The phase equilibria at 300, 400, 500, and 600 °C in the Ag–Bi–Ni system and 300, 400, and 500 °C in the Cu–Bi–Ni system were experimentally determined by metallography and electron probe microanalysis on equilibrated alloys and diffusion couples. Differential scanning calorimetry was used to measure the temperatures of phase transformations. All the experimental results show that the solubilities of the ternary elements of the binary intermetallic compounds in the Ag–Bi–Ni system are limited. However, the binary intermetallic compounds have some solubilities of the ternary elements in the Cu–Bi–Ni system. No ternary intermetallic compound was found in the Ag–Bi–Ni and Cu–Bi–Ni systems. On the basis of the determined results, the phase equilibria in the Ag–Bi–Ni and Cu–Bi–Ni systems were thermodynamically assessed, and reasonable agreement between the calculated results and experimental data was obtained.

Microstructural changes and phase transformations of an electropulsing-treated (EPT) ZA22 alloy wire were studied using scanning electron microscopy and transmission electron-microscopy techniques. Two stages of phase transformation were detected in the EPT alloy: (i) quenching from the as furnace-cooled (FC) state to the final stable state and (ii) up-quenching from the final stable state back to the as FC state through two reverse phase transformations: T′ + η → α + ε and η′T + ε + α → η′FC. Electropulsing accelerated phase transformation tremendously. It was at least 1200 times faster than the aging process. The mechanism of the electropulsing-induced phase transformations is discussed from the point of view of Gibbs free energy and electropulsing kinetics.

A constitutive theory for metallic glasses is established that is based mainly on the Drucker-Prager model and a free-volume theory. The primary emphasis of this theory is on volume dilatation and its consequences on mechanical responses in metallic glasses that have been known from studies in both experiments and atomistic simulations. We also implemented the constitutive theory in a finite element modeling scheme and conducted numerical modeling of deformation of a metallic glass under plane-strain tension and compression. In particular, we focused our attention on the deviation of the shear band inclination angle, a commonly observed phenomenon for metallic glasses. We found very good qualitative agreement with available experimental data on shear band inclination angle and stress-strain relation. We also give a detailed discussion on different constitutive models, in particular the Coulomb-Mohr model, in the context of predicting the shear band inclination angle.

Nanoporous metals (NPMs) made by dealloying represent a class of functional materials with the unique structural properties of mechanical rigidity, electrical conductivity, and high corrosion resistance. They also possess a porous network structure with feature dimensions tunable within a wide range from a few nanometers to several microns. Coupled with a rich surface chemistry for further functionalization, NPMs have great potential for applications in heterogeneous catalysis, electrocatalysis, fuel cell technologies, biomolecular sensing, surface-enhanced Raman scattering (SERS), and plasmonics. This article summarizes recent advances in some of these areas and, in particular, we focus on the discussion of microstructure, catalytic, and optical properties of nanoporous gold (NPG). With advanced electron microscopy, three-dimensional tomographic reconstructions of NPG have been realized that yield quantitative characterizations of key morphological parameters involved in the intricate structure. Catalytic and electrocatalytic investigations demonstrate that bare NPG is already catalytically active for many important reactions such as CO and glucose oxidation. Surface functionalization with other metals, such as Pt, produces very efficient electrocatalysts, which have been used as promising fuel cell electrode materials with very low precious metal loading. Additionally, NPG and related materials possess outstanding optical properties in plasmonics and SERS. They hold promise to act as highly active, stable, and economically affordable substrates in high-performance instrumentation applications for chemical inspection and biomolecular diagnostics. Finally, we conclude with some perspectives that appear to warrant future investigation.

Nanoporous metals prepared by the corrosion of an alloy can take the form of monolithic, millimeter-sized bodies containing approximately 1015 nanoscale ligaments per cubic millimeter. The ligament size can reach down to the very limits of stability of nanoscale objects. The processes by which nanoporous metals are formed have continued to be fascinating, even though their study in relation to surface treatment, metal refinement, and failure mechanisms can be traced back to ancient times. In fact, the prospect of using alloy corrosion as a means of making nanomaterials for fundamental studies and functional applications has led to a revived interest in the process. The quite distinct mechanical properties of nanoporous metals are one of the focus points of this interest, as relevant studies probe the deformation behavior of crystals at the lower end of the size scale. Furthermore, the coupling of bulk stress and strain to the forces acting along the surface of nanoporous metals provide unique opportunities for controlling the mechanical behavior through external variables such as the electrical or chemical potentials.

A series of Ti-B-C-N thin films were deposited on Si (100) at 500 °C by incorporation of different amounts of N into Ti-B-C using reactive unbalanced dc magnetron sputtering in an Ar-N2 gas mixture. The effect of N content on phase configuration, nanostructure evolution, and mechanical behaviors was studied by x-ray diffraction, x-ray photoelectron spectroscopy, Raman spectroscopy, high-resolution transmission electron microscopy, and microindentation. It was found that the pure Ti-B-C was two-phased quasi-amorphous thin films comprising TiCx and TiB2. Incorporation of a small amount of N not only dissolved into TiCx but also promoted growth of TiCx nano-grains. As a result, nanocomposite thin films of nanocrystalline (nc-) TiCx(Ny) (x + y < 1) embedded into amorphous (a-) TiB2 were observed until nitrogen fully filled all carbon vacancy lattice (at that time x + y = 1). Additional increase of N content promoted formation of a-BN at the cost of TiB2, which produced nanocomposite thin films of nc-Ti(Cx,N1-x) embedded into a-(TiB2, BN). Formation of BN also decreased nanocrystalline size. Both microhardness and elastic modulus values were increased with an increase of N content and got their maximums at nanocomposite thin films consisting of nc-Ti(Cx,N1-x) and a-TiB2. Both values were decreased after formation of BN. Residual compressive stress value was successively decreased with an increase of N content. Enhancement of hardness was attributed to formation of nanocomposite structure and solid solution hardening.

A simple and convenient method for preparing visible light response photocatalyst polypyrrole/TiO2 (PPy/TiO2) nanocomposite was developed. The products were characterized by x-ray diffraction, transmission electron microscopy, atomic force microscopy, ultraviolet-visible, and Fourier transform infrared techniques. The results indicated that the nanohybrid was composed of anatase TiO2 and PPy and exhibited an enhanced visible light-capturing ability. Average diameters of TiO2 and PPy/TiO2 were 18 and 35 nm, respectively. The photocatalytic activity of the nanocomposite was evaluated by the degradation of methyl orange under visible light irradiation. In the presence of PPy/TiO2 nanocomposite, the degradation efficiency of methyl orange of 95.54% could be obtained under visible light irradiation within 120 min. The apparent rate constant was 2.19 × 10−2, which was better than that Degussa P25 nano-TiO2. The sensitization mechanism of PPy/TiO2 photocatalyst was discussed briefly.

As the outer surface of a nanoporous carbon is treated with 16-mercaptohexadecanoic acid, the carbon particles can form a stable suspension in water. When the water phase is compressed, the liquid infiltration behavior in the nanopores becomes significantly different from that of untreated material, suggesting that the inner surface is also modified. After the treatment, the infiltration pressure does not decrease. Therefore, the surface-chain configurations at the inner and outer surfaces must be different, which explains the variations in infiltration pressure and volume.

(Ti1–xSix)Ny (0 ≤ x ≤ 0.20; 0.99 ≤ y(x) ≤ 1.13) thin films deposited by arc evaporation have been investigated by analytical transmission electron microscopy, x-ray diffraction, x-ray photoelectron spectroscopy, and nanoindentation. Films with x ≤ 0.09 are single-phase cubic (Ti,Si)N solid solutions with a dense columnar microstructure. Films with x > 0.09 have a featherlike microstructure consisting of cubic TiN:Si nanocrystallite bundles separated by metastable SiNz with coherent-to-semicoherent interfaces and a dislocation density of as much as 1014 cm−2 is present. The films exhibit retained composition and hardness between 31 and 42 GPa in annealing experiments to 1000 °C due to segregation of SiNz to the grain boundaries. During annealing at 1100–1200 °C, this tissue phase thickens and transforms to amorphous SiNz. At the same time, Si and N diffuse out of the films via the grain boundaries and TiN recrystallize.

Hydroxyapatite (HAp) and brushite (DCPD) are two important compounds of the calcium apatite family with excellent bioactivity and osteoconductive properties in vivo. This work aimed to investigate the stability of HAp nanorods synthesized by the hydrothermal method in acetic acid aqueous solution. The results illuminated that HAp nanorods were converted into hollow nanospheres, and it was found that the concentration and amount of the acetic acid and the reaction time significantly affected the degree of the morphological evolution. Transmission electron microscope, high-resolution transmission electron microscope, and x-ray diffraction were performed for characterizing the samples.

Nanometer-sized intermetallic Mg-Ni and Mg-Cu compound powders were prepared by a physical vapor deposition method (arc discharge) and characterized by means of x-ray diffraction and transmission electron microscopy. Based on an empirical specific heat equation, the effective heat of formation and its temperature dependence were calculated to explain phase formation in nanoscale powders of the binary Mg-Ni and Mg-Cu systems. It is shown that theoretic calculations are in good agreement with the experimental observations.

The microstructural evolution inside adiabatic shear bands in Fe–Cr–Ni alloys dynamically deformed (strain rates > 104 s−1) by the collapse of an explosively driven, thick-walled cylinder under prescribed strain conditions was examined by electron backscatter diffraction. The observed structure within the bands consisted of both equiaxed and elongated grains with a size of ∼200 nm. These fine microstructures can be attributed to recrystallization; it is proposed that the elongated grains may be developed simultaneously with localized deformation (dynamic recrystallization), and the equiaxed grains may be formed subsequently to deformation (static recrystallization). These recrystallized structures can be explained by a rotational recrystallization mechanism.

Many of the porous materials used in laboratory and industrial processes do not have simple regular or crystalline structures. This greatly complicates efforts to characterize them and to understand and optimize their performance for particular applications. This review surveys recent efforts to use simulation and modeling to better understand the structure and performance of several classes of materials, including phase-separated glasses, sol-gel–derived materials, templated silica materials, and activated carbons. Approaches to modeling these materials fall generally into two classes: reconstructions, which generate models based on experimental measurements, and mimetic simulations, which attempt to model the preparation of the materials. While significant progress has been made in many respects, both reconstructive and mimetic transferred currently available are often computationally intensive and not easily transferable between different classes of materials. Finally, since gas adsorption is used widely as a characterization tool for amorphous porous materials and is often the focus of the materials' application, recent developments in simulation and theory appropriate to the study of capillary phenomena in amorphous porous materials are reviewed.

Conducting nylon 6 fibers were prepared by in situ polymerization of aniline on to the fiber surface, after providing a chemical etching treatment to the fibers using chromic acid. The properties of the etched and polyaniline (PANI) coated fibers were evaluated using scanning electron microscopy, x-ray photoelectron spectroscopy, infrared spectroscopy, x-ray diffraction, thermogravimetry, and differential scanning calorimetry. Though the etching process caused a marginal decline in the mechanical properties of the fiber, it provided a reasonably rough surface for PANI adhesion and enhanced the conductivity of the fiber. The conductivity increased from 4.22 × 10−2 to 3.72 × 10−1 S/cm at an etching time of 4 h.

Y2O3:Eu3+ nanophosphor was synthesized by flame spray pyrolysis (FSP) from urea added nitrate based liquid precursor. In this study, urea serves as fuel and subsequently provides additional heat in the flame zone during the synthesis of phosphor particles. The end product shows cubic phase Y2O3:Eu3+ nanophosphor successfully prepared by FSP without heat treatment. The influence of synthesis conditions such as different mol of urea and nitrate source materials in aqueous solution, and doping concentration on luminescent properties, were investigated. The characteristics of nanophosphor such as crystallinity and morphology under various experiments of conditions were carried out by x-ray diffraction (XRD) and field emission-scanning electron microscopy (FE-SEM). The particle size of product was found to be in the range of 20–30 nm from transmission electron microscopy (TEM). In photoluminescence (PL) properties, Y2O3:Eu3+ nanophosphor emitted red light with a peak wavelength of 609 nm when excited with 398 nm wavelength photons.