Iron shows a pressure-induced martensitic phase transformation from the ground state ferromagnetic bcc phase to a nonmagnetic hcp phase at approximately 13 GPa. The exact transformation pressure (TP) and pathway are not known. Here we present a multiscale model containing a quantum-mechanics-based multiwell energy function accounting for the bcc and hcp phases of Fe and a construction of kinema...

Structural characteristics of phase transformations in epitaxial ferroelectric films are analyzed via a Landau–Devonshire thermodynamic formalism. It is shown that the phase transformation temperature, the lattice parameters, and the order of the phase transformation are a strong function of the misfit strain and are considerably different compared to unconstrained, unstressed single crystals o...

A phase-field model is presented to study binary systems having two phases with different elastic properties. The evolution of two phase-field variables, namely, composition and non-conserved phase-field, are considered. This model uses the approach of Steinbach and Apel [1] to model the dependence of total strain on the phase-field, which assumes equal elastic stresses in the different phases ...

The common facets of anatase crystals are the (001) and (101) planes. However, the phase transformation from lepidocrocite-type titanate into anatase by hydrothermal processing yields an anatase microstructure with high concentration of exposed (010) planes. The phase transformation of a lepidocrocite-type protonated layered titanate (HTO) into anatase was studied using XRD, TEM, FTIR, and meas...

Shape memory alloys (SMAs) exhibit two very important properties: shape memory phenomenon and superelastic deformation due to intrinsic thermoelastic martensitic transformation. To fully exploit the potential of SMAs in developing functional structures or smart structures in mechanical and biomechanical engineering, it is important to understand and quantify the failure mechanisms of SMAs. This...

Urban centres in the world are undergoing facets of changes, these changes are evident in developing countries and more divergent because urban transformation in developing countries is often accompanied challenges which include traffic congestion, overcrowding, pollution and continuous land use succession. This phenomenon is not different with the central area of Minna, Nigeria. Since 2008 the...

in the present research, in contrast to the available papers, not only the superelasticity but also the shape memory effects are taken into account in determination of the impact responses. at the same time, in addition to modifying brinson’s model for the shape memory alloys (smas), to include new parameters and loading events, and hertz contact law, distributions of the sma phases are conside...

copper sulphide (cu 2 s) thin films at different thicknesses and annealing temperatures were deposited onto glass substrate by vacuum evaporation method. xrd study reveals the phase transformation of cu     2 s film at higher thickness. optical and resistivity study show the phase transformation of the film from cu     2 s to cus when they are annealed at higher temperature. sem st...

This study investigated the effect of nanograins size on the R-phase transformation of a nanocrystalline Ti-50.2at%Ni alloy. The nanometric grain size was created by severe cold deformation and low temperature anneal. It was found that in the recrystallized state, nanograin sizes (<100 nm) was effective in suppressing the B2→B19’ martensitic transformation and revealing the B2↔R transformation....