(Invited) Dealloyed Materials for Corrosion Protection

Abstract

Dealloying has become a wildly popular method to produce complex porous materials with controlled nanostructure. Many types of dealloying are now used, from traditional electrochemical dealloying in which an electrolyte is used for selective etching, to more recent innovations such as liquid metal dealloying where a molten metal is used as a "solvent" and dealloying is driven by enthalpic affinity for one component to dissolve into the molten bath. Historically, dealloying was first intensively studied in the context of corrosion. Dealloying was something to be avoided, not celebrated. Here we turn the question on its head - can we make dealloyed materials that are corrosion-resistant? Toward this end, we report our examinations of studying the corrosion response of two-phase NiTi/Cr films made on engineering alloys by a kind of liquid metal dealloying. These materials exhibit interesting responses associated with their complex two-phase nanostructure formed during the dealloying reaction.