Chang, H. J. Kim, S. Y. Moon, W. -J. Kim, Y. -M. Park, E. S. Kim, D. H. 2024-01-19T21:32:17Z 2024-01-19T21:32:17Z 2021-09-04 2018-11 0966-9795 https://pubs.kist.re.kr/handle/201004/120756 Structural changes in the vicinity of a crack during ductile fracture in various metallic glasses (MGs) with the propensity of forming shear bands were investigated by in situ straining inside a MeV transmission electron microscope (TEM). During tensile loading, a plastic deformation zone with a width of similar to 100 nm and shear bands with a width of similar to 15 +/- 5 nm developed from crack tips of ductile fracture in MGs. In particular, crack propagation by nanovoid formation and coalescence was observed in Ti40Zr29Cu9Ni8Be14 MG with the highest compressive plasticity (similar to 6.7 +/- 0.5%) among the tested MGs, whereas this process was hardly observable in other MGs. This difference may be attributed to atomic scale heterogeneities in Ti40Zr29Cu9Ni8Be14 4 MG induced by icosahedral short range orders (ISRO), which cause pronounced shear band branching and thus delay fracture process. Meanwhile, no crystallization of MGs even with ISRO or with lower T-x (crystallization onset temperature) was observed during in situ straining inside the MeV TEM and uniaxial tensile test with ribbon samples; a possible effect of normal stress and nanovoid formation during in situ straining is discussed to compare with crystallization during uniaxial compression test of the same MGs. Our study provides an insight into intrinsic toughening of MGs and thus can give useful guidelines on how to delay ductile fracture processes of MGs by tuning nanovoid formation, taking advantage of structural features through-eustomized desigh of MGs. English ELSEVIER SCI LTD TENSILE FRACTURE SHEAR BANDS NANOCRYSTALS Probing structural changes during ductile fracture in metallic glasses via in situ straining inside a MeV transmission electron microscope Article 10.1016/j.intermet.2018.08.012 1 INTERMETALLICS, v.102, pp.94 - 100 INTERMETALLICS 102 94 100 scie scopus 000447581400013 2-s2.0-85053076014 Chemistry, Physical Materials Science, Multidisciplinary Metallurgy & Metallurgical Engineering Chemistry Materials Science Metallurgy & Metallurgical Engineering Article TENSILE FRACTURE SHEAR BANDS NANOCRYSTALS Metallic glass In situ straining Ductile fracture Shear hand Intrinsic toughening Transmission electron microscope