|About this Abstract
||1st World Congress on High Entropy Alloys (HEA 2019)
||High Entropy Alloys 2019
||Combinatorial Thin Film Approach to Develop Refractory BCC HEAs with Improved Ductility
||Taohid Bin Nur Tuhser, Daryl Chrzan, Andrew Minor, Mark Asta, Thomas John Balk
|On-Site Speaker (Planned)
||Taohid Bin Nur Tuhser
The optimum balance between ductility and hardness of refractory high entropy alloys (RHEAs) is strongly dependent on alloy composition, which need not be exactly equiatomic. In this study, 2D composition gradients of VNbMoTaW and VNbMoTaWHf thin films were made by magnetron sputtering. Replacing Mo with Nb in the same system is expected to improve ductility. X-ray diffraction and energy dispersive x-ray spectroscopy were used to develop a map of alloy phase space. More than 30 local compositions were reported with respective crystal structures, from each thin film. We identified a set of compositions with a single-phase BCC structure. Also, the BCC crystal structure was retained while replacing Mo with Nb. Bulk samples of selected compositions were prepared using vacuum arc melting. Mechanical properties, including hardness and ductility, were investigated with these bulk samples to establish appropriate composition-structure-property relationships.