|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||High Entropy Alloys V
||Fabrication of High-entropy Refractory Metal Carbides
||Tyler Harrington, Joshua Gild, Jian Luo, Cormac Toher, Pranab Sarker, Stefano Curtarolo, Kenneth Vecchio
|On-Site Speaker (Planned)
Bulk samples of three equiatomic, five-component, high-entropy refractory carbides were fabricated using a combination of high-energy ball milling, spark plasma sintering, and hot pressing. Each of the complex carbide compositions, including (Hf<SUB>0.2</SUB>Nb<SUB>0.2</SUB>Ta<SUB>0.2</SUB>Ti<SUB>0.2</SUB>Zr<SUB>0.2</SUB>)C, (Hf<SUB>0.2</SUB>Nb<SUB>0.2</SUB>Ta<SUB>0.2</SUB>Ti<SUB>0.2</SUB>V<SUB>0.2</SUB>)C, and (Nb<SUB>0.2</SUB>Ta<SUB>0.2</SUB>Ti<SUB>0.2</SUB>V<SUB>0.2</SUB>W<SUB>0.2</SUB>)C demonstrated virtually single-phase, solid-solution compounds and were sintered to greater than 95% theoretical density. Microstructure homogeneity was improved by subsequent 2500°C heat treatment. To select likely candidate compositions to form an entropy-stabilized material, the different configurations should have similar energies to increase the number of thermodynamically accessible states. A partial occupation method was implemented within AFLOW to automate the generation and calculation of the different configurations. The energy distributions were then used to construct a descriptor to predict the formation of these high-entropy materials. CALPHAD results were found to agree with the configuration energy range descriptor for each composition, and these carbides exhibited broad, single-phase solubility across each system, making processing easier.
||Planned: Supplemental Proceedings volume