A kind of preparation method of porous zinc aluminate ceramics with high wave permeability

Abstract

The invention provides a method for preparing porous zinc aluminate ceramics with high wave permeability, which belongs to the technical field of functional ceramics and comprises the following steps: (1) by weight parts, 1-4 parts of basic zinc carbonate, 10-40 parts The aluminum-containing compound and 1-5 parts of lithium fluoride are mixed to obtain a mixed powder; (2) the mixed powder in step (1) is dry-pressed and then formed into a green body by cold isostatic pressing; (3) the green body is 200 ‑350°C drying and heat preservation, and then sintering and heat preservation at 1450~1650°C for 2‑4h to obtain porous zinc aluminate ceramics. The present invention utilizes zinc oxide and aluminum oxide obtained by thermal decomposition of basic zinc carbonate and aluminum-containing compounds to synthesize zinc aluminate through reaction sintering; CO released by thermal decomposition of basic zinc carbonate and aluminum-containing compounds 2 and H 2 O gas and volatilized LiF are used as pore-forming agents. The average pore size of the prepared porous ceramics is about 500nm~1.2μm, the porosity is 30%~65%, the thermal conductivity is 0.3‑1.5 W / mK, and the compressive strength is 20‑80Mpa, dielectric constant 2.0‑4.5 (frequency range 0.3~300GHz), dielectric loss 10 ‑4 ~10 ‑3 .

Description

technical field [0001] The invention belongs to the technical field of functional ceramics, and in particular relates to a method for preparing porous zinc aluminate ceramics with high wave permeability. Background technique [0002] The wave-transparent material used in the aerospace field is a multifunctional dielectric material that protects aircraft from communication and guidance in harsh environments. One of its applications is to prepare radome for aircraft (such as launch vehicles, spacecraft, missiles, etc.). With the development of aerospace technology and the needs of modern warfare, the flight Mach number of aircraft continues to increase, and the temperature and thermal shock that the radome needs to withstand are getting higher and higher, requiring it to maintain structural integrity and protection under more severe conditions. The permeability to high-temperature and high-frequency electromagnetic waves puts forward higher performance requirements for wave-tr...

AI Technical Summary

Problems solved by technology

[0004] Most of the zinc aluminate materials prepared in the prior art are dense zinc aluminate ceramics. The dense zinc aluminate ceramics have high dielectric constant, large dielectric loss, small specific surface area, high thermal conductivity, and poor wave transmission performance. , and poor thermal insulation performance

In addition, dense zinc aluminate ceramics have a high density, which will increase the weight of aerospace equipment during use and affect its flight safety, stability and energy saving