The shape memory effect (SMA) relies on martensitic transformations which are macroscopically due to a pseudo-shearing deformation, resulting from a deformation mode similar to slip or twinning in ordinary metals and alloys under stress. However, since martensitic thermoelastic transformations are reversible, the deformation behaviour of alloys that undergo this type of transformations is remar...

In this study, the effect of tensile test temperature (148 to 673 K) on the microstructural evolutions and the mechanical properties of high manganese twinning induced plasticity (TWIP) steel with the chemical composition of Fe- 31Mn-3Al-3Si (wt. %) was investigated. XRD, SEM and TEM were used to study the microstructural evolutions. Stacking fault energy (SFE) of the alloy was also calculated ...

An in-situ characterization technique combining mechanical testing inside a scanning electron microscope (SEM) with electron backscatter diffraction (EBSD) analysis was employed to study the tensile deformation behavior of Nd-containing Mg alloys over the temperature range of 50-250°C. EBSD data were collected before and after the experiments. The active slip and twinning systems were identifi ...

The Bauschinger effect (BE) in single crystals of Hadfield manganese steel (Fe, 12.3Mn, 1.0C in wt pct) was studied for three crystallographic orientations, [111], [123], and [001]. Both forward tensionreverse compression (FT/RC) and forward compression-reverse tension (FC/RT) loading schemes were used to investigate the role of deformation history on the BE. The evolution of stress-strain resp...

Displacive deformation via dislocation slip and deformation twinning usually plays a dominant role in the plasticity of crystalline solids at room temperature. Here we report in situ quantitative transmission electron microscope deformation tests of single crystal Sn samples. We found that when the sample size was reduced from 450 nm down to 130 nm, diffusional deformation replaces displacive p...

Coarse-grained limestone samples were collected across the Hudson Valley Fold-Thrust Belt with the aim of determining the temporal and spatial relationship between calcite twinning strain and fold-thrust belt development. The majority of the samples have well defined oblate strain ellipsoids with the maximum shortening axes (e3) perpendicular to bedding strike, and e3 magnitudes that range from...

In this study, a Lüders-type deformation with ∼40% strain of B19' martensite phase was observed in Ni47Ti49Nb2Fe2 alloy at −50 °C. Such phenomenon attributed to the nearly equal critical stresses both dislocation slip and twinning, which result two mechanisms co-operate concurrently. The large-strain disappeared when temperature away from This probably due different dependence twinning. Owing h...