Berlin 2012 – scientific programme
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MM: Fachverband Metall- und Materialphysik
MM 14: Topical Session Bulk Nanostrucured Materials III - Microstructure and Characterization I
MM 14.3: Talk
Monday, March 26, 2012, 16:15–16:30, H 0107
High-pressure torsion induced open volume defects in Al-3wt%Cu investigated by positron annihilation spectroscopy — •Peter Parz1, Michael Faller2, Reinhard Pippan2, Werner Puff1, and Roland Würschum1 — 1Institut für Materialphysik, Technische Universität Graz, Petersgasse 16, 8010 Graz, Austria — 2Erich Schmid Institute of Materials Science, Austrian Academy of Sciences and Department Materials Physics, University of Leoben, A-8700 Leoben, Austria
High-pressure torsion (HPT) has proven its capability to refine metals down to grain sizes of approximately 100nm [1]. In the case of age-hardenable aluminium alloys HPT deformation may significantly affect the process of precipitation hardening. In present work [2], an Al-3wt%Cu alloy was solution treated and quenched and subsequently subjected to HPT deformation. The defect structure and its annealing behaviour have been investigated by positron annihilation lifetime spectroscopy (PALS) and the chemical sensitive method of 2-dimensional Doppler broadening spectroscopy (2d-DB). Significant deviations of the mean positron lifetime and the chemical environment of the positron trapping sites due to HPT were detected.
[1] R. Pippan, F. Wetscher, M. Hafok, A. Vorhauer, I. Sabirov: The Limits of Refinement by Severe Plastic Deformation, Adv. Eng. Mater., 2006, 8, 11
[2] P. Parz, M. Faller, R. Pippan, W. Puff, R. Würschum: Microstructure and vacancy-type defects in Al-3wt%Cu after high-pressure torsion, Physics Procedia, accepted