Nanocrystalline (NC) metals are known for having excellent strength but perceived to have poor ductility. Miniature tensile tests on NC Ni–Fe measured ultimate strengths of 2 GPa and elongations, by digital image correlation, of up to 10%. Detailed examination of the fracture surface revealed dimpled rupture and cross-section reduction up to 75%, suggesting an intrinsic ability for small grained Ni–Fe to accommodate plasticity. A survey of published studies on NC metals reveals that this behavior is quite common; despite low macroscopic elongation, NC metals often achieve extensive deformation suggesting good intrinsic ductility. Unfortunately, the common sheet-like configuration of NC tensile specimens muddies a simple evaluation of ductility based on elongation, since thin and wide geometries promote localized necking that expedites catastrophic failure. This paper presents a compact review of ductility concepts and literature to interpret the experimental ductility measurements of an electrodeposited nickel alloy.

To obtain highly dispersed and active Pd/C catalysts for formic acid electro-oxidation (FAEO), carbon supported Pd nanoparticles were prepared by three different synthesis methods. The first Pd deposition technique went through the ethylene glycol (EG)-assisted sodium borohydride (NaBH4) reduction process (Pd/C-EG-NaBH4). The second method was the polyol process (Pd/C-EG). The third method was the general NaBH4 reduction process (Pd/C-NaBH4). The results of x-ray diffraction and transmission electron microscopy (TEM) show that the Pd particles on carbon black prepared by the first method have the smallest average size of 3.5 nm with a narrow size distribution. Cyclic voltammetry was used to characterize the electrochemical performance. The peak current density (mass activity) of the Pd/C-EG-NaBH4 for FAEO is 1742 mA/mgPd, which is 1.45 times higher than that of Pd/C-EG and 1.48 times higher than that of Pd/C-NaBH4. Moreover, the experimental results show that the first method has no dependence on the pH value of the synthesis procedure, while the other two methods in the literature are greatly affected by the pH value.

The magnetic anisotropy energy (MAE) of the bulk hcp Co under mechanical deformation is calculated by ab initio density functional theory (DFT) calculations based on the projector augmented wave method. We present a thorough investigation with respect to the choice of exchange-correlation functionals. The generalized gradient approximation (GGA) succeeds in predicting the easy axis of magnetization but underestimates the MAE in comparison to the experimental value, whereas the local density approximation gives a wrong magnetic easy axis. The DFT+U method offers an alternative to increase the MAE value. Unfortunately, as the MAE reaches the experimental value, strong distortions of the lattice parameters are observed. Our results with GGA suggest that a simultaneous reduction of the c/a ratio and increase of the lateral lattice parameter a will strongly enhance the MAE of the material, as observed experimentally. We also found that the MAE in hcp Co is reduced by shear strain.

Morphological and crystallographic effects of a high magnetic field on the primary Al6Mn phase formed during the solidification of hypereutectic Al–3.25wt%Mn were investigated. Without the field, the primary Al6Mn crystals are mainly concentrated in the lower part and reveal a dispersed needle-like shape. In three dimension, the needles are in the form of a quadrangular prism (laterally bound by {110} and preferentially growing along <001>). When the magnetic field is applied, they tend to be distributed homogenously and show some extra agglomerate- or chain-like forms (preferentially extending along <100>). Furthermore, they also tend to preferentially orient with <100> parallel to the field direction. The homogenous distribution is caused by the magnetic viscosity resistance force. The “agglomerates” or “chains” are the result of a “bifurcation effect” due to the breakdown at the sharp edges of the quadrangular prisms. The preferential orientation should be attributed to the magnetocrystalline anisotropy of Al6Mn.

(Ti,Mn)Al/Al2O3 composites were successfully synthesized by reactive hot pressing from Ti–Al–TiO2–MnO2 system. The effect of Mn coming from the Al–MnO2 reaction on the microstructure and mechanical properties of (Ti,Mn)Al/Al2O3 in situ composites was investigated in detail. The results show that the as-prepared products are mainly composed of (Ti,Mn)Al matrix (including a little of Ti3Al) and Al2O3 particles, together with a few amount of Al77.5Mn22.5 phases. The (Ti,Mn)Al matrix is refined and the in situ generated Al2O3 particles distribute uniformly on the boundaries of (Ti,Mn)Al by incorporation of Mn. The (Ti,Mn)Al/Al2O3 composite with 1.92 wt% Mn possesses the best mechanical properties. Compared with Mn-free samples obtained from Ti–Al–TiO2 system, the hardness, flexural strength, and fracture toughness are enhanced by 53.46%, 76.49%, and 64.21%, respectively. The strengthening and toughening mechanisms were also discussed specifically.

SnZn(OH)6 (ZHS) with different morphologies were synthesized by a facile self-templated method at room temperature. It was found that the morphology of ZHS could be controlled by varying the concentration of OH−. The crystalline structure and morphology of the particles were characterized by x-ray diffraction, UV-vis diffuse reflectance spectroscopy, scanning electron microscopy images, and N2 adsorption. The results indicated that the particles had almost uniform monoclinic geometry and uniform size. The photocatalytic activity of ZHS with different morphologies was tested through degradation of Rhodamine B (RhB). Therein, the hollow ZHS showed the highest light catalytic performance due to its large BET surface area, wide band gap, and high crystallinity.

Type 304L stainless steel (SS) samples were used to investigate the correlation between carbide precipitation and triple junction structure derived from crystallographic data obtained by the orientation imaging microscopy associated with electron backscattered diffraction. The samples were solution treated and annealed at different sensitization temperatures/time to introduce various degrees of carbide precipitation at the interface region, thus different degrees of selectivity toward triple junctions. Four models were used to characterize triple junction microstructures: (i) the I-line and U-line model, (ii) the coincident axial direction (CAD) model, (iii) the coincident site lattice (CSL)/grain boundary (GB) model and (iv) the plane matching (PM)/GB model. Among them, the I-line and U-line model is the most effective in identifying special triple junctions, i.e., those exhibiting the beneficial property of high resistance to carbide precipitation. The results showed that the percentage of special triple junctions (I-lines) immune to carbide precipitation, increased from 35 to 80%, as the precipitation became more selective toward triple junction structures due to the corresponding sensitization heat treatment conditions, whereas more than 80% of random triple junctions (U-lines) exhibited susceptibility to carbide precipitation regardless of the sensitization conditions.

The microstructure evolution and diffusion of silicon during heat-treatment and plastic deformation process were studied on the clad plates of Al–Mn/Al–Si aluminum composite fabricated by continuous casting. The results show that when the clad slab is homogenized and hot rolled, silicon diffuses across the interface from the Al–Si alloy (4004) side to the Al–Mn alloy (3003) side and dissolves into the 3003 matrix forming a solid solution. However, after deformation by cold-rolling, the increased driving force for precipitation of the solute elements in the core alloy side along with the abundant defects introduced by the severe deformation promotes the precipitation. Some Mg2Si particles precipitate from the solid solutions to form a transition region close to the interface of the two components. The presented transition area not only benefits the microstructure of the clad sheet but also improves the distribution of the microhardness across the interface, a tendency of gradient transition.

Hyperbranched copper phthalocyanine (CuPc) with uniform spherical morphology has been firstly obtained by ethylene glycol solvothermal synthetic route. The highly dispersed spherical CuPc aggregates with a diameter of ∼500 nm. X-ray diffraction indicated that the molecules were stacked into one-dimensional b-axis aggregate. In addition, the split Soret band together with the broadened and blue-shifted Q-bands in the optical spectra suggested the H (face-to-face) type of interactions in the arrangement of macrocycles in a dense-packed structure. Due to its good symmetrical structure and unique morphology, the hyperbranched spherical CuPc showed excellent broadband microwave absorption behaviors in a frequency of 2–18 GHz. Over an absorber of 5 mm thickness, an absorption bandwidth of 12 GHz corresponding to reflection loss below −10 dB can be obtained. The high value of microwave reflection about −50 dB at the frequency of 16.5 GHz also suggested that the hyperbranched spherical CuPc can be used as promising microwave absorbing materials.

Four-layer multiwalled carbon nanotube (MWNT) thin films were deposited via dropcasting (1 mg/mL MWNTs and 10 mg/mL SDBS) onto filter papers that vary in pore size (1, 5, 25, and 40 µm) to determine the effect of the underlying substrate structure on the in-plane properties of the films. The films (<100 nm thick) were dried using vacuum filtration, and drying in a 65 °C heater with and without a ceramic heating board. DC resistance of the films ranged from 6 × 103 to 9.3 × 109 Ω. Impedance spectroscopy analysis revealed a low and a high frequency inductive response and two parallel R–C circuits for the more conducting thin films. High resistance films were fit by a single RC circuit with a constant-phase element. The differences in the in-plane electrical responses of the different MWNT films can be explained by the degree of carbon nanotube surface coverage, obtained as a result of using different pore size filter papers. The drying method utilized also affected the CNT network formation and its resultant electrical properties.