论文部分内容阅读
Metallic glasses (MGs) are attractive for small-scale technological applications due to their attractive mechanical and magnetic properties, and the advantages in net-shape thermoplastic molding.However, the brittleness of MGs has severely impeded their applications.Nanoglasses are amorphous solids consisting of subl0-nanometer-sized glassy "grains" connected by glass/glass interfaces(GGI), in which the free volume is significantly higher than in the grain interior.Here, the mechanical properties of a Sc75Fe25 nanoglass were contrasted with those of monolithic glass with identical chemical composition, using quantitative in-situ tensile and compressive tests inside a transmission electron microscope.The submicron sized samples of nanoglass exhibited considerably larger ductility than monolithic glass, with plastic strain of at least 15% in tension and up to 30% in compression.Such a nearly uniform tensile plasticity is unprecedented among metallic glasses of similar sample sizes, which can be explained by the bimodal distribution of free volume in the glassy grain and GGI.A small subset of the soft glass/glass interfaces (GGI) with maximum Schmid factor initiate plastic flow, but these initial flow defects are impeded by the harder grain interiors at the end of the interface, limiting their mean free paths and catastrophic strain softening.The enhanced ductility of nanoglass opens new avenues of application of metallic glasses at micro-and nano-scales.