TITLE:
Icosahedral Quasicrystal Layer Observed on λ Phase in Al-Cu-Fe Alloy
AUTHORS:
Andrew Baker, Matthew Caputo, Helen Hampikian, Luke Simpson, Chunfei Li
KEYWORDS:
Icosahedral Quasicrystal, Orientation Relationship, Electron Back Scattering Diffraction, Interface
JOURNAL NAME:
Materials Sciences and Applications,
Vol.8 No.7,
June
28,
2017
ABSTRACT: Icosahedral quasicrystals display irregular shape if
it is embedded in bulk material. If it has free surface, it has well-defined
facets, reflecting its unique 5-, 3-, and 2-fold rotational symmetries. In this
study, an Al-Cu-Fe alloy with nominal composition of Al65Cu20Fe15 was prepared by arc melting and the microstructure was studied by using
Scanning Electron Microscope, Energy Dispersive X-ray Spectroscopy, and
Electron Back Scattering Diffraction (EBSD). On the surface of λ crystalline
phase, an extra layer is found. EBSD from this layer revealed 5-, 3-, and
2-fold rotational symmetries, demonstrating the icosahedral quasicrystalline
structure. Further, it has been found that the icosahedral quasicrystalline extra layer and the λ substrate have orientation
relationship revealed by the coincidences of Kikuchi bands and poles on the
EBSD patterns. This report is important to future studies regarding the
formation of icosahedral quasicrystalline phase and thin film preparation
related to icosahedral quasicrystalline phase.