TY - JOUR
T1 - Unraveling the formation of L12 nano-precipitates within the FCC-phase in AlCoCrFeNi2.1 eutectic high entropy alloy
AU - Charkhchian, J.
AU - Zarei-Hanzaki, A.
AU - Moshiri, A.
AU - Schwarz, T. M.
AU - Lawitzki, R.
AU - Schmitz, G.
AU - Schell, N.
AU - Shen, Jiajia
AU - Oliveira, J. P.
AU - Waryoba, Daudi
AU - Abedi, H. R.
N1 - Funding Information:
UIDP/50025/2020#
Atom probe and electron microscopy experiments were supported by the German Research Foundation ( Deutsche Forschungsgemeinschaft , DFG) within the collaborative research center (CRC) 1333 (project number 358283783). JS acknowledges Fundação para a Ciência e a Tecnologia (FCT - MCTES) for its financial support via the project UID/00667/2020 (UNIDEMI). JS and JPO acknowledges funding by national funds from FCT - Fundação para a Ciência e a Tecnologia , I.P., in the scope of the projects LA/P/0037/2020, UIDP/50025/2020 , Nanomodelling and Nanofabrication – i3N. JS acknowledges the China Scholarship Council for funding the Ph.D. grant (CSC NO. 201808320394 ). The authors would like to gratefully acknowledge the kind support of Prof. Daudi Waryoba, whom the Commonwealth Campuses Research Collaboration was funding through the Office of the Vice President for Commonwealth Campuses (OVPCC) and Materials Research Institute (MRI) , Pennsylvania State University (Grant # 19-349 RCDP 63988 10000 ).
Publisher Copyright:
© 2023 Elsevier Ltd
PY - 2024/3
Y1 - 2024/3
N2 - The present study investigates the formation mechanism of L12 nano-precipitates within the FCC phase during the solidification process of the AlCoCrFeNi2.1 eutectic high entropy alloy. For this purpose, advanced characterization techniques, including high-energy synchrotron X-ray diffraction, transmission electron microscopy, and atom probe tomography were employed, along with CALPHAD calculations. The solidified microstructure of the AlCoCrFeNi2.1 eutectic high entropy alloy consists of five phases: disordered FCC, disordered BCC, ordered B2 BCC, ordered L12 FCC, and sigma (σ). The dendritic regions of the disordered FCC phase were formed due to non-equilibrium solidification, while the L12 nano-precipitates were uniformly embedded within the disordered FCC matrix. These nano-precipitates were enriched with Al and Ni, while being depleted in Co, Cr, and Fe. These nano-precipitates might form around the critical temperature of 600 °C due to short-range diffusion of Al and Ni because of nucleation and growth mechanism during the solidification process.
AB - The present study investigates the formation mechanism of L12 nano-precipitates within the FCC phase during the solidification process of the AlCoCrFeNi2.1 eutectic high entropy alloy. For this purpose, advanced characterization techniques, including high-energy synchrotron X-ray diffraction, transmission electron microscopy, and atom probe tomography were employed, along with CALPHAD calculations. The solidified microstructure of the AlCoCrFeNi2.1 eutectic high entropy alloy consists of five phases: disordered FCC, disordered BCC, ordered B2 BCC, ordered L12 FCC, and sigma (σ). The dendritic regions of the disordered FCC phase were formed due to non-equilibrium solidification, while the L12 nano-precipitates were uniformly embedded within the disordered FCC matrix. These nano-precipitates were enriched with Al and Ni, while being depleted in Co, Cr, and Fe. These nano-precipitates might form around the critical temperature of 600 °C due to short-range diffusion of Al and Ni because of nucleation and growth mechanism during the solidification process.
KW - Eutectic high entropy alloy
KW - L1 nano-precipitates
KW - Ordered phase
KW - Phase transformation
KW - Solidification
UR - http://www.scopus.com/inward/record.url?scp=85180532724&partnerID=8YFLogxK
U2 - 10.1016/j.vacuum.2023.112919
DO - 10.1016/j.vacuum.2023.112919
M3 - Article
AN - SCOPUS:85180532724
SN - 0042-207X
VL - 221
JO - Vacuum
JF - Vacuum
M1 - 112919
ER -