Publication Date
9-24-2020
Department
Ames Laboratory
Campus Units
Ames Laboratory
OSTI ID+
1722886
Report Number
IS-J 10355
DOI
10.1016/j.matchar.2020.110665
Journal Title
Materials Characterization
Volume Number
170
First Page
110665
Abstract
Metallic glasses, formed from highly undercooled liquids, are ideal systems for fine tuning microstructures. The structure of the glass and the slow kinetics of devitrification provide many possible reaction pathways to form both stable and metastable phases. The Al-RE system is a prime example with many metastable-to-metastable phase transitions. Here we report observation of the transition from ε-Al60Sm11 to π-Al5Sm and fcc-Al using multiple ex-situ and in-situ methods. Ex-situ transmission electron microscope (TEM) observation demonstrates that the decomposition of ε-Al60Sm11 propagates with nearly identical spacing between fcc-Al and π-Al5Sm during isothermal annealing. In-situ high energy wide-angle X-ray diffraction (WAXD) and small-angle X-ray scattering (SAXS) methods were employed along with the DSC demonstrate the multiple phase evolution with temperature and time. A novel SAXS analysis approach is presented and validated by ex-situ TEM analysis. These results suggest that nearly monodispersed Al-nanocrystals forms at a constant rate during an isothermal annealing. Both in-situ and ex-situ observations elucidate the transition from ε-Al60Sm11 to π-Al5Sm and fcc-Al as an eutectoid reaction.
DOE Contract Number(s)
AC02-07CH11358; AC02-06CH11357
Language
en
Publisher
Iowa State University Digital Repository, Ames IA (United States)
