Berlin 2005 – wissenschaftliches Programm

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M: Metallphysik

M 2: Flüssige und amorphe Metalle I

M 2.3: Vortrag

Freitag, 4. März 2005, 11:00–11:15, TU H111

Bulk Metallic Glass Formation in ZrCuFeAl alloys — •K.F. Jin and J. F. Löffler — Laboratory of Metal Physics and Technology, ETH Zürich, 8093 Zürich, Switzerland

We present a series of Ni-free Zr-based bulk metallic glasses where the critical casting thickness (in rod-shape) reaches values of up to 13 mm in diameter. The glass-forming region of this family of alloys is very extensive, and nearly 15 percent of their Zr or Cu content may be varied while still maintaining a critical casting thickness of 1 mm. The alloys were investigated via x-ray diffraction (XRD), small-angle neutron scattering (SANS) and differential scanning calorimetry (DSC). XRD and SANS confirm a glassy structure, while DSC determines a calorimetric glass transition between 665 K and 687 K and an undercooled liquid region extending up to 86 K. Mechanical tests performed on the glassy alloys reveal a tensile yield strength of 1.7 GPa and an elastic limit of 2.25 percent. In addition, crystallization studies show the formation of a nanometer-sized icosahedral phase with a quasilattice constant of 4.76 angstrom. The superior properties of these bulk metallic glasses, their glassy structure and the fact that they are Ni free, make them interesting candidates for biomedical applications.

Supported by ESM (Entwicklungsfonds Seltene Metalle)