|About this Abstract
||2018 TMS Annual Meeting & Exhibition
||High Entropy Alloys VI
||Role of Copper in Nucleation and Stabilization of Ordered L12 Precipitates in HEAs
||Bharat Gwalani, Rajarshi Banerjee
|On-Site Speaker (Planned)
A detailed investigation of precipitation of the ordered L12 (γ′) phase in three different high entropy alloy (HEA), Al0.3CoCrFeNi, Al0.3CrCuFeNi2, Al0.3Cu0.3Ti0.2CoCrFeNi, reveals the role of copper (Cu) on stabilization and precipitation of the ordered L12 (γ′) phase. Detailed characterization via coupling of scanning and transmission electron microscopy, and atom probe tomography showed novel insights into Cu clustering within the face-centered cubic matrix of this HEA, leading to heterogeneous nucleation sites for the γ′ precipitates. The subsequent partitioning of Cu into the γ′ precipitates indicates that their stabilization is due to Cu addition. The γ′ order-disorder transition temperature was determined to be ~930oC in Al0.3CrCuFeNi2 alloy based on synchrotron diffraction experiments involving in situ annealing. The growth and high temperature stability and precipitation strengthening due to the ordered intermetallic phase is confirmed via systematic investigations of samples annealed at temperatures in the range of 500 - 900°C.
||Planned: Supplemental Proceedings volume