The precipitation behaviour of a hexagonal two-dimensional aperiodic phase in Al-rich Al-Mn-Be alloy has been investigated. Upon heat treatment at temperatures above 450°C, the icosahedral phase formed in a conventionally cast Al-2.5at.% Mn-3at.% Be alloy transforms into the stable hexagonal HI phase. The solute partitioning during transformation leads to the precipitation of a hexagonal two-dimensional aperiodic approximant phase (H′ phase). The precipitates have an orientation relationship with the α-Al matrix. The similarity of the diffraction features indicates that the hexagonal two-dimensional aperiodic structure of the H′ phase is an intermediate structure between the true sixfold quasiperiodic structure and the hexagonal structure of the crystalline counterpart H1 phase.
Bibliographical noteFunding Information:
ACKNOWLEDGEMENTS The authors are grateful for the financial support by the Creative Research Initiatives of the Korean Ministry of Science and Technology.
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics