Berlin 2005 – wissenschaftliches Programm

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M: Metallphysik

M 20: Intermetallische Phasen I

M 20.2: Vortrag

Samstag, 5. März 2005, 09:30–09:45, TU H2038

Mechanical spectroscopy of high pressure torsion (HPT) deformed Fe₃Al based alloys — •T.S. Pavlova^1,2, I.S. Golovin², H.-R. Sinning², and R.Z. Valiev³ — ¹Physics of Metals Department of Tula State University, Lenin ave. 90, Tula, Russia — ²TU Braunschweig, Institut fuer Werkstoffe, Langer Kamp 8, D-38106 Braunschweig — ³Institute of Physics of Advanced Materials, Ufa State Aviation Technical University, Russia

The method of mechanical spectroscopy (especially internal friction measurements) is known as an effective tool for studying dislocation behaviour in deformed metals. However, for brittle intermetallic compounds like Fe₃Al, a problem is that deformation at room temperature is hardly possible by ordinary methods but requires special techniques like, for instance, high pressure torsion (HPT).

Several internal friction peaks were distinguished in HPT Fe₃Al-based alloys. Most of them are analogous to those found in deformed and irradiated pure iron, where they are known to be caused by dislocations. In HPT Fe-Al specimens, these peaks are significantly reduced already by moderate heat treatments, including even the unavoidable tempering during the measurements themselves. It is notable that using these internal friction peaks, earlier stages of annealing processes in HTP materials can be detected than by other methods, which show annealing effects only at higher temperatures. Preliminary interpretations of these peaks will be presented.