This content will become publicly available on March 16, 2015
Sink property of metallic glass free surfaces
When heated to a temperature close to glass transition temperature, metallic glasses (MGs) begin to crystallize. Under deformation or particle irradiation, crystallization occurs at even lower temperatures. Hence, phase instability represents an application limit for MGs. Here, we report that MG membranes of a few nanometers thickness exhibit properties different from their bulk MG counterparts. The study uses in situ transmission electron microscopy with concurrent heavy ion irradiation and annealing to observe crystallization behaviors of MGs. For relatively thick membranes, ion irradiations introduce excessive free volumes and thus induce nanocrystal formation at a temperature linearly decreasing with increasing ion fluences. For ultra-thin membranes, however, the critical temperature to initiate crystallization is about 100 K higher than the bulk glass transition temperature. Molecular dynamics simulations indicate that this effect is due to the sink property of the surfaces which can effectively remove excessive free volumes. These findings suggest that nanostructured MGs having a higher surface to volume ratio are expected to have higher crystallization resistance, which could pave new paths for materials applications in harsh environments requiring higher stabilities.
- Texas A & M Univ., College Station, TX (United States). Dept. of Nuclear Engineering, Dept. of Materials Science and Engineering.
- Peking Univ., Beijing (China). School of Physics.
- Texas A & M Univ., College Station, TX (United States). Dept. of Nuclear Engineering.
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
- Tohoku Univ., Sendai (Japan). Inst. for Materials Research.
- Oklahoma State Univ., Stillwater, OK (United States). School of Mechanical and Aerospace Engineering.
- Publication Date:
- OSTI Identifier:
- Grant/Contract Number:
- FE0004007; AC52-06NA25396; AC02-06CH11357
- Accepted Manuscript
- Journal Name:
- Scientific Reports
- Additional Journal Information:
- Journal Volume: 5; Journal Issue: C; Journal ID: ISSN 2045-2322
- Nature Publishing Group
- Research Org:
- Texas A & M Univ., College Station, TX (United States); Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Argonne National Lab. (ANL), Argonne, IL (United States)
- Sponsoring Org:
- National Science Foundation (NSF); USDOE
- Country of Publication:
- United States
- 36 MATERIALS SCIENCE; STRUCTURAL PROPERTIES; METALS AND ALLOYS; 77 NANOSCIENCE AND NANOTECHNOLOGY; metals and alloys; structural properties
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