TY - JOUR
T1 - Clarification of phase stability and oxidation mechanism for TiZrHfTaX (X = Ta, Cr) using thermodynamic calculation
AU - Komiya, Yuki
AU - Haginiwa, Daiki
AU - Kogo, Yasuo
AU - Arai, Yutaro
N1 - Publisher Copyright:
© 2022, The Author(s), under exclusive licence to The Materials Research Society.
PY - 2022/11
Y1 - 2022/11
N2 - TiZrHfNbX (X = Ta, Cr) alloys were prepared as refractory high-entropy alloys (RHEAs) using an arc-melting method to investigate the differences in their oxidation behavior. Thermogravimetric analysis (TGA) and isothermal oxidation at 1200 °C for 4 h revealed that the weight gain of TiZrHfNbCr is larger than that of TiZrHfNbTa, and the preferential oxidation of Hf and Zr occurs in TiZrHfNbCr. After oxidation, complex oxides with structures (Zr, Hf)6(Nb, Ta)2O17, Ti(Nb, Ta)2O7, and Cr(Nb, Ta)O2 were formed, and these complex oxides probably acted as barriers for oxygen diffusion during oxidation. To gain in-depth understanding about the role of these oxides during oxidation, the oxidation behavior of middle- and low-entropy alloys with higher (Ti, Zr, and Hf) and lower (Nb, Ta, and Cr) Gibbs free energies of oxidation was investigated.
AB - TiZrHfNbX (X = Ta, Cr) alloys were prepared as refractory high-entropy alloys (RHEAs) using an arc-melting method to investigate the differences in their oxidation behavior. Thermogravimetric analysis (TGA) and isothermal oxidation at 1200 °C for 4 h revealed that the weight gain of TiZrHfNbCr is larger than that of TiZrHfNbTa, and the preferential oxidation of Hf and Zr occurs in TiZrHfNbCr. After oxidation, complex oxides with structures (Zr, Hf)6(Nb, Ta)2O17, Ti(Nb, Ta)2O7, and Cr(Nb, Ta)O2 were formed, and these complex oxides probably acted as barriers for oxygen diffusion during oxidation. To gain in-depth understanding about the role of these oxides during oxidation, the oxidation behavior of middle- and low-entropy alloys with higher (Ti, Zr, and Hf) and lower (Nb, Ta, and Cr) Gibbs free energies of oxidation was investigated.
UR - http://www.scopus.com/inward/record.url?scp=85137507236&partnerID=8YFLogxK
U2 - 10.1557/s43580-022-00336-w
DO - 10.1557/s43580-022-00336-w
M3 - Article
AN - SCOPUS:85137507236
SN - 2059-8521
VL - 7
SP - 841
EP - 847
JO - MRS Advances
JF - MRS Advances
IS - 31
ER -