Statistical nature of the incipient plasticity in amorphous alloys
| Autor: | Jae-il Jang, C. Mukhopadhyay, Shankha Nag, Upadrasta Ramamurty, R. L. Narayan |
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| Přispěvatelé: | School of Mechanical and Aerospace Engineering |
| Předmět: |
plastic deformation
Materials science nanoindentation nucleation Nucleation Thermodynamics 02 engineering and technology Plasticity 01 natural sciences Metallic Glass Stress (mechanics) metallic glass 0103 physical sciences General Materials Science Weibull distribution 010302 applied physics Plastic Deformation Amorphous metal model Mechanical Engineering Metals and Alloys temperature bimodal distribution shear transformation zone dependence 021001 nanoscience & nanotechnology Condensed Matter Physics Critical value sensitivity Bimodality bulk metallic-glass indentation Mechanics of Materials statistics fracture Mechanical engineering [Engineering] 0210 nano-technology strength Shear band |
| Popis: | 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 Ri 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. Agency for Science, Technology and Research (A*STAR) This work at NTU was conducted under the Structural Metals and Alloys Programme, which was funded by A*STAR, Singapore. The work at Hanyang University was supported by the National Research Foundation of Korea (NRF) grants funded by the Korea government (MSIT) (No. 2020R1A2B5B01001446 andNo. 2020R1A5A6017701). |
| Databáze: | OpenAIRE |
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