TY - JOUR
T1 - Thermal stress relaxation creep and microstructural evolutions of nanostructured SiC ceramics by liquid phase sintering
AU - Shimoda, Kazuya
AU - Kondo, Sosuke
AU - Hinoki, Tatsuya
AU - Kohyama, Akira
PY - 2010/9/1
Y1 - 2010/9/1
N2 - We explored the thermal relaxation creep characteristics of nanostructured SiC ceramics by bend stress relaxation (BSR) method. The effects of the differences in microstructure and secondary phases by liquid phase sintering at 1800 or 1900°C were especially discussed, based on microstructural evolutions during the creep. The creep was characterized by the BSR ratio (m) of ∼0.80 up to 1200°C, and the proportion of amorphous phase as a secondary phase was related to the creep resistance at 1300°C. The microstructural evolutions during the creep consisted firstly in the re-distribution of amorphous phase, probably as a consequence of its viscous flow, and secondly in an extensive nucleation and growth of cavities. Furthermore, the former enhanced inter-diffusion of Al-Y among intergranular areas above the ternary eutectic temperature, which caused the significantly reduced creep resistance, and the latter reflected the crystalline YAG decomposition as another secondary phase near 1500°C.
AB - We explored the thermal relaxation creep characteristics of nanostructured SiC ceramics by bend stress relaxation (BSR) method. The effects of the differences in microstructure and secondary phases by liquid phase sintering at 1800 or 1900°C were especially discussed, based on microstructural evolutions during the creep. The creep was characterized by the BSR ratio (m) of ∼0.80 up to 1200°C, and the proportion of amorphous phase as a secondary phase was related to the creep resistance at 1300°C. The microstructural evolutions during the creep consisted firstly in the re-distribution of amorphous phase, probably as a consequence of its viscous flow, and secondly in an extensive nucleation and growth of cavities. Furthermore, the former enhanced inter-diffusion of Al-Y among intergranular areas above the ternary eutectic temperature, which caused the significantly reduced creep resistance, and the latter reflected the crystalline YAG decomposition as another secondary phase near 1500°C.
KW - Creep
KW - Microstructural evolution
KW - SiC
KW - Sintering
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U2 - 10.1016/j.jeurceramsoc.2010.04.035
DO - 10.1016/j.jeurceramsoc.2010.04.035
M3 - Article
AN - SCOPUS:77953960079
VL - 30
SP - 2643
EP - 2652
JO - Journal of the European Ceramic Society
JF - Journal of the European Ceramic Society
SN - 0955-2219
IS - 12
ER -