Publication Date:
2015-08-21
Description:
Nature Materials 14, 894 (2015). doi:10.1038/nmat4335 Authors: Shaofeng Sun, Xiying Chen, Nilesh Badwe & Karl Sieradzki 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.
Print ISSN:
1476-1122
Electronic ISSN:
1476-4660
Topics:
Chemistry and Pharmacology
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Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
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Natural Sciences in General
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Physics
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