TY - JOUR
T1 - 3D local atomic structure evolution in a solidifying Al-0.4Sc dilute alloy melt revealed in operando by synchrotron X-ray total scattering and modelling
AU - Huang, Shi
AU - Luo, Shifeng
AU - Qin, Ling
AU - Shu, Da
AU - Sun, Baode
AU - Lunt, Alexander J.G.
AU - Korsunsky, Alexander M.
AU - Mi, Jiawei
N1 - Funding Information:
The authors would like to acknowledge the synchrotron X-ray beam time awarded by beamline I15 of Diamond Light Source (experimental No. EE20883-1); access to the University of Hull Supercomputer, Viper, and the technical support. Da Shu and Baode Sun also would like to acknowledge the financial support from the National Natural Science Foundation of China (Nos. U1832183 and 51821001). Shi Huang and Shifeng Luo also would like to acknowledge the financial support from the China Scholarship Council for their PhD study at University of Hull.
PY - 2022/4/1
Y1 - 2022/4/1
N2 - Using synchrotron X-ray total scattering and empirical potential structure refinement modelling, we studied systematically in operando condition the disorder-to-order local atomic structure transition in a pure Al and a dilute Al-0.4Sc alloy melt in the temperature range from 690 °C to 657 °C. In the liquid state, icosahedral short-range ordered Sc-centred Al polyhedrons form and most of them with Al coordination number of 10–12. As the melt is cooled to the semisolid state, the most Sc-centred polyhedrons become more connected atom clusters via vertex, edge and face-sharing. These polyhedrons exhibit partially icosahedral and partially face-centred-cubic symmetry. The medium-range ordered Sc-centred clusters with face-sharing are proved to be the “precursors” of the L12 Al3Sc primary phases in the liquid-solid coexisting state.
AB - Using synchrotron X-ray total scattering and empirical potential structure refinement modelling, we studied systematically in operando condition the disorder-to-order local atomic structure transition in a pure Al and a dilute Al-0.4Sc alloy melt in the temperature range from 690 °C to 657 °C. In the liquid state, icosahedral short-range ordered Sc-centred Al polyhedrons form and most of them with Al coordination number of 10–12. As the melt is cooled to the semisolid state, the most Sc-centred polyhedrons become more connected atom clusters via vertex, edge and face-sharing. These polyhedrons exhibit partially icosahedral and partially face-centred-cubic symmetry. The medium-range ordered Sc-centred clusters with face-sharing are proved to be the “precursors” of the L12 Al3Sc primary phases in the liquid-solid coexisting state.
KW - Aluminium-Scandium alloy, Synchrotron X-ray total scattering
KW - Empirical Potential Structure Refinement
KW - In Operando Study of Solidification
KW - Liquid Atomic Structure
UR - http://www.scopus.com/inward/record.url?scp=85122503538&partnerID=8YFLogxK
U2 - 10.1016/j.scriptamat.2021.114484
DO - 10.1016/j.scriptamat.2021.114484
M3 - Article
AN - SCOPUS:85122503538
VL - 211
JO - Scripta Materialia
JF - Scripta Materialia
SN - 1359-6462
M1 - 114484
ER -