The phase-field method has recently been extended and utilized across many fields in materials science. Since this method can systematically incorporate the effect of coherent strain induced by lattice mismatch and applied stress as well as external electric and magnetic fields, it has been applied to many material processes including solidification, solid-state phase transformations and various types of complex microstructure changes.
   In this paper, firstly the calculation method of phase-field approach is briefly explained. In particular, the basic philosophy of phase-field simulation is mentioned. Secondly, we summarize the recent calculation results of the phase-field simulation of phase transformations in Fe-based alloys and Ni (or Co)-based superalloys. Finally, the image-based calculation of materials properties is explained, where the simulated microstructure image that is the output data of phase-field simulation is employed as a boundary condition for calculating the materials property, and we show the cases of the mechanical property (stress-strain curve), magnetic property (ferromagnetic hysteresis) and electric property (ferroelectric hysteresis) as typical examples of this approach.

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  It has been believed that preferentially oriented growth of Al scarcely occurs on Si substrates in an ordinary high vacuum (10^-3 Pa). In order to examine the effect of rapid deposition on the epitaxial growth, we try the evaporation of Al from dual sources of W baskets onto Si (100) and (111) substrates which are heated in an ordinary high vacuum. From the inspection of the Al films 100 to 200 nm in thickness by transmission electron microscopy, it is found that double-positioned {110} grains and (111) ones grow preferentially on the (100) and (111) substrates, respectively, heated at about 600 K.

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  Oxidation resistance of electroplated Pt and Pt-Ir alloy coatings followed by simple annealing heat treatments was investigated. The so-called 2nd generation Ni-based single crystal superalloy TMS-82+ and 4th generation TMS-138 were used as substrate materials. The cyclic oxidation tests and corresponding surface observations suggested the comparable oxidation resistance of Pt-coated TMS-82+ and Pt-Ir-coated TMS-138. However, cross-sectional microstructural analysis revealed that Pt-coated TMS-82+ exhibited the accelerated formation of voids, indicating the beneficial effect of Ir addition in terms of suppressed void formation. This study also revealed the importance of cross sectional analysis for thoroughly evaluating specimens subjected to the cyclic oxidation tests, and confirmed that oxidation resistance of the electroplated coatings was dependent on the quality of films deposited, which was drastically affected by the substrate surface finishing and substrate composition.

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  Zr₇₀Ni₁₆Cu₆Al₈ bulk metallic glass (BMG) exhibited clear tensile plastic deformation at room temperature. The tensile plastic deformation was induced by the specimen sliding along one main shear band, which completely penetrated the specimen. Also, it was surmised that there is a viscous medium in a main shear band. Therefore, it can be considered that the viscous medium in the shear band plays an important role in the mechanical properties of the BMG under tensile loading. In this study, tensile tests of the Zr₇₀Ni₁₆Cu₆Al₈ BMG were carried out at the temperatures of 293 and 133 K to investigate the effect of the viscous medium in the shear band on the mechanical properties of the BMG. As the results, it was found that the strength of the BMG at 133 K was 21% higher than that at 293 K. Furthermore, at 133 K, highly denser, longer, and many branching and curving shear bands were observed over a wide area of the specimen surface in comparison with those at 293 K. In addition, at 133 K, a few main shear bands were observed on the fracture surface.

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  A sliding wear test was conducted on a copper single crystal having (001) surface. In the vicinity of worn surface, equiaxed fine grains that were separated by high-angle boundaries were generated. On the other hand, formations of low-angle boundaries were predominant at the area distant from the worn surface. In the present study, the formation of low-angle boundaries that were perpendicular to the worn surface and evolution of the high-angle boundaries were investigated by the electron backscatter diffraction (EBSD) method. In the region where the low-angle boundaries were formed predominantly, lattice rotation occurred almost around the axis which is normal to the wear direction. However, from a detailed orientation analysis, local rotation axes were slightly different even in the same grain. The perpendicular low-angle boundaries could be introduced by a misorientation between adjoining areas that had such different rotation axes. Amount of the high-angle boundaries increased with decreasing depth from the worn surface. At the vicinity of the worn surface, many coincidence-site lattice (CSL) boundaries with various Σ-values were recognized. On the other hand, near the low-angle boundary region, the CSL boundaries were limited to Σ13a and Σ25a. This characteristic distribution of Σ-value could be understood from a model that the high-angle boundaries were generated by accumulated lattice rotation induced by the sliding wear.

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  Crack nucleation along deformation twin boundary has been investigated in an Fe-20%Cr alloy. The deformation twins were introduced by compression test in liquid nitrogen. Push-pull fatigue tests on the twinned specimens were carried out at room temperature. Two kinds of cracks were detected in the vicinity of the twin boundaries: one was a serrated intragranular crack and the other was an intergranular crack formed along the twin boundary. From a monotonic tensile test on a twinned specimen, it is confirmed that the serrated crack was generated as a result of twin boundary migration during detwinning process, regardless of fatigue cycling. After the fatigue loading was sufficiently repeated, the twin boundary migration and the related serrated crack nucleation were no longer observed. Instead, extrusions were generated on the twin boundaries. The fatigue cracks were finally nucleated along the extrusions. When the twinned specimen was annealed, fatigue property was improved. This is because the nucleated twin-boundary cracks were arrested at the edge of twin bands which were highly fragmented by the annealing.

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  Surface modification of carbon nanoballs (CNBs) using a plasma in liquid phase (solution plasma) and preparation of CNB/polyamide 6 (PA6) nanocomposite were demonstrated. Reactive species such as OH radical and H₂O₂ generated from solution plasma oxidized the surface of CNBs and changed into hydrophilic. Mechanical properties (modulus of elasticity in tension and flexural modulus, especially impact strength) of hydrophilic CNB/PA6 composite were improved as compared to PA6 and untreated CNB/PA6 composite. CNBs with hydrophilic surface modified by solution plasma were well-dispersed into PA6 matrix.

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  In general, when thin films of copper (Cu), as a wiring material, and platinum (Pt) are formed on a ceramic material, a thin metal film, such as titanium (Ti), is used as the basal layer. Thus, effective strategy to lower the resistance of the wiring material is to increase the size of crystal grains. However, after annealing, the surface roughness of the wiring increases, and the adhesive strength deteriorates, which has the undesired result that the wiring becomes easily exfoliated. There are many reports in which these effects are attributed to the recrystallization of Pt and the diffusion of Ti. However, there are few reports in which observations of this phenomenon in real time are described. In the present study, we observed the cross-sectional structure of a Pt/Ti-containing thin film and performed dynamic high-temperature in-situ field emission electron gun type-scanning electron microscope (FE-SEM) analyses. A mechanism to explain the above effects is proposed.
   The Pt/Ti thin film was formed by a magnetron sputtering technique onto silicon oxide (SiO₂) substrate. Ti and Pt thin films were generated continuously in a single chamber. The resulting film thicknesses were 50 nm and 500 nm for Ti and Pt, respectively. The cross-sectional structure of each thin film was studied with a dual-beam focused ion beam (FIB)-SEM and ion milling, while high-angle annular dark-field (HAADF) imaging was carried out with a field emission electron gun type-transmission electron microscope (FE-TEM), and the cross-sectional microstructure was evaluated by electron backscatter diffraction (EBSD). In addition, high-temperature dynamic in-situ FE-SEM (Quanta-FEG) was used to observe the surface of the Pt/Ti thin film. After the temperature was increased from room temperature to 1000°C, the temperature of the observed sample was maintained at 1000°C for 30 min. During this time period, we performed reflection electronic imaging (environmental scanning electron microscope mode (ESEM mode)) to obtain dynamic images with a 25 μm×25 μm area.
   The real-time measurement using dynamic high-temperature in-situ FE-SEM indicates that diffusion of Ti occurs along grain boundaries in the Pt thin film. We observed this event as the recrystallization of Pt, which precipitated onto the surface of the Pt thin film. Regarding the action of Ti, when heat treatment was applied to the surface of the Pt/Ti thin film in an oxygen atmosphere, the following events were observed: the Ti thin film under the Pt thin film formed spherical nanoparticles and diffused through the grain boundaries of the Pt thin film. Thereafter, Ti cohered on the surface of the Pt thin film. However, when Pt recrystallized and the size of the crystal grains increased, the grains did not diffuse in the horizontal direction of the film, but began to cover the top of the Pt thin film. The model proposed by Hanzawa et al., in which the adhesive strength of a Pt/Ti thin film on a ceramic substrate deteriorates as the surface roughness of the Pt thin film increases, was proved to be valid through this study.

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