Ti-Nb-based Gum Metals exhibit extraordinary superelasticity with ultralow elastic modulus, superior strength and ductility, and a peculiar dislocation-free deformation behavior, most of which challenge existing theories of crystal strength. Additionally, this kind of alloys actually displays even more anomalous mechanical properties, such as the non-linear superelastic behavior, accompanied by...

A recently developed temperature-dependent effective potential method is employed to study the martensitic phase transformation in AuZn. This method is based on ab initio molecular dynamics and allows to obtain finite-temperature lattice vibrational properties. We show that the transversal acoustic TA2[110] mode associated with the phase transition is stabilized at 300 K. Temperature evolution ...

In situ three-dimensional (3-D) X-ray diffraction experiments have been performed at a synchrotron source on low-alloyed multiphase TRIP steels containing 0.25 wt.% Si and 0.44 wt.% Al and produced with different bainitic holding times, in order to assess the influence of the bainitic transformation on the thermal stability of individual austenite grains with respect to their martensitic transf...

In view of the fact that three kinds of phase transformations, i.e. aneutectoid decomposition β→ α+γ2, an ordering transformation β→ β1, and a martensitic transformation β1→ β' have been observed on isothemlal holding and cooling at different rates from the β region in Cu-Al binary alloys, the author has tried to obtain the T/T/T diagrams in order to show the correlations between these three tr...

In this paper we propose a modification of the polycrystalline shape memory alloy constitutive model originally proposed by Souza. By introducing a transformation strain energy with two different hardening coefficients, we are able to take into account the effect of the martensitic transformation of unfavorably oriented grains occurring after the main plateau. By choosing a proper second harden...

Modeling of shape-memory alloys represents a multiscale problem due to occurrence of martensite/austenite phase transformation and a microstructure in the deformation gradient typical for martensitic phase. Inspired by relaxation in static situation, a limit passage between two modeling scales, called microand meso-scales, is performed for the corresponding evolution variants with considering a...

Due to recent concern about allergic and toxic effects of Ni ions released from TiNi alloy into human body, much attention has been focused on the development of new Ni-free, metastable beta-type biomedical titanium alloys with a reversible phase transformation between the beta phase and the alpha'' martensite. This study investigates the effect of the stress-induced alpha'' martensite on the m...

In this paper, we present a thorough stress analysis of the Cu-Zr metallic-glass composite with embedded B2 particles subject to a martensitic transformation. Within the framework of the Eshelby theory, we are able to explain, in a quantitative manner, (1) the formation of three types of shear bands with distinct morphologies as observed experimentally in the severely deformed Cu-Zr metallic-gl...

Martensitic transformation plays a pivotal role in the microstructural evolution and plasticity of many engineering materials. However, so far the underlying atomic processes that accomplish the displacive transformation have been obscured by the difficulty in directly observing key microstructural signatures on atomic scale. To resolve this long-standing problem, here we examine an AISI 304 au...

We propose a simple one-dimensional model which can be used to reconstruct the Peierls-Nabarro energy landscape and compute the limits of lattice trapping for martensitic phase transitions. The model represents a nontrivial analog of the discrete Frenkel-Kontorova model. We find the explicit expression for the critical driving force which sets phase boundaries in motion and delimits the width o...