| Owing to the small length scale and high surface-to-volume ratio, one-dimensional nanomaterials behave qualitatively different in mechanical behavior as compared with bulk materials. To predict nanostructure properties and reveal their deformation mechanisms, a large number of computational simulations have been performed. However, due to the small size of nanomaterials and the difficulty of sample mounting, it is still quite challenging to conduct good mechanical testing and validate computational predictions.;Using the unique Nanofactory platforms, in-situ mechanical tests combined with in-situ high resolution TEM observations have been performed successfully on one-dimensional nanomaterials such as silver (Ag) nanowries, silica (SiO 2) nanowires, nanoscale Al90Fe5Ce5 metallic glass and sodium chloride (NaCl) nanowires. 19.3% strain was achieved in the bicystalline Ag nanowires. Stacking faults formed on the (111) plane and interestingly, the stacking fault (local hcp structure) was not induced by partial dislocations movement, but by the Frank loops formation and expansion.;SiO2 glass at room temperature is usually brittle due to fracture instability. However, showered by electron beam, silica nanowires with big diameters (>100 nm) can flow superplastically more than 670%. But once beam is blanked more than 2 minutes, the mechanical response can recover back to brittle failure if silica nanowire’s diameter is large than 20 nm. However, unrecovered beam damage will trigger the brittle to ductile transition if silica nanowire’s diameter is less than 20 nm.;Al90Fe5Ce5 metallic glass with size less than 20 nm can be extremely elongated to ∼200%. Necking occurred without shear bands in the nanoscale sample with an area reduction nearly 100%. Remarkably, even an atomic chain was formed, which was never observed in metallic glasses. The extraordinary ductility in nanosized glass may originate from the fast surface atom diffusion and the absence of shear band formation.;The mechanical test on common salt shows Superplastic nanowires can be formed by touching the NaCl(100) surface with a Au tip in a transmission electron microscope. The nanowires were stretched to 280%, and bent >90° upon compression, when showered with the electron beam. More surprisingly, no dislocations were observable during the elongation due to fast diffusion. |
