Jet 3D printing functional gradient electromagnetic protective material and preparation method thereof

Abstract

The invention relates to a jet 3D printing functional gradient electromagnetic protective material and a preparation method thereof. The material comprises an impedance gradient absorbing layer and amatching layer, the matching layer is close to the air, the impedance of the matching layer is close to that of a free space, the matching layer and the absorbing layer jointly form a wave absorbing layer, and a substrate of the wave absorbing layer is magnesium phosphate cement; and during jet 3D printing, in raw materials of the magnesium phosphate cement, potassium dihydrogen phosphate, borax,metakaolin and nano wave-absorbing particle ferroferric oxide form a group, magnesium oxide forms a group, an aqueous solution forms a group, porous ceramsite forms a group, the four groups of raw materials are placed in four stock bins correspondingly, a flow speed of the materials in each stock bin entering printing equipment is controlled, the mixing amount of all groups of the materials entering a stirring bin part of the printing equipment is changed, the impedance values of different printing layers are regulated and controlled, and the impedance values are set from near to far accordingto a distance approaching to a concrete substrate in the wave absorbing layer and gradually increased in an arithmetic progression mode. The material provided by the invention has god structural bonding performance, obviously-improved electromagnetic protection effects and durability, and low costs.

Description

technical field [0001] The invention belongs to the technical field of new building materials, and specifically relates to a high-absorption, wide-band, high-stability and digitally intelligently controllable spray 3D printing functional gradient electromagnetic protection magnesium phosphate cement (MPC-EA)-based composite material and a preparation method thereof. Background technique [0002] Electromagnetic waves are widely used in fields such as radio communications, medical equipment, household appliances, and military installations. At the same time, the widespread use of electromagnetic waves has brought extensive electromagnetic radiation hazards, causing serious electromagnetic radiation pollution, and posing a serious threat to precision electronic equipment, health and military defense. The surface coating of cement-based electromagnetic absorbing materials is one of the effective means of electromagnetic radiation protection for existing building structures, and...

AI Technical Summary

Problems solved by technology

[0003] 1) Poor structural functionality: Although the wave-absorbing material can be added to traditional concrete to improve the wave-absorbing performance of concrete, usually the mechanical and structural properties of the material have been significantly reduced when the threshold dosage that meets the wave-absorbing performance requirements has not been reached.

In addition, traditional Portland cement has poor bonding performance, and the changes in ambient temperature and humidity and different use methods cause problems such as low service life, easy to fall off, and easy to crack, which seriously reduces the reliability and electromagnetic protection performance of buildings.

[0004] 2) The effect of electromagnetic protection is poor: the material’s electromagnetic wave absorption efficiency is closely related to the frequency of electromagnetic waves, the type of absorbing agent and its dispersion, and the thickness of absorbing materials.

The thickness and material uniformity of the electromagnetic protection layer cannot be accurately guaranteed when applying cement in the traditional construction process, which may easily cause partial electromagnetic protection failure

The wave-absorbing layer in traditional building structures is mostly a single-layer structure, and it is difficult to meet the electromagnetic protection design requirements of optimal impedance matching and absorption efficiency in a wide frequency band.

Moreover, the construction steps of the electromagnetic protection structure manufactured by traditional technology are cumbersome. For complex construction environments, high construction level requirements and complex shape building structures, it is difficult to ensure the quality of electromagnetic protection, which in turn significantly reduces its electromagnetic protection effect.

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