Dresden 2003 – wissenschaftliches Programm

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M: Metallphysik

M 7: Quasikristalle I

M 7.2: Vortrag

Montag, 24. März 2003, 10:30–10:45, IFW B

Influence of Ball Milling on Quasicrystal Formation in Zr₅₇Ti₈Nb_2.5Cu_13.9Ni_11.1Al_7.5 Melt-Spun Glassy Ribbons — •Sergio Scudino, Jürgen Eckert, Uta Kühn, and Ludwig Schultz — IFW Dresden, Institute of Metallic Materials, P. O. Box 270016, D-01171 Dresden, Germany

The influence of high-energy ball milling on the devitrification behavior of melt-spun Zr₅₇Ti₈Nb_2.5Cu_13.9Ni_11.1Al_7.5 melt-spun glassy ribbons was investigated. The devitrification of the as-spun ribbon is characterized by the formation of a metastable nanoscale quasicrystalline phase during the first stage of the crystallization process, followed by successive transformation into intermetallic compounds at higher temperatures. Conversely, in the ball-milled ribbon the primary quasicrystal formation upon devitrification is progressively suppressed with increasing milling time. The ribbon produced from previously milled ribbon no longer shows quasicrystal formation in the first step of crystallization suggesting the absence of an as-quenched icosahedral short-range order. The role of typical impurities such as iron and oxygen, which are introduced during milling, for affecting the crystallization behavior is critically discussed. This work was supported by the German Science Foundation under grant Ec 111/10-1.