High spatial resolution thermal conductivity mapping of SiC/SiC composites [electronic resource]
Herein, silicon carbide (SiC) ceramic matrix composites are being investigated as a new generation of fuel cladding materials due to its higher accident tolerance compared to Zircaloy. Characterization of the thermal conductivity of SiC constituents and their interfaces and interphases in SiC/SiC co...
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| Format: | Government Document Electronic eBook |
| Language: | English |
| Published: |
Washington, D.C. : Oak Ridge, Tenn. :
United States. Office of the Assistant Secretary for Nuclear Energy ; Distributed by the Office of Scientific and Technical Information, U.S. Department of Energy,
2020.
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| Summary: | Herein, silicon carbide (SiC) ceramic matrix composites are being investigated as a new generation of fuel cladding materials due to its higher accident tolerance compared to Zircaloy. Characterization of the thermal conductivity of SiC constituents and their interfaces and interphases in SiC/SiC composites is needed as inputs to models of cladding performance. We used time-domain thermoreflectance (TDTR) to map the thermal conductivity with a spatial resolution of 2 æm. The SiC/SiC composite is comprised of Hi-Nicalon Type S fibers in a matrix made by chemical vapor infiltration (CVI matrix). The interphase material is a pyrolytic carbon/SiC multilayer. We report thermal conductivity maps of the SiC fiber and SiC matrix at temperatures of 25 ʻC, 90 ʻC, 164 ʻC, and 250 ʻC. The fiber has a uniform and isotropic thermal conductivity of 22 W m<sup>-1</sup> K<sup>-1</sup> at 25 ʻC; the thermal conductivity of fiber is approximately independent of temperature. The matrix thermal conductivity is not uniform and varies from 50 to 120 W m<sup>-1</sup> K<sup>-1</sup> at 25 ʻC; the thermal conductivity of the matrix scales approximately with the inverse of the square root of temperature, i.e., ? 1/T<sup>1/2</sup>. The thermal conductivity of the interphase at room temperature is 6 W m<sup>-1</sup> K<sup>-1</sup>. The calculated spatially averaged thermal conductivity of this SiC/SiC composite at 1000ʻC is 29 W m<sup>-1</sup> K<sup>-1</sup> |
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| Item Description: | Published through Scitech Connect. 09/11/2020. "Journal ID: ISSN 0022-3115." "Other: PII: S0022311520311272." Pek, Ella Kartika ; Brethauer, John ; Cahill, David G. ; Univ. of California, Oakland, CA (United States) |
| Physical Description: | Size: Article No. 152519 : digital, PDF file. |