title: Improving the ductility of nanocrystalline bcc metals.
abstract: Nanocrystalline metals present extremely high yield strengths but limited ductility. Using atomistic simulations, we show that the fracture resistance of bcc nanocrystalline materials increases with decreasing grain size below a critical grain size. There appears to be a "most brittle" grain size corresponding to the "strongest size" that has been postulated. Impurities that strengthen the grain boundaries can improve ductility significantly for the relatively larger grain sizes, whereas ductility decreases for the smallest grain sizes.
authors.affiliation: Department of Materials Science and Engineering, Virginia Tech, Blacksburg, VA 24061-0237, USA. Diana@vt.edu
authors.forename: Diana
authors.initials: D
authors.lastname: Farkas
authors.forename: Brian
authors.initials: B
authors.lastname: Hyde
mesh_terms: D003198:Computer Simulation; D004548:Elasticity; D006244:Hardness; D008670:Metals / Q000737:chemistry*; D008956:Models, Chemical; D008958:Models, Molecular; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D036103:Nanotechnology / Q000379:methods*; D010316:Particle Size
chemical_list: D008670:Metals