|About this Abstract
||2016 TMS Annual Meeting & Exhibition
||Phase Transformations and Microstructural Evolution
||Insights Into the Microstructure and Nucleation of the Zeta Phase in Transition Metal Carbides and Nitrides
||Hang Yu, Thompson B. Gregory, Christopher R. Weinberger
|On-Site Speaker (Planned)
When the carbon concentration is reduced from stoichiometric Tantalum Carbide (TaC), nanoscale lathes form within the TaC matrix; which is usually identified as the zeta-Ta4C3 phase. The presence of these thin lathes have a dramatic impact on the strength of the material; the stability of the zeta phase is not well known nor is the reason why they form the microstructure they do. In this talk, we examine the stability of the zeta phase in the tantalum carbides as well as other stacking fault-based or nanolamellar structures using a combination of density functional theory and analytical models. These models suggest why the thin lathes are favorable and precipitate and provide an understanding of the overall stability of the zeta phase. This model is then applied to other carbides and nitrides to understand the relative stability of the zeta phase and the microstructure it forms.
||Planned: A print-only volume