Defect structures in CuZr martensite are studied by conventional and high-resolution transmission electron microscopy. Two different types of planar defects are observed. It is concluded that both defect types can be inherited from anti-phase boundaries in the austenite phase. With respect to the martensitic transformation, both defect types can be explained by the different shuffles of atoms a...

an artificial neural network (ann) model is developed for the analysis, simulation, and prediction of the austenite reversion in the thermo-mechanical treatment of 304l austenitic stainless steel. the results of the ann model are in good agreement with the experimental data. the model is used to predict an appropriate annealing condition for austenite reversion through the martensite to austeni...

In this study, the effects of Zr addition on phase transformation temperatures, microstructure Ti-12V-4Al (wt. %) high temperature shape memory alloys (HTSMAs) manufactured using melt-spinning technique were investigated. During heating, differential scanning calorimetry (DSC) curves showed that austenite melt-spun ribbon was single-stage and Ti-12V-4Al-0.5Zr two-stage transformation. electron ...

Mechanical devices are sought to support insufficient or paralysed striated muscles including the failing heart. Nickel-titanium alloys (nitinol) present the following two properties: (i) super-elasticity, and (ii) the potential to assume different crystal structures depending on temperature and/or stress. Starting from the martensite state nitinol is able to resume the austenite form (state of...

Plastic pre-strains were applied to the metastable 304L austenitic stainless steel at both room temperature (20 °C) and higher temperatures (i.e., 50, 80 and 100 °C), and then the hydrogen embrittlement (HE) susceptibility of the steel was evaluated by cathodically hydrogen-charging and tensile testing. The 20 °C pre-strain greatly strengthened the steel, but simultaneously significantly increa...

For Fe-Mn-Si-Cr-Ni shape memory alloys, it was previously found by HREM study that the formation of the nanometric lamella structures consisting of f.c.c. and h.c.p. phase is very important to exhibit good shape memory effect. In the present work, the formation process of such lamella structures has been studied in detail. The results are as follows. The transformation is initiated by random fo...

The hysteresis loop, described during the formation of stressinduced pseudoelastic martensite in a Cu-Zn-A1 betaphase single crystal, was studied as a function of strain-rate, deformation amplitude and temperature. The aPtm, the stress at which the transformation starts at a given constant temperature, is strain-rate independent but the hysteresis described by the stress-strain curve shows a ma...

Purpose: The aim of the paper is to design heat treatment conditions of dual-phase steel and to determine their influence on the structure and mechanical properties of steel. Design/methodology/approach: The heat treatment of the C-Mn steel in order to obtain a dual-phase ferritic – martensitic structure of desirable phase fractions was realized. To investigate the influence of heat treatment p...

The crystallography of B2 to R-phase and the subsequent R-phase to B19′ martensite transitions was analysed in NiTi alloys. Using the energy minimization theory of martensitic transformations, the habit plane and twin plane normals were established for the R-phase, B19′ martensite variants as a function of rhombohedral angle . Two types of twins, classified as {1 0 0}〈0 1 1〉 and {1 1 0}〈0 0 1〉 ...