Buch, Englisch, Band 13, 289 Seiten, PB, Format (B × H): 148 mm x 210 mm, Gewicht: 434 g
Reihe: Saarbrücker Reihe Materialwissenschaft und Werkstofftechnik
Buch, Englisch, Band 13, 289 Seiten, PB, Format (B × H): 148 mm x 210 mm, Gewicht: 434 g
Reihe: Saarbrücker Reihe Materialwissenschaft und Werkstofftechnik
ISBN: 978-3-8322-7834-2
Verlag: Shaker
The fine scale mechanical probing capability of NI-AFM was used to examine hydrogen interaction with plasticity. To realize this, an electrochemical three electrode setup was incorporated into the NI-AFM. The developed ECNI-AFM is capable of performing nanoindentation as well as imaging surfaces inside electrolytes.
The developed ECNI-AFM setup was used to examine the effect of cathodically charged hydrogen on dislocation nucleation in pure metals and alloys. It was shown that hydrogen reduces the pop-in load in all of the tested materials except Cu. The reduced pop-in load can be interpreted as the HELP mechanism. Classical dislocation theory was used to model the homogeneous dislocation nucleation and it was shown that H reduces the activation energy for dislocation nucleation in H sensitive metals which are not undergoing a phase transformation. The activation energy for dislocation nucleation is related to the material specific parameters; shear modulus µ, dislocation core radius ? and in the case of partial dislocation nucleation, stacking fault energy ?. These material properties can be influenced by H resulting in a reduced activation energy for dislocation nucleation.
