Statistical nature of the incipient plasticity in amorphous alloys. (October 2020)

• Record Type: Journal Article
• Authors: Nag, Shankha; Narayan, R.L.; Jang, Jae-il; Mukhopadhyay, C.; Ramamurty, Upadrasta
• Is Part Of: Scripta materialia. Number 187(2020)
• Page Start: 360
• Page End: 365
• Publication Date: 2020-10
• Subjects: Metallic glass -- Plastic deformation -- Nanoindentation -- Statistics -- Bimodal distribution; Materials -- Periodicals; Metallurgy -- Periodicals; Metalen; Legeringen; Materiaalkunde; Metals, metalworking and machinery industries; Metals; Electronic journals; 620.11
• DOI: 10.1016/j.scriptamat.2020.06.045
• Languages: English
• ISSNs: 1359-6462

Abstract

Abstract: Statistical analyses of the first pop-in stress data, obtained by spherical tip-nanoindentation experiments on different metallic glasses (MGs) with tip radius, Ri, loading rate, P ˙, and structural state of the glass as experimental variables, show that the 3-parameter bimodal Weibull distribution best captures the stochastic nature of the incipient plastic strengths. Significant bimodality in the strength distributions was observed only when a larger R i and P ˙ are employed. We hypothesize that the stress required for shear band nucleation has to exceed a critical value over a characteristic distance over which the stress gradients are minimum to rationalize the bimodality. Graphical abstract: Image, graphical abstract