Regensburg 2013 – scientific programme
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MM: Fachverband Metall- und Materialphysik
MM 48: Invited Talk (Hauptvortrag): Barnoush
MM 48.1: Invited Talk
Thursday, March 14, 2013, 09:30–10:00, H24
Hydrogen embrittlement revisited by novel nano-mechanical approach — •Afrooz Barnoush1,2, Mohammad Zamanzade2, Masoud Asgari1, Roy Johnsen1, and Horst Vehoff2 — 1Norwegian university of science and technology, Trondheim, Norway — 2Saarland university, Saarbruecken, Germany
Despite hydrogen embrittlement is known for more than a century a clear explanation of the governing mechanism is still missing. This is mainly due to the complexities of the experimental examination of hydrogen embrittlement. On the basis of these complexities a novel experimental approach, in situ electrochemical nanoindentation (ECNI), is developed. ECNI is capable of registering the onset of plasticity in extremely small volumes which can consider as perfect crystals in hydrogen free and charged conditions. It is shown that hydrogen reduces the required stress for the onset of plasticity due to reduction in the dislocation line energy. This reduction in dislocation line is explained by the Defactant Concept, i.e. reduction of the defect formation energy in the presence of hydrogen. The extent of the reduction in the dislocation line energy measured during nanoindentation can be successfully used to evaluate the intrinsic resistivity of the examined alloy or metal against hydrogen embrittlement. This makes ECNI a versatile technique for development of new hydrogen resistant alloys or coatings.