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Synthesis and Electromagnetic Shielding Property of Pyrolytic Carbon‐Silicon Nitride Ceramics with Dense Silicon Nitride Coating
Author(s) -
Li Xiangming,
Zhang Litong,
Yin Xiaowei
Publication year - 2012
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1551-2916.2011.04930.x
Subject(s) - pyrolytic carbon , silicon nitride , materials science , chemical vapor infiltration , chemical vapor deposition , coating , ceramic , nitride , silicon , composite material , layer (electronics) , metallurgy , chemical engineering , nanotechnology , pyrolysis , engineering
Pyrolytic carbon‐silicon nitride ceramics with dense silicon nitride coating ( PyC‐Si 3 N 4 /Si 3 N 4 ) were fabricated by chemical vapor infiltration of PyC into porous Si 3 N 4 ceramics combined with chemical vapor deposition of Si 3 N 4 at their surface. The electromagnetic shielding effectiveness ( SE ) of PyC‐Si 3 N 4 /Si 3 N 4 increases with the increase of PyC content and specimen thickness. When the content of PyC is 11.7 vol% and the thickness of specimen is 2.8 mm, the mean total SE of PyC‐Si 3 N 4 /Si 3 N 4 reaches 43.2 dB in the frequency range of 8.2–12.4 GHz. Due to the excellent sealing effect of dense Si 3 N 4 coating, the mean total SE of PyC‐Si 3 N 4 /Si 3 N 4 remains unchanged even after oxidation at 1100°C for 10 h in air.