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A Novel S i 3 N 4 – S i C Ceramic Used for Volumetric Receivers
Author(s) -
Wu Jianfeng,
Liu Meng,
Xu Xiaohong,
Zhang Yaxiang,
Lao Xinbin
Publication year - 2013
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.12094
Subject(s) - materials science , thermal shock , mullite , sintering , ceramic , flexural strength , thermal expansion , composite material , thermal conductivity , composite number , microstructure , porosity , mineralogy , chemistry
S i 3 N 4 – S i C composite ceramics used for volumetric receivers were fabricated by pressureless sintering of micrometer S i C , S i 3 N 4 , andalusite, and other minor additions powders. Mechanical, thermal expansion, thermal conductivity, and thermal shock resistance properties were tested at different sintering temperatures. The best sintering temperature of optimum formula A 2 is 1360°C, and the bending strength reaches 79.60 Mpa. And moreover, its thermal expansion coefficient is 6.401 × 10 −6 /°C, thermal conductivity is 7.83 W/(m K), and no crack occurs even subjected to 30 cycles thermal shock with a bending strength increase rate of 4.72%. X ‐ray diffraction results show that the phase constituents of the sintered products mainly consist of S i C , S i 3 N 4 , mullite, and quartz. Microstructure that is most appropriate and exhibits maximal thermal shock resistance was detected using SEM . The porosity of S i 3 N 4 – S i C ceramic foam prepared from formula A 2 is 95%, which provides a rapid and steady action for the receiver. The evaluation of the present foam shows that S i 3 N 4 – S i C ceramic composite is a good candidate for volumetric receivers.