|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Mechanical Behavior of Nanostructured Materials
||L-126: The Influence of Glassy Phase on the Crack Healing Efficiency of Silicon Carbide/Spinel Ceramic
||Fariborz Tavangarian, Guoqiang Li
|On-Site Speaker (Planned)
Crack self-healing behavior of SiC/MgAl2O4 nanocomposite was evaluated as a function of time, temperature and atmosphere. In the presence of oxygen at high temperatures, SiC reacts with oxygen to form SiO2 which is accompanied with about 80% volume expansion. On the other hand, the formed silica reacts with the matrix and produces some transition compounds which can rebond crack walls together. The results showed that complete healing can be obtained in the specimens sintered at 1550 °C for 1 min. Detailed investigation revealed that the formation of aluminosilicate glassy phase is responsible for the complete recovery of mechanical properties. At around 1550 °C, enstatite dissociated into forsterite and silica rich liquid which reacted with spinel and produced a glassy phase which can flow into the cracks and heal the structure. This glassy phase flows to the location of the cracks and acts as a glue. With decreasing the temperature this glassy phase provides a strong physical and chemical bonds between the crack walls and hence enhance the self-healing efficiency of the composite.
||Planned: Supplemental Proceedings volume