Monolayer Generates Reversible Change

摘要

The strength and toughness of a metal or alloy can be strongly affected by surface layers that may alter the corrosion resistance, the ability of dislocations to migrate, or the formation of notches that may lead to larger cracks. Jin and Weissmiiller (p. 1179; see the Perspective by Sieradzki) explore the effect of a monolayer of oxygen species on the surface of nanoporous gold on the plastic yield strength and subsequent flow strength. Nanoporous gold was filled with an electrolyte that only weakly absorbed onto its surface. Applying a small electrical potential changed the absorption and desorption of oxygen at the gold surface, allowing reversible change of the breaking strength, the stress required to initiate plastic deformation, and the amount of plastic deformation the material will tolerate.