Title: Optimal design and preparation of silicon nitride ceramic radome material with gradient porous structure

Authors: Fei Chen, Ling Li, Faqiang Yan, Qiang Shen, Lianmeng Zhang

Addresses: State Key Lab of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, PR China. ' Shandong Research and Design, Institute of Industrial Ceramics, Shandong 255031, PR China. ' Shandong Research and Design, Institute of Industrial Ceramics, Shandong 255031, PR China. ' State Key Lab of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, PR China. ' State Key Lab of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, PR China

Abstract: In this study, a gradient porous Si₃N₄ ceramic radome wall structure is promoted for broadband (1–18 GHz) application. By optimising the thickness and dielectric constant, the transmission efficiency at 1–18 GHz is calculated based on the microwave equivalent network method. Si₃N₄ ceramics with gradient porous structure are then prepared. Si₃N₄ ceramics of controlled relative density ranging 53–99% and dielectric constant ranging 3–8 are prepared by adding different additives such as ZrP₂O₇, MgO and Al₂O₃, using pressureless sintering and spark plasma sintering. The results show that Si₃N₄ ceramics is still α phase and exhibit a good gradient porous structure.

Keywords: silicon nitride; ceramic radome; gradient porous structure; high transmission efficiency; optimal design; broadband; thickness; dielectric constant; ceramics; sintering.

DOI: 10.1504/IJMPT.2010.034261

International Journal of Materials and Product Technology, 2010 Vol.39 No.1/2, pp.72 - 82

Published online: 31 Jul 2010 *

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