|About this Abstract
||1st World Congress on High Entropy Alloys (HEA 2019)
||High Entropy Alloys 2019
||P12: Hydrogen Sorption in MgTiNbCr0.5Mn0.5Ni0.5 High Entropy Alloy Synthesized Using High Energy Ball Milling (HEBM)
||Felipe Marques, Haroldo Cavalcanti Pinto, Walter JosÚ Botta, Guilherme Zepon
|On-Site Speaker (Planned)
A new HEA, namely MgTiNbCr0.5Mn0.5Ni0.5, was synthesized by HEBM for 24 hours in two conditions: i) under 0.07 MPa of argon ii) under 3.0 MPa of hydrogen. In the former, the HEA presented BCC solid solution combined with metallic manganese and chromium; in the later, the HEA exhibited major FCC high entropy hydride phase (MH2 with CaF2-type structure) with small fraction of metallic chromium. Both samples were subjected to in situ synchrotron radiation X-ray diffraction to analyze phase transitions during hydrogen absorption/desorption. It was found that the BCC phase absorbed hydrogen by solid solution with a change of structure volume of ΔV=5.42 Å3(15.3%) without phase transition. Yet, the high entropy hydride undergone phase transition from FCC to BCC during hydrogen desorption at 400 ░C. This results show that this HEA is able to store hydrogen reversibly, although the transition from BCC to FCC during absorption still need further investigation.