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M: Metallphysik

M 33: Postersitzung

M 33.11: Poster

Donnerstag, 29. März 2001, 15:15–19:00, Foyer S4, CCH

Hydrogenation and its effect on the crystallisation behaviour of Zr₅₅Cu₃₀Al₁₀Ni₅ metallic glass — •Nahla Ismail, Margitta Uhlemann, Annett Gebert, Jürgen Eckert, and Ludwig Schultz — IFW Dresden, Postfach 27 00 16, D-01171 Dresden, Germany

The effect of hydrogen on the physical properties and crystallisation behaviour of Zr₅₅Cu₃₀Al₁₀Ni₅ metallic glass is of interest as it contains early and late transition elements. Melt-spun ribbons are electrochemically charged to different hydrogen-to-metal (H/M) ratios, from 0.029 to 0.95. Thermal desorption analysis (TDA), is used to follow the effusion of hydrogen after charging the ribbons, the thermal stability of uncharged and charged ribbons is investigated by differential scanning calorimetry (DSC), using 20 K/min as a heating rate. X-ray diffraction is used to detect the crystalline phases formed for the differently charged and uncharged Zr₅₅Cu₃₀Al₁₀Ni₅ metallic glass ribbons. The thermal stability of the charged ribbons deteriorates in a way that the supercooled liquid region is highly reduced. Hydrogen is found to effuse from the high energy interstitial sites below 623 K. Above 623 K crystallisation of zirconium hydride takes place followed by partial desorption of the different hydride phases. The number of free Zr atoms are depleted in the amorphous matrix due to the formation of Zr-hydride phases. This, in return, leads to the formation of crystalline phases poor in Zr-content.