Enhanced thermal conductivity in Si3N4 ceramic with the addition of Y2Si4N6C |
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| Authors: | Yinsheng Li Ha‐Neul Kim Haibo Wu Mi‐Ju Kim Jae‐Woong Ko Young‐Jo Park Zhengren Huang Hai‐Doo Kim |
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| Affiliation: | 1. Engineering Ceramics Research Group, Korea Institute of Materials Science, Changwon, Korea;2. State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai, China |
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| Abstract: | Si3N4 ceramic was densified at 1900°C for 12 hours under 1 MPa nitrogen pressure, using MgO and self‐synthesized Y2Si4N6C as sintering aids. The microstructures and thermal conductivity of as‐sintered bulk were systematically investigated, in comparison to the counterpart doped with Y2O3‐MgO additives. Y2Si4N6C addition induced a higher nitrogen/oxygen atomic ratio in the secondary phase by introducing nitrogen and promoting the elimination of SiO2, resulting in enlarged grains, reduced lattice oxygen content, increased Si3N4‐Si3N4 contiguity and more crystallized intergranular phase in the densified Si3N4 specimen. Consequently, the substitution of Y2O3 by Y2Si4N6C led to a great increase in ~30.4% in thermal conductivity from 92 to 120 W m?1 K?1 for Si3N4 ceramic. |
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| Keywords: | microstructure silicon nitride thermal conductivity yttrium silicon carbonitride |
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