Electron microscopy of an icosahedral phase in a rapidly solidified Al18Mg3Mn2 complex metallic alloy

The icosahedral quasicrystal (QC) has been found to form, along with a minor amount of α-Al, in the rapidly solidified Al18Mg3Mn2 complex metallic alloy. From the compositional analysis, the QC was found to be close to (AlMg)82Mn18. The quasilattice constant (aR = 0.4604 nm) of the QC phase suggests that it is basically an Al–Mn type of Mackay quasicrystal, which conforms to the composition analysis. The rationale behind the formation of the Al–Mg–Mn ternary quasicrystal from the T-Al18Mg3Mn2 alloy is discussed.