Hi Friends
I want to share some of our recent research work on the stress induced phase transformation of CuZr nanowire which is published in Materials Letters.
http://dx.doi.org/10.1016/j.matlet.2009.02.064
In this work a novel stress-induced martensitic phase transformation in an initial <100>/{100} B2-CuZr nanowire is reported for the first time in this letter. Such behavior is observed in a nanowire with cross-sectional dimensions of 19.44 x 19.44 Å2 over a temperature range of 100-400 K and at a strain rate of 1x109 s- 1 using atomistic simulations. Phase transformation from an initial B2 phase to a BCT (Body-Centered-Tetragonal) phase is observed via nucleation and propagation of {100} twinning plane under high strain rate tensile deformation.
Cu–Zr nanowires stress-induced martensit
Following the above paper titled as " Stress induced martenistic phase transformation in Cu-Zr nanowires" published in Materials Letters, Volume 63, Issue 15, 15 June 2009, Pages 1289-1292 by Vijay Kumar Sutrakar and D. Roy Mahapatra; a very recent paper titled as "Pseudoelasticity of Cu–Zr nanowires via stress-induced martensitic phase transformations" is published in Appl. Phys. Lett. 95, 021911 (2009); doi:10.1063/1.3183584 by Q. Cheng, H A Wu, Y Wang and XX Wang.
The abstract of the paper is as follows:
Atomistic simulations were performed to investigate the pseudoelastic effects induced by martensitic phase transformation from body-centered cubic (B2) to body-centered tetragonal (BCT) lattice in Cu–Zr nanowires. The phase transformation occurs through nucleation and propagation of {100} twin boundary, which differs from the {101} twin boundary for B2 Ni–Al nanowires. During unloading, extension strain up to 45% can be fully recovered through inverse phase transformation. The BCT lattice has also been verified to be metastable for Cu–Zr nanowires with an energy analysis along the epitaxial Bain path. Our work implies Cu–Zr nanowires may be excellent functional components for nanoelectromechanical systems. ©2009 American Institute of Physics
comment on pseudoelasticity of cu-zr nanowire
Single and multi-step phase transformation in CuZr nanowire
Recently, a paper titled "Single and multi-step phase transformation in CuZr nanowire under compressive/tensile loading" is published in Intermetallics by Vijay Kumar Sutrakar and D Roy Mahapatra . The abstract of the paper is given below. Full paper can be downloaded from doi:10.1016/j.intermet.2009.11.006
Abstract:
A novel stress induced martenistic phase transformation is reported in an initial B2-CuZr nanowire of cross-sectional dimensions in the range of 19.44 × 19.44–38.88 × 38.88 Å2 and temperature in the range of 10–400 K under both tensile and compressive loading. Extensive Molecular Dynamic simulations are performed using an inter-atomic potential of type Finnis and Sinclair. The nanowire shows a phase transformation from an initial B2 phase to BCT (body-centered-tetragonal) phase with failure strain of 40% in tension, whereas in compression, comparatively a small B2 → BCT phase transformation is observed with failure strain of 25%. Size and temperature dependent deformation mechanisms which control ultimately the B2 → BCT phase transformation are found to be completely different for tensile and compressive loadings. Under tensile loading, small cross-sectional nanowire shows a single step phase transformation, i.e. B2 → BCT via twinning along {100} plane, whereas nanowires with larger cross-sectional area show a two step phase transformation, i.e. B2 → R phase → BCT along with intermediate hardening. In the first step, nanowire shows phase transformation from B2 → R phase via twinning along {100} plane, afterwards the nanowire deforms via twinning along {110} plane which cause further transformation from R phase → BCT phase. Under compressive loading, the nanowire shows crushing along {100} plane after a single step phase transformation from B2 → BCT. Proper tailoring of such size and temperature dependent phase transformation can be useful in designing nanowire for high strength applications with corrosion and fatigue resistance.