Montag, 09. Juli 2001

Department of Materials Engineering, Technion - Israel Institute of Technology, Haifa ISRAEL

The potential of Atomic Force Microscopy (AFM) in the studies of various aspects of microstructure evolution in metallic systems is demonstrated. The strength of AFM in comparison with the other microscopy techniques is in unique combination of the possibility to scan large surface areas with the atomic resolution along the vertical axis. This is especially helpful in the quantitative analysis of the morphology of grain boundary (GB) grooves forming at the surface of the sample after the high-temperature annealing. The AFM analysis of GB grooves morphology allowed us to study the GB and surface energetics and chemistry in Cu, Fe, the alloys on their basis and in the NiAl intermetallic compounds. We demonstrated how the minor alloying additions, the presence of the liquid phase and the anisotropy of interfaces modify the morphology of GB grooves and their growth kinetics. With the help of GB grooving studies we observed, for the first time, the magnetic effect in the temperature dependence of surface diffusion coefficient in Fe and Fe-Pb alloy. We demonstrated also how the post-mortem AFM measurements of the surface topography help to understand the processes that occurred in the material during high-temperature annealing. The theory of GB grooving in the presence of strong surface anisotropy will be presented. Finally, we emphasize that the high potential of AFM can be realized only in combination with the variety of other available microscopy techniques.

Ort: Wilhelm-Klemm-Str. 10, IG I, HS 2

Zeit: 17 Uhr c.t.

Kolloquiums-Kaffee ab 16.45 Uhr vor dem Hörsaal