Regensburg 2013 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 41: Mechanical Properties II
MM 41.2: Vortrag
Mittwoch, 13. März 2013, 15:15–15:30, H26
Influence of hydrogen on the defect structure in metals subjected to plastic deformation — •Martin Deutges1, Inga Knorr1, Hans Peter Barth1, Yuzeng Chen2, Christine Borchers1, Cynthia Volkert1, and Reiner Kirchheim1,3 — 1Institut für Materialphysik, Georg-August Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany — 2State Key Lab of Solidification Processing, Northwestern Polytechinical Univeristy, Xi’an, China — 3International Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu University, Japan
The interaction between dissolved atoms and crystal defects can be studied on specific model systems.
Hydrogen enhances the formation and the mobility of dislocations. This can be demonstrated by palladium which is cold rolled with and without hydrogen content. The presence of hydrogen markedly increases the dislocation density. TEM investigations show that the arrangement of dislocations changes with hydrogen concentration.
Another experiment is the deformation of vanadium micropillars. At low hydrogen concentrations, the pillars deform on a few discrete slip planes generating serrations, and at higher concentrations the pillars deform to a barrel-like shape.
These experiments can be analyzed using the defactants concept. The basis of the defactants concept is the assumption that a decrease of the overall free energy by the segregation of solute atoms to a defect can be ascribed to a decrease in the defect formation energy.