TY - JOUR
T1 - Microstructure and EMW absorption properties of CVI Si3N4–SiCN ceramics with BN interface annealed in N2 atmosphere
AU - Xue, Jimei
AU - Yin, Xiaowei
AU - Ye, Fang
AU - Zhang, Litong
AU - Cheng, Laifei
N1 - Publisher Copyright:
© 2017 The American Ceramic Society
PY - 2018/3
Y1 - 2018/3
N2 - A kind of chemical vapor infiltration (CVI) Si3N4–BN–SiCN composite ceramic with excellent electromagnetic wave (EMW) absorbing properties is obtained by CVI BN interface and SiCN matrix on porous Si3N4 ceramics, and then annealed at high temperatures (1200°C-1500°C) in N2 atmosphere. The crystallization behavior, EMW absorbing mechanism and mechanical properties of the composite ceramics have been investigated. Results showed CVI SiCN ceramics with BN interface were crystallized in the form of nanograins, and the crystallization temperature was lower. Moreover, both EMW absorbing properties and mechanical properties of CVI Si3N4–BN–SiCN composite ceramics firstly increased and then decreased with the increase in annealing temperature due to the influence of BN interface on the microstructure and phase composition of the composite ceramics. The minimum reflection coefficient (RC) and maximum effective absorption bandwidth (EAB) of the composite ceramics annealed at 1300°C were −47.05 dB at the thickness of 4.05 mm and 3.70 GHz at the thickness of 3.65 mm, respectively. The flexural strength and fracture toughness of the composite ceramics annealed at 1300°C were 94 MPa and 1.78 MPa/m1/2, respectively.
AB - A kind of chemical vapor infiltration (CVI) Si3N4–BN–SiCN composite ceramic with excellent electromagnetic wave (EMW) absorbing properties is obtained by CVI BN interface and SiCN matrix on porous Si3N4 ceramics, and then annealed at high temperatures (1200°C-1500°C) in N2 atmosphere. The crystallization behavior, EMW absorbing mechanism and mechanical properties of the composite ceramics have been investigated. Results showed CVI SiCN ceramics with BN interface were crystallized in the form of nanograins, and the crystallization temperature was lower. Moreover, both EMW absorbing properties and mechanical properties of CVI Si3N4–BN–SiCN composite ceramics firstly increased and then decreased with the increase in annealing temperature due to the influence of BN interface on the microstructure and phase composition of the composite ceramics. The minimum reflection coefficient (RC) and maximum effective absorption bandwidth (EAB) of the composite ceramics annealed at 1300°C were −47.05 dB at the thickness of 4.05 mm and 3.70 GHz at the thickness of 3.65 mm, respectively. The flexural strength and fracture toughness of the composite ceramics annealed at 1300°C were 94 MPa and 1.78 MPa/m1/2, respectively.
KW - crystallization process
KW - CVI SiN–BN–SiCN composite ceramics
KW - EMW absorbing properties
KW - mechanical properties
UR - http://www.scopus.com/inward/record.url?scp=85031739112&partnerID=8YFLogxK
U2 - 10.1111/jace.15278
DO - 10.1111/jace.15278
M3 - 文章
AN - SCOPUS:85031739112
SN - 0002-7820
VL - 101
SP - 1201
EP - 1210
JO - Journal of the American Ceramic Society
JF - Journal of the American Ceramic Society
IS - 3
ER -