Details

Autor(en) / Beteiligte

• He, Yong-Qin
• Li, Xiao-Yun
• Zhang, Jing-Xian
• Li, Xiao-Guang

Titel

In situ Pyrolyzed Carbon on the Property of AlN-based Microwave Attenuation Ceramics

Ist Teil von

• Wu ji cai liao xue bao, 2018-01, Vol.33 (4), p.421

Ort / Verlag

Beijing: Chinese Academy of Sciences

Erscheinungsjahr

2018

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• Carbon materials exhibit excellent microwave absorbing properties. However, it is difficult to disperse carbon homogeneously in the ceramic substrate. In this study, carbon was introduced into Al N matrix by addition of phenolic resin followed by pyrolysis process. The effects of phenolic resin content on sintering behavior, microstructure, thermal conductivity and dielectric properties of Al N ceramics were investigated. It was found that phenolic resin derived carbon could effectively promote the densification of Al N ceramics and reduce the sintering temperature. Relative density of the Al N ceramics reached 99.26% after sintering at 1700℃ with addition of 3 wt% phenolic resin. In addition, it was found that the presence of phenolic resin derived carbon can effectively improve the thermal conductivity of the ceramics. The dielectric properties were also improved due to the carbon films formed in the pores and at Al N grain boundaries. With addition of 6 wt% phenolic resin, Al N ceramics showed high thermal conductivity of 135.1 W/(m?K) and excellent microwave attenuation properties(the dielectric loss was 0.3 at X-band), which were perspective candidates for possible applications in high power microwave vacuum electron devices.