Regensburg 2007 – scientific programme

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MM: Fachverband Metall- und Materialphysik

MM 2: SYM Micro- and Nanomechanics I

MM 2.1: Invited Talk

Monday, March 26, 2007, 10:15–10:45, H16

Effect of hydrogen and grain boundaries on dislocation nucleation and multiplication examined with a Ni-AFM — •Horst Vehoff and Afrooz Barnoush — Institut für Werkstoffwissenschaft, Universität des Saarlandes, 66041 Saarbrücken

A nanoindenting AFM with an environment chamber was constructed to study the effect of hydrogen on decohesion and dislocation nucleation and the effect of grain boundaries on dislocation nucleation. Ultra fine grained Ni and Ni single crystals were examined. It could be clearly shown that hydrogen influences the pop in width and length. Testing single grains with grain sizes below one micron at different rates inside a Ni-AFM showed that the rate dependence of UFG Ni is a result of the interaction of the growing dislocation loop with the boundary. The results will be discussed in the talk.