Size effects in the deformation of sub-micron Au columns

摘要: Uniaxial compression tests have been performed on single crystal Au columns ranging in diameter from 180 nm to 8 µm. The were machined into the surface of a large-grained sheet using focused ion beam microscope and then mechanically tested nanoindenter outfitted with flat diamond punch. Images compressed show that deformation occurs by localized shear slip systems largest resolved stresses. After an elastic loading regime, exhibit yielding discrete strain bursts. compressive yield stress scales roughly as inverse square root column diameter. apparent hardening rate also increases strongly decreasing stresses large 1 GPa are reached. Both these size effects attributed dislocation source-limited behaviour small volumes.