite material

FIG. 3 Mo/Al at different temperatures₂O₃Schematic diagram of dielectric constant of the composite material.

Detailed Description

A preparation method of a metamaterial comprises the following steps: