Regensburg 2002 – wissenschaftliches Programm

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M: Metallphysik

M 12: Amorphe und metastabile Metalle III

M 12.2: Fachvortrag

Dienstag, 12. März 2002, 14:45–15:00, H4

Thermal stability and crystallization behaviour of mechanically alloyed Zr-Cu-Al-Ni-C glassy powders — •Stefano Deledda, Jürgen Eckert, and Ludwig Schultz — IFW Dresden, Institute of Metallic Materials, P.O. Box 270016, 01171 Dresden

Glassy (Zr_0.55Cu_0.30Al_0.10Ni_0.05)_100−xC_x (x = 0, 1, 2, 3, 4) powders were prepared by mechanical alloying. Differential scanning calorimetry was performed, both in isochronal and isothermal mode, in order to investigate the thermal stability of the glass and the supercooled liquid, as well as the crystallization behaviour. Kissinger’s method and Arrhenius’ equation were applied to estimate the activation energies for crystallization while the crystallization kinetics were studied in the framework of the Johnson-Mehl-Avrami model. X-Ray Diffraction analysis was carried out to examine the metastable and equilibrium crystalline phases which form as crystallization products. The results are compared and discussed in terms of how increasing carbon contents affect the chemical and topological short-range order as well as the viscous flow behaviour of the alloy.