Deformation of as-fabricated and helium implanted 100 nm-diameter iron nano-pillars
Abstract
〈101〉-oriented cylindrical single crystalline Fe samples with diameters of 100 nm and heights of 1 μm were implanted with 0.36±0.06 at% helium throughout their gauge sections. Uniaxial deformation experiments revealed a 40% higher yield and ultimate strengths in tension and a 25% higher yield strength and flow stress at 10% plastic strain in compression for implanted samples compared with as-fabricated ones. Observed tension–compression asymmetry in implanted pillars was attributed to the non-planarity of screw dislocation cores and to twinning-antitwinning deformation typical of bcc metals and the interaction between dislocations and He bubbles. Compressive stress–strain data in both sets of samples had three distinct regimes: (1) elastic loading followed by (2) discrete strain bursts during plastic flow with significant hardening up to strains of 5%, and (3) "steady state" discrete plasticity characterized by nearly-constant average flow stress. Each regime is discussed and explained in terms of competition in the rates of dislocation multiplication and dislocation annihilation.
Additional Information
© 2014 Elsevier B.V. Received 24 March 2014; Received in revised form 12 June 2014; Accepted 14 June 2014; Available online 20 June 2014. The authors gratefully acknowledge the financial support of the U.S. Department of Energy, Office of Basic Energy Sciences through JRG׳s Early Career grant DE-FOA-00003951. The authors also acknowledge support and infrastructure provided by the Kavli Nanoscience Institute (KNI). Helium implantation was supported by Center for Integrated Nanotechnologies (CINT), a DOE nanoscience center jointly operated by Los Alamos and Sandia National Laboratories.Additional details
- Eprint ID
- 49580
- Resolver ID
- CaltechAUTHORS:20140911-092057079
- Department of Energy (DOE)
- DE-FOA-00003951
- Kavli Nanoscience Institute (KNI)
- Center for Integrated Nanotechnologies (CINT)
- Created
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2014-09-11Created from EPrint's datestamp field
- Updated
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2021-11-10Created from EPrint's last_modified field
- Caltech groups
- Kavli Nanoscience Institute