Environmental stability of additively manufactured siliconized silicon carbide for applications in hybrid energy systems |
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Authors: | Bola Yoon Dylan Richardson Saad A Jajja Corson L Cramer Michael J Lance Kashif Nawaz Edgar Lara-Curzio |
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Affiliation: | 1. Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA;2. Nuclear Energy and Fuel Cycle Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA;3. Buildings and Transportation Science Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA;4. Manufacturing Science Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA;5. Energy Science & Technology Directorate, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA |
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Abstract: | A key consideration for the successful operation of hybrid energy systems will be the environmental stability of materials used for their construction, particularly when experiencing service environments containing water vapor at high temperatures. Here, we report results from the characterization of siliconized silicon carbide (Si-SiC) prepared via binder jet additive manufacturing and reactive silicon melt infiltration after being exposed to environments representative of those in solid oxide fuel cell (SOFC) anodes, and to exhaust gases inside a microturbine operating on natural gas. In both cases, it was found that oxide scales formed on the surface and that these scales were dense, continuous, and well-bonded to the substrates, although there was evidence of transverse and longitudinal cracking most likely as a result of mismatches in the thermal expansion of the scale and the substrate. Measured values of the thickness of the oxide scale were compared to those predicted by parabolic oxidation kinetics of silicon, but the potential effects of silica volatilization induced by water vapor, and silica reduction when exposed to hydrogen are discussed. The overall results showed that the oxide scale is expected to be protective under the conditions of hybrid power generation systems. |
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Keywords: | oxidation printing silicon silicon carbide volatilization |
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