Dresden 2003 – wissenschaftliches Programm
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M: Metallphysik
M 8: Quasikristalle II
M 8.2: Vortrag
Montag, 24. März 2003, 12:00–12:15, IFW B
Formation of quasicrystals and related phases in the Al-Ni-(Fe,Ru) alloy systems — •Shaobo Mi1,2 and Benjamin Grushko1 — 1IFF, Forschungszentrum Juelich GmbH, D-52425 Juelich, Germany — 2Dept. of Materials Engineering, Dalian University of Technology, Dalian 116024, PR China
The Al-rich part of the Al-Ni-Ru phase diagram was investigated between 700 and 1100C by scanning and transmission electron microscopy, powder X-ray diffraction and differential thermal analysis. The system contains a stable ternary decagonal (D) quasicrystalline phase with 1.6 nm periodicity and four stable ternary periodic phases. The D-phase is formed in a small compositional range around about Al73Ni11Ru16 by a peritectic reaction at about 1050C and is stable until at least 700C. Its composition slightly depends on temperature. Neither stable D-phase with 0.4 nm periodicity nor stable icosahedral phase reported in the literature were found in our as-cast and thermally annealed samples. The results on Al-Ni-Ru are compared to those on Al-Ni-Fe (Fe and Ru belong to the same column in the periodic table). They are discussed with the respect to the stabilization of binary metastable quasicrystals by a third element.