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A strategy for fabricating anisotropic SI 3 N 4 ceramics with controllable mechanical and thermal properties
Author(s) -
Zhao Zhe,
Lu Xugao,
Zhou Guoxiang,
Yang Yitian,
Lin Kunpeng,
Yang Zhihua,
Jia Dechang,
Zhou Yu
Publication year - 2020
Publication title -
international journal of applied ceramic technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.4
H-Index - 57
eISSN - 1744-7402
pISSN - 1546-542X
DOI - 10.1111/ijac.13618
Subject(s) - materials science , anisotropy , ceramic , thermal conductivity , composite material , sintering , fracture toughness , thermal , thermal diffusivity , work (physics) , grain size , mechanical engineering , optics , thermodynamics , physics , engineering
Heat dissipation material with programmable anisotropic property is very challenging, yet can realize the controllable thermal diffusion for heating device. In this work, anisotropic Si 3 N 4 ceramics with oriented grains are prepared to adjust and improve the mechanical and thermal properties under the applied stress field by rolling film forming technology. Through the design of the sintering aids in the process of liquid‐phase sintering, the orientation degree of the Si 3 N 4 grains is programmable as well as the mechanical property and the thermal property of the Si 3 N 4 ceramics. As a consequence, the obtained Si 3 N 4 ceramics show significant anisotropy in mechanical properties and thermal conductivity. The typical fracture toughness and thermal conductivity along the grain orientation direction are 10.6 MPa⋅m 1/2 and 45.45 W/(m⋅K) while they are 4.5 MPa⋅m 1/2 and 66.42 W/(m⋅K) in the direction perpendicular to the oriented grain, respectively. This grain orientation method paves the way for the thermal performance design and the production of programmable heat dissipation material.