Abstract Scope |
Vacancy clusters have a major implication on multiple mechanisms (oxidation, precipitation, creep). It is thus essential to have a deep understanding of these defect stability. Multiple factors influence their formation, yet the preponderant factor seems to be the presence of a gaseous environment, like H.
For this purpose, we investigate at the atomic-scale the formation of such clusters. Using empirical force fields (EAM), we show that the interaction between point-defects is attractive which favors the cluster formation. We determine their stable shape for various fcc metals: Al, Pd, Ni, Cu, Au, Ag. Finally, we show that H not only drastically decreases the formation energy and influences their stable shape but also influences the long-range elastic distortion arising to the vacancy clusters. Hence that have a direct consequence on the interaction between the clusters with dislocations and the other material defects and those impact the mechanical properties (elastic and plastic behavior). |