Effect of lattice defects on the plastic Poisson's ratio of nanoporous gold. (August 2020)

• Record Type: Journal Article
• Authors: Cao, Luoxia; Zeng, Zhi; Fan, Feifei
• Is Part Of: Scripta materialia. Number 185(2020)
• Page Start: 175
• Page End: 180
• Publication Date: 2020-08
• Subjects: Nanoporous gold -- Plastic Poisson's ratio -- Tension-compression asymmetry -- Molecular dynamics; Materials -- Periodicals; Metallurgy -- Periodicals; Metalen; Legeringen; Materiaalkunde; Metals, metalworking and machinery industries; Metals; Electronic journals; 620.11
• DOI: 10.1016/j.scriptamat.2020.03.046
• Languages: English
• ISSNs: 1359-6462

Abstract

Abstract: Nanoporous gold (np-Au) exhibits variations in the value of the plastic Poisson's ratio, ν p – ranging from negative to positive – often for similar relative densities and ligament diameters. We investigate the effect of pre-existing lattice defects on ν p of np-Au using molecular dynamics simulations. Uniaxial compression of np-Au samples that have the same porous morphology, but distinct defect densities, shows that a high density of pre-existing defects reduces ν p . We interpret this observation by linking nanoscale tension-compression asymmetry in individual ligaments to the synergistic interplay between defects and surfaces, and ultimately to the plastic transverse coupling in np-Au. Graphical abstract: Image, graphical abstract