Sintered Reaction-Bonded Silicon Nitride with High Thermal Conductivity and High Strength

Authors: Zhou, You¹; Zhu, Xinwen¹; Hirao, Kiyoshi¹; Lences, Zoltan²

Source: International Journal of Applied Ceramic Technology, Volume 5, Number 2, March 2008 , pp. 119-126(8)

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Abstract:

Sintered reaction-bonded silicon nitride (SRBSN) materials were prepared from a high-purity Si powder doped with Y₂O₃ and MgO as sintering additives by nitriding at 1400°C for 8 h and subsequently postsintering at 1900°C for various times ranging from 3 to 24 h. Microstructures and phase compositions of the nitrided and the sintered compacts were characterized. The SRBSN materials sintered for 3, 6, 12, and 24 h had thermal conductivities of 100, 105, 117, and 133 W/m/K, and four-point bending strengths of 843, 736, 612, and 516 MPa, respectively. Simultaneously attaining thermal conductivity and bending strength at such a high level made the SRBSN materials superior over the high-thermal conductivity silicon nitride ceramics that were prepared by sintering of Si₃N₄ powder in our previous works. This study indicates that the SRBSN route is a promising way of fabricating silicon nitride materials with both high thermal conductivity and high strength.

Document Type: Research article

DOI: http://dx.doi.org/10.1111/j.1744-7402.2008.02187.x

Affiliations: 1: National Institute of Advanced Industrial Science and Technology (AIST), Nagoya 463-8560, Japan 2: Institute of Inorganic Chemistry, Slovak Academy of Sciences, SK-845 36 Bratislava, Slovakia

Publication date: 2008-03-01