Regensburg 2007 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 38: Diffusion and point defects III
MM 38.4: Vortrag
Donnerstag, 29. März 2007, 15:30–15:45, H6
Element specific defect investigation on Mg-alloys by ion implantation with coincident Doppler broadening spectroscopy — •Martin Stadlbauer1, Christoph Hugenschmidt2, and Klaus Schreckenbach1 — 1TU Munich, ZWE FRM-II, Garching, Germany — 2TU Munich, Department of Physics E21, Garching, Germany
Magnesium alloys experience an increasing interest for industrial applications due to their low specific weight, high elasticity and mechanical strength. For the high performance of these materials a homogeneous distribution of the alloy constituents is required. It is therefore of great interest to investigate the behaviour of the alloy constituents in the vicinity of open volume defects.
In order to investigate the influence of defects and their chemical surrounding, polished and annealed samples of pure magnesium and the alloy AZ31 (3 wt. % Al and 1 wt. % Zn) were irradiated with Zn-, Al- and Mg-ions. The energy of the ions was chosen between 1.4 MeV and 3.0 MeV according to 2.3 µ m mean implantation depth. For every type of material a set of 4 samples was produced with doses between 3 · 1013 and 3 · 1016 cm−2. First, Doppler-Broadening measurements as a function of the positron implantation energy as well as lateral position with a resolution of 2 mm were recorded in order to image the ion beam spot on the sample. Secondly, coincident Doppler-broadening spectra were measured at different positron penetration depths according to the Makhov-profile. The relation between elemental signature and defect concentration in the sample are discussed.