Formation of Quasicrystalline Phases and Their Close Approximants in Cast Al-Mn Base Alloys Modified by Transition Metals
The aim of the presented research was to study the influence of Cr, Co, Ni, and Cu additions on the formation of quasicrystalline particles in the 94Al-6Mn base alloy during casting at intermediate cooling rates. Based on the obtained results, Cu and Ni enhance quasicrystalline phase nucleation compared to the unmodified binary composition. In the case of Cu addition, formation of a quasicrystalline phase takes place along whole thickness of the prepared casting, but its fraction and morphology depends on the cooling rates present in different parts of the sample. Based on the previous works on the beneficial effect of Fe addition, a quaternary alloy containing both Fe and Cu was prepared to evaluate the effect of the simultaneous presence of these elements on the microstructure of the obtained castings.
A new hexagonal metastable phase coexisting with the diagonal quasicrystal in Al-Cr-Ni and Al-Mn-Ni alloys
Preparation des alliages de composition Al6Cr0,5Ni0,5 et Al4Mn0,5Ni0,5 et etude de microscopie electronique en transmission
"Superlattices" in quenched Al-Si-Mn quasicrystals.
Melt-quenched ${\mathrm{Al}}_{74}$${\mathrm{Si}}_{6}$${\mathrm{Mn}}_{20}$ and ${\mathrm{Al}}_{72}$${\mathrm{Si}}_{6}$${\mathrm{Mn}}_{22}$ alloys were found to exhibit icosahedral symmetry with a ``superlattice-like'' diffraction pattern which can be reproduced from the pattern observed in ${\mathrm{Al}}_{86}$${\mathrm{Mn}}_{14}$ quasicrystals with a scaling relationship defined by the golden mean.