The maximum strength of polycrystalline metals/alloys has been suggested to occur at nanoscale grain sizes where the governing deformation mechanism transitions from dislocation plasticity to grain boundary mediated d...The maximum strength of polycrystalline metals/alloys has been suggested to occur at nanoscale grain sizes where the governing deformation mechanism transitions from dislocation plasticity to grain boundary mediated deformation.Despite tremendous progress recently uncovering links between transitions in nanoscale mechanisms and peak strength,the scientific literature is mostly devoid of any quantitative support,owing to the difficulty in measuring the resolved contribution of individual mechanisms to microstructural strain accommodation.In this study,the contribution of individual nanoscale mechanisms to the overall deformation of nanocrystalline Ni is calculated from atomistic simulations leveraging continuum-based kinematic metrics to compute mechanistic contributions to microstructural strain.展开更多
基金Authors G.J.T,G.B.T.,and A.G.are grateful for the support of ARO through grant no.W911NF-17-1-0528greatly acknowledge ARO Program Manager,Dr.Michael Bakas.G.J.T.and A.G.also acknowledge XSEDE allocation charge no.TG-DMR190011hpc resource mio at Colorado School of Mines for allowing the reported atomistic simulations.D.L.M.is grateful for the support of the NSF CMMI-1761553.
文摘The maximum strength of polycrystalline metals/alloys has been suggested to occur at nanoscale grain sizes where the governing deformation mechanism transitions from dislocation plasticity to grain boundary mediated deformation.Despite tremendous progress recently uncovering links between transitions in nanoscale mechanisms and peak strength,the scientific literature is mostly devoid of any quantitative support,owing to the difficulty in measuring the resolved contribution of individual mechanisms to microstructural strain accommodation.In this study,the contribution of individual nanoscale mechanisms to the overall deformation of nanocrystalline Ni is calculated from atomistic simulations leveraging continuum-based kinematic metrics to compute mechanistic contributions to microstructural strain.
