Interatomic potentials are constructed for eight representative binary metal systems covering various structural combinations and thermodynamic characteristics. On the basis of the constructed interatomic potentials, molecular dynamics simulations reveal that the physical origin of metallic glass formation is the crystalline lattice collapsing while solute atoms are exceeding the critical value, thus determining two critical solid solubilities for the system. For a binary metal system, the composition range bounded by the two determined critical solid solubilities is therefore defined as its intrinsic glass-forming range, or quantitative glass-forming ability.

The synthesis of monodisperse magnetite nanoparticles (Fe3O4 NPs) has been widely investigated over the last decade. Among the various synthetic methods, thermal decomposition of iron acetylacetonate, Fe(acac)3, or the premade iron-surfactant complex, was demonstrated to be promising to obtain monodisperse Fe3O4 NPs with controllable size and morphology. However, toxic and expensive precursors or tedious experimental procedures are normally required in these approaches. In this communication, we report a facile chemical top-down method to synthesize monodisperse magnetite NPs by using rust, which is mainly composed of γ-Fe2O3, as the iron source and oleic acid as the capping agent. The particle size, and hence the magnetization, of NPs can be readily controlled by adjusting the rust/oleic acid ratio and reaction temperature. This process is a green chemical approach and is easy to be reproduced and scaled up, which could be developed as an effective way to convert waste materials into high quality nanocrystals.

The biconcave shape and corresponding deformability of the human red blood cell (RBC) is an essential feature of its biological function. This feature of RBCs can be critically affected by genetic or acquired pathological conditions. In this review, we highlight new dynamic in vitro assays that explore various hereditary blood disorders and parasitic infectious diseases that cause disruption of RBC morphology and mechanics. In particular, recent advances in high-throughput microfluidic devices make it possible to sort/identify healthy and pathological human RBCs with different mechanobiological characteristics.

In this paper, the influence of tarnishing film-induced stress and tarnishing film-induced brittle cracking on stress-corrosion cracking (SCC) of brass in Mattsson’s solution are investigated using hydrogen charging. Results showed that the SCC susceptibility of brass in Mattsson’s solution increased with the increase of tarnishing film-induced tensile stress. Also, the film-induced brittle cracking showed little effect on SCC susceptibility. From the results obtained, an improved SCC mechanism is proposed to explain the role of the tarnishing film-induced stress and the film-induced brittle cracking in SCC of brass in Mattsson’s solution. It seems that the film-induced brittle cracking is responsible for crack initiation of ductile brass. Also, the SCC susceptibility of brass in Mattsson’s solution was controlled by the growth rate of tarnishing film. Hydrogen enhanced the SCC susceptibility, which can be ascribed to the fact that hydrogen facilitates the tarnishing film growth.

Precise calibration of the indenter shape is an important procedure in nanoindentation analysis since the indenter geometry enters directly into the most common methods of data analysis in this type of testing. Not only is the geometry required to be known with some precision, but also the sharpness of the tip, especially in the case of pyramidal indenters, is important for the use of indenters for testing hardness in thin film specimens—the most common application of nanoindentation. In this paper, a method of determining the area function and tip radius for a Berkovich indenter is described. It is shown that the tip radius estimated from the area function data is in reasonable agreement with a direct measurement using a calibrated atomic force microscope. It is shown that subjective decisions about tip radius may lead to unjustified rejection of a tip for hardness measurement. A new criterion for tip quality is presented in terms of tip radius and specimen material properties.

This article is devoted to recent progress in the area of in situ electron microscopy (scanning and transmission) and will focus on quantitative aspects of these techniques as applied to the deformation of materials. Selected recent experiments are chosen to illustrate how these techniques have benefited from improvements ranging from sample preparation to digital image acquisition. Known for its ability to capture the underlying phenomena of plastic deformation as they occur, in situ electron microscopy has evolved to a level where fully instrumented micro- and nanomechanical tests can be performed simultaneously.

The anisotropy in the fatigue behavior of rolled Mg–3Al–1Zn alloy between the rolling direction and normal direction to the rolling plane was investigated. The {10-12} twinning–detwinning characteristics were found to play key roles in the anisotropic fatigue deformation behavior by inducing a change in the predominant plastic deformation mechanism, which controlled the flow stress and finally influenced the fatigue resistance by generating mean stress. Energy-based approach was successfully used to describe anisotropic fatigue life behavior.

Eu3+ ion-doped BaY2ZnO5 phosphors were synthesized using a vibrating milled solid-state reaction. The phosphors exhibit a series of Eu3+ ion intra-4f excited state 5DJ (J = 3, 2, 1, 0) transitions under an excitation of 395 nm. The maximum photoluminescence intensity for 5D0 → 7F2 transition (625 nm) was obtained at a Eu3+ ion concentration of 40 mol%; quenching occurred at higher concentrations. The critical distance (Rc) for the 5DJ (J = 3, 2, 1) → 7F1 transition was 18.1 Å, which is longer than that of 6.67 Å for the 5D0 → 7F2 transition, indicating that 5DJ (J = 3, 2, 1) is easier for concentration quench because of the cross-relaxation mechanism. The red emission of the BaY1.6Eu0.4ZnO5 phosphor has CIE chromaticity coordinates of (0.66, 0.34), which are close to the NTSC system standard red chromaticity (0.67, 0.33). BaY1.6Eu0.4ZnO5 may thus be potentially applicable as a red phosphor for ultraviolet light-emitting diodes converted in solid-state lighting technology.

This study reports the generation of periodic parallel silicone strips by simply peeling a silicone sheet, oxidized by UV/ozone, from its bonded substrate. This spontaneous formation of strips is initiated by a mixed mode of separation along the peeling direction and subsequent channeling of initiated cracks. The periodicity of the strips is tuned by the bending strain acting on the silicone sheet during peeling, and the regularity and the locus of failure are determined by the extent of oxidization.

Spherical scratch tests were conducted in individual grains of a randomly oriented polycrystalline body-centered-cubic (bcc) Ti–Nb alloy. For each grain, scratch tests were conducted at four different levels of normal load, which resulted in varying amounts of plastic strain during indentation. The results show a dependence of the horizontal load component on the crystallographic orientation and on the amount of plastic strain. The component of the horizontal force that resulted from plastic deformation was found to correlate with the active slip systems for the particular grain orientation.

Halloysite nanotubes (HNT) reinforced polylactic acid (PLA) nanocomposite fibers were produced using an electrospinning approach for biomedical applications. The PLA/HNT nanocomposite fibers were characterized using x-ray diffraction (XRD) and scanning electron microscopy (SEM). The various factors such as type of solvent, solution concentration, HNT loading and feed rate, affecting the electrospinning process, and the morphology of the nanofibers were investigated, and the optimum values for these parameters are suggested. The results indicated that the addition of dimethylformamide (DMF) to chloroform facilitated the electrospinning process because of the improvement in electrical conductivity and viscosity of the solution. Nanometer-sized fibers were obtained by the addition of HNT to PLA. HNT loadings had a significant effect on the morphology of the nanofibers. Bead-free fibers were produced at feed rates between 1 and 4 mL/h.

The microstructures of two pressureless sintered ceramics, ZrB2 and HfB2 with 20 vol% MoSi2 added, were analyzed by scanning and transmission electron microscopies. Carbides and oxides of the transition metals and MoB were observed to be well dispersed within the boride matrix. Mo5Si3 and Mo5SiB2, with Zr or Hf impurities, were observed at triple grain junctions and showed a partial wetting of the matrix. It was also noticed that the borides had a core-shell structure, which was especially pronounced in the ZrB2-based composite. The experimental results suggest the formation of a Mo–Si–B liquid phase at high temperature, which strongly promoted the densification. The densification mechanisms are discussed in light of the microstructure evolution on sintering, thermodynamic considerations, and the phase diagrams of the species involved.

The present work reports on the conditions of nanoparticle growth and splitting under energetic ion irradiation. Cohesive energy that determines the thermal stability of a given nanoparticle system was calculated by extending surface area difference (SAD) and liquid drop model (LDM). Based on the size-dependent cohesive energy calculations, the interparticle coalescence mechanism is discussed for a ZnS-based nanoparticle system with special reference to a variety of matrices. The interparticle separation is found to play key role in particle–particle coalescence leading to nanoparticle growth or partial evaporation that results in splitting.

Fracture surfaces of Zr-based bulk metallic glasses of various compositions tested in the as-cast and annealed conditions were analyzed using scanning electron microscopy. The tougher samples have shown highly jagged patterns at the beginning stage of crack propagation, and the length and roughness of this jagged pattern correlate well with the measured fracture toughness values. These jagged patterns, the main source of energy dissipation in the sample, are attributed to the formation of shear bands inside the sample. This observation provides strong evidence of significant “plastic zone” screening at the crack tip.