title: Potential-dependent dynamic fracture of nanoporous gold.
abstract: When metallic alloys are exposed to a corrosive environment, porous nanoscale morphologies spontaneously form that can adversely affect the mechanical integrity of engineered structures. This form of stress-corrosion cracking is responsible for the well-known 'season cracking' of brass and stainless steel components in nuclear power generating stations. One explanation for this is that a high-speed crack is nucleated within the porous layer, which subsequently injects into non-porous parent-phase material. We study the static and dynamic fracture properties of free-standing monolithic nanoporous gold as a function electrochemical potential using high-speed photography and digital image correlation. The experiments reveal that at electrochemical potentials typical of porosity formation these structures are capable of supporting dislocation-mediated plastic fracture at crack velocities of 200 m s(-1). Our results identify the important role of high-speed fracture in stress-corrosion cracking and are directly applicable to the behaviour of monolithic dealloyed materials at present being considered for a variety of applications.
authors.affiliation: Ira A. Fulton School of Engineering, Arizona State University, Tempe, Arizona 85281, USA.
authors.forename: Shaofeng
authors.initials: S
authors.lastname: Sun
authors.affiliation: Ira A. Fulton School of Engineering, Arizona State University, Tempe, Arizona 85281, USA.
authors.forename: Xiying
authors.initials: X
authors.lastname: Chen
authors.affiliation: Ira A. Fulton School of Engineering, Arizona State University, Tempe, Arizona 85281, USA.
authors.forename: Nilesh
authors.initials: N
authors.lastname: Badwe
authors.affiliation: Ira A. Fulton School of Engineering, Arizona State University, Tempe, Arizona 85281, USA.
authors.forename: Karl
authors.initials: K
authors.lastname: Sieradzki