Premium
High/Low Modulus Si 3 N 4 ‐BN Composite for Improved Electrical and Thermal Shock Behavior
Author(s) -
MAZDIYASNI K. S.,
RUH ROBERT
Publication year - 1981
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.1151-2916.1981.tb09881.x
Subject(s) - materials science , thermal shock , composite material , hot pressing , thermal expansion , microstructure , composite number , modulus , dielectric , phase (matter) , thermal , young's modulus , atmospheric temperature range , thermodynamics , chemistry , physics , optoelectronics , organic chemistry
High‐density Si 3 N 4 +6% CeO 2 composites with 5 to 50% BN were fabricated by hot‐pressing. BN remained as a discrete phase. Dielectric constants were 4 to 8 and loss tangents were 0.0008 to 0.06 for the room temperature to 1100°C range for compositions with 10 to 50% BN. Thermal‐expansion values perpendicular to the hot‐pressing direction were somewhat less than those of hot‐pressed Si 3 N 4 +6% CeO 2 . Flexure strengths at room temperature were considerably lower than those of hot‐pressed Si 3 N 4 +6% CeO 2 but values at 1000°, 1250°, and 1400°C in air were only slightly lower. Young's modulus values were found to decrease with increasing BN content at all temperatures. Better thermal shock resistance was found than for commercial hot‐pressed Si 3 N 4 .