Modulating heterogeneity and plasticity in bulk metallic glasses: Role of interfaces on shear banding. (August 2019)

• Record Type: Journal Article
• Authors: Kosiba, K.; Şopu, D.; Scudino, S.; Zhang, L.; Bednarcik, J.; Pauly, S.
• Is Part Of: International journal of plasticity. Volume 119(2019:Aug.)
• Page Start: 156
• Page End: 170
• Publication Date: 2019-08
• Subjects: Plasticity -- Periodicals; Plasticité -- Périodiques; Plasticity; Periodicals; 620.11233
• DOI: 10.1016/j.ijplas.2019.03.007
• Languages: English
• ISSNs: 0749-6419

Abstract

Abstract : Structural heterogeneities in monolithic metallic glasses, i.e. free volume variations or stress/strain fields, are known to be pivotal for their plasticity but the mechanisms how they affect irreversible deformation remain poorly understood. We show that flash-annealing is a capable tool for modifying the free volume content and its distribution, which creates non-affine stress fields in a monolithic CuZr-based bulk metallic glass. Rather than the overall free volume, μm-scale regions of relaxed and rejuvenated glass govern plastic deformation. Complementary molecular dynamics simulations underpin the importance of the interfaces between relaxed and rejuvenated volumes for shear band proliferation. Not only can we reach unmatched states of metastability in metallic glasses with the present approach but also better understand the mechanisms underlying plasticity in monolithic but structurally heterogeneous metallic glasses. Highlights: Flash-annealing is applied to create a structurally heterogeneous bulk metallic glass. In heterogeneous monolithic bulk metallic glasses shear band formation is promoted. MD simulations reveal that the interfaces between the relaxed and rejuvenated glass retard shear localization. A model is suggested how a nascent shear band interacts with the interfaces between relaxed and rejuvenated regions. Rather than the overall free volume content, its distribution governs the plastic deformability of bulk metallic glasses.