ICMCTF2017 Session TSP: Symposium TS Poster Session

With excellent mechanical, chemical, and electronic properties, carbon-based thin films have drawn much attention as field emitter candidates in the past few years. Since amorphous carbon (a-C) films don’t have outstanding characteristics on s and emission currents, metals are often doped in a-C films to improve the field emission characteristics . Graphene exhibits lower s and larger emission currents, but the emitters are easy to be destroyed under high voltages. Therefore, embedding graphene nanocrystallites in the surfaces and interior structures of a-C film s could be a potential method to improve field emission characteristics of a-C films.

Self-healing ceramics are novel materials that have the ability to restore mechanical properties of cracked materials through annealing. This research focuses on the self-healing ability of zirconium carbide based nano-composites. Zirconium carbide is a stable compound and is commonly used in harsh environments, such as those encountered in space and aerospace applications. A Vickers Hardness Tester was used to inflict small diamond shaped cracks in the sample. The sample was then self-healed through heating at 1100°C for four hours and analyzed using scanning electron microcopy and x-ray diffraction to determine the chemical and structural changes that occurred at the crack site. Three sample compositions were tested for their self-healing ability in this study, namely ZrC/SiC/Y₂O₃, ZrC/Al₂O₃/Y₂O₃, and ZrC/Si₃N₄/Y₂O₃. Sintered and unsintered samples of the same composition were compared to each other. The sintered samples were heated to 1000°C for three hours. The introduction of Fe₂O₃ to ZrC/SiC/Y₂O₃ interestingly was found to yield tubular whiskers when sintered.