Revealing the Precipitation Sequence with Aging Temperature in a Non-equiatomic AlCoCrFeNi High Entropy Alloy

• DOI: 10.1007/s11661-021-06528-7
• Publication Date: 2021-11-16T14:03:57Z
• Authors: Vickey Nandal; Bushra Harun; R. Sarvesha; Sudhanshu S. Singh; E.-Wen Huang; Yao-Jen Chang; An-Chou Yeh; Jayant Jain; Suresh Neelakantan
• Keywords: 02 engineering and technology; 0210 nano-technology

Sequential transformation in precipitate structure from L12 → B2-NiAl precipitate has been observed for Al0.5Co1.5CrFeNi1.5 alloy with the increase in aging temperature. At 650 °C, the FCC matrix contained L12 precipitates (γ′), which were transformed into ordered B2 structure precipitate at 750 °C. A coarser and more stable B2-NiAl rich precipitate has been observed for higher aging temperature (850 °C). This transformation is attributed to the higher thermodynamic stability of B2-NiAl precipitates overcoming the nucleation barrier at higher temperatures.