The high-cycle, push-pull fatigue fracture behavior of high-C, Si-Al-rich nanostructured bainitic steel was studied through the measurement of fatigue limits, a morphology examination and phase composition analysis of the fatigue fracture surface, as well as fractography of the fatigue crack propagation. The results demonstrated that the push-pull fatigue limits at 10⁷ cycles were estimated as ...

Two Way Shape Memory Effect (TWSME) involves thermomechanical routines which produce some plastic deformation or complex dislocation arrays during the training procedure. The results of TWSME obtained by these thermomechanical training routines are not as good as would be expected because new dislocations are generated during thermal cycling. These dislocations may interact with those that prov...

The stability of austenite against strain induced martensitic transformation (SIMT) strongly depends on the grain size of the austenite. This is observed in austenitic steels with grain sizes from several pm up to several hundred pm and for much smaller austenitic grains (three orders of magnitude) that are embedded in a non austenitic matrix. fcc Fe-precipitates may be formed in dilute Cu-Fe a...

For the mechanical behavior of steels with metastable austenite, it was widely accepted that high strain rates could weaken deformation-induced martensitic transformation (DIMT) and reduce work-hardening behavior. This limits application these for energy-absorption applications, e.g., impact conditions. However, mechanism strain-rate dependent DIMT is still not well understood greatly limited f...

The structural changes occurring during tempering of Fe-N martensite (a') have been investigated using X-ray diffraction and (high resolution) transmission electron microscopy. The first stage of decomposition of Fe-N martensite leads to the formation of &-nitride and ferrite (a). The formation of a"-nitride involves both a local enrichment and ordering of N atoms; the Fe sublattice remains of ...

Freestanding nanowires have been found to exhibit ultra-large elastic strains (4 to 7%) and ultra-high strengths, but exploiting their intrinsic superior mechanical properties in bulk forms has proven to be difficult. A recent study has demonstrated that ultra-large elastic strains of ~6% can be achieved in Nb nanowires embedded in a NiTi matrix, on the principle of lattice strain matching. To ...

The purpose of this study was to evaluate the effect of heat treatment on the transformation temperatures of K3, K3XF and MTwo endodontic files. DSC was used to investigate the domains of transformation temperatures and how the transformation temperatures vary along the file. The files were analysed as received and subjected to heat treatment. X-ray diffraction analysis was also used to investi...

Two stage austenite ??-martensite ??-martensite phase transformation, phase-specific lattice strain evolution and load sharing during tensile deformation of a 13%Mn hot-rolled austenitic steel are revealed by in-situ neutron diffraction. Direct evidence is provided that serrated behavior attributed to discontinuous martensitic transformation.

The fatigue behavior of the two austenitic stainless steels AISI 904L and 347 with different surface morphologies, (i) conventionally turned finally polished, (ii) cryogenic using CO2 snow, as well (iii) was investigated an ultrasonic testing system up to very high cycle regime system. is stable against deformation-induced phase formation while in metastable state shows martensite induced by tu...