TY - JOUR
T1 - Thermodynamic stabilization of crystalline silicon carbide polymer-derived ceramic fibers
AU - Leonel, Gerson J.
AU - Mujib, Shakir Bin
AU - Singh, Gurpreet
AU - Navrotsky, Alexandra
N1 - Publisher Copyright:
© 2022 The Authors. International Journal of Ceramic Engineering & Science published by Wiley Periodicals LLC. on behalf of the American Ceramic Society.
PY - 2022/9
Y1 - 2022/9
N2 - Three crystalline SiC fibers were studied: Tyranno, Hi-Nicalon, and Sylramic. Thermodynamic stability of the SiC fibers was determined by high temperature oxide melt solution calorimetry. Results shed light on the thermodynamic penalty or benefit associated with microstructural modification of the ceramic fibers, and how energetics correlate to mechanical properties. Enthalpies of formation from components (SiC, SiO2, Si3N4, and C, ∆H°f,comp) for Tyranno, Hi-Nicalon, and Sylramic are −12.05 ± 8.71, −58.75 ± 6.93, and −71.10 ± 8.71 kJ/mol Si, respectively. The microstructure in Sylramic offers the greatest stabilizing effect, thus resulting in its much more exothermic enthalpy of formation relative to elements and crystalline components. In contrast, the microstructure in Tyranno offers the least stabilization. The thermodynamic stability of the fibers increases with increasing mixed bonding (Si bonded to both C and O). From mechanical testing, Young's moduli of Tyranno, Hi-Nicalon, and Sylramic are 112, 205, and 215 GPa, respectively. Greater thermodynamic stability is correlated with a higher Young's modulus.
AB - Three crystalline SiC fibers were studied: Tyranno, Hi-Nicalon, and Sylramic. Thermodynamic stability of the SiC fibers was determined by high temperature oxide melt solution calorimetry. Results shed light on the thermodynamic penalty or benefit associated with microstructural modification of the ceramic fibers, and how energetics correlate to mechanical properties. Enthalpies of formation from components (SiC, SiO2, Si3N4, and C, ∆H°f,comp) for Tyranno, Hi-Nicalon, and Sylramic are −12.05 ± 8.71, −58.75 ± 6.93, and −71.10 ± 8.71 kJ/mol Si, respectively. The microstructure in Sylramic offers the greatest stabilizing effect, thus resulting in its much more exothermic enthalpy of formation relative to elements and crystalline components. In contrast, the microstructure in Tyranno offers the least stabilization. The thermodynamic stability of the fibers increases with increasing mixed bonding (Si bonded to both C and O). From mechanical testing, Young's moduli of Tyranno, Hi-Nicalon, and Sylramic are 112, 205, and 215 GPa, respectively. Greater thermodynamic stability is correlated with a higher Young's modulus.
KW - fibers
KW - silicon carbide
KW - thermodynamics
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U2 - 10.1002/ces2.10153
DO - 10.1002/ces2.10153
M3 - Article
AN - SCOPUS:85138002068
SN - 2578-3270
VL - 4
SP - 315
EP - 326
JO - International Journal of Ceramic Engineering and Science
JF - International Journal of Ceramic Engineering and Science
IS - 5
ER -