|About this Abstract
||2018 TMS Annual Meeting & Exhibition
||Ultrafine-grained Materials X
||Thermodynamical Instability of a Single-phase, Nanocrystalline TiZrNbHfTa Alloy and its Impact on the Mechanical Properties
||Benjamin Schuh, Bernhard Völker, Juraj Todt, Loic Perriere, Jean-Philippe Couzinié, Anton Hohenwarter
|On-Site Speaker (Planned)
A TiZrNbHfTa high-entropy alloy was subjected to high-pressure torsion in order to introduce a nanocrystalline microstructure and subsequently heat treated between 300°C and 1100°C to evaluate the thermodynamical stability. Isochronal heat treatments performed for 1 hour resulted in a hardness increase from 420 HV1 for the as-processed state to 530 HV1 for an annealing temperature of 500°C. To clarify this annealing response analysis via electron microscopy, x-ray diffraction and tensile testing was performed, complemented by Thermo-Calc simulations. A phase decomposition of the single-phase high-entropy alloy into a NbTa-rich and a ZrHf-rich phase is the main reason for the property changes. The obtained results give valuable new insights into the phase stability of the TiZrNbHfTa alloy and highlight the advantages of obtaining a nanocrystalline microstructure to speed up such studies by introducing an abundance of fast diffusion pathways and preferential nucleations sites in the form of grain boundaries.
||Planned: Supplemental Proceedings volume