We report on the formation of highly flexible and transparent TiO2/Ag/ITO multilayer films deposited on polyethylene terephthalate substrates. The optical and electrical properties of the multilayer films were investigated as a function of oxide thickness. The transmission window gradually shifted toward lower energies with increasing oxide thickness. The TiO2 (40 nm)/Ag (18 nm)/ITO (40 nm) films gave the transmittance of 93.1% at 560 nm. The relationship between transmittance and oxide thickness was simulated using the scattering matrix method to understand high transmittance. As the oxide thickness increased from 20 to 50 nm, the carrier concentration gradually decreased from 1.08 × 1022 to 6.66 × 1021 cm−3, while the sheet resistance varied from 5.8 to 6.1 Ω/sq. Haacke's figure of merit reached a maximum at 40 nm and then decreased with increasing oxide thickness. The change in resistance for the 60 nm-thick ITO single film rapidly increased with increasing bending cycles, while that of the TiO2/Ag/ITO (40 nm/18 nm/40 nm) film remained virtually unchanged during the bending test.

Porous carbon nanospheres (PCNSs), with a diameter of about 100 nm and porous structure, were synthesized by a hydrothermal method. Then, poly(3-hexylthiophene):PCNS (P3HT:PCNS) composite films were prepared by a spin-coating method using PCNS and P3HT mixtures in a chlorobenzene solution. The effects of mixture ratio, revolving speed, suspension concentration during spin coating, and annealing on the optical properties of P3HT:PCNS composite films were investigated. The results indicate that PCNSs exhibit an energy level matching with P3HT and the optical properties of the P3HT:PCNSs depend strongly on mixture ratio, revolving speed, and suspension concentration during spin coating. A 2:1 ratio of P3HT to PCNSs, suspension concentration of 20 mg/mL (P3HT), and spinning rate of 2000 rpm are appropriate for fabricating P3HT:PCNS composite films, and annealing increases the crystallinity of P3HT, resulting in enhanced visible light absorption and increased charge transport in composite films.

Monophasic Sn1−xCoxO2 (x = 0.05, 0.10, and 0.15) nanoparticles with tetragonal structure have been successfully synthesized by solvothermal method using oxalate precursor route. Powder x-ray diffraction and selected area electron diffraction studies confirmed highly crystalline cassiterite SnO2 structure. The contraction of lattice constants confirmed the incorporation of Co2+ in SnO2 host lattice. Hexagonal nanoparticles with average grain size of 8–13 nm have been formed. With the increasing Co content, the decreasing crystallite size of SnO2 with increasing surface areas from 194 to 219 m2/g was found. The percentage reflectance increases on increasing the cobalt concentration, and a noticeable blue shift appeared. The band gap was found to be 3.85, 3.91, and 4.09 eV, respectively. Co-doped SnO2 showed distinct magnetic behavior with different Co2+ concentration. For x = 0.05 and 0.10, nanoparticles showed paramagnetism with antiferromagnetic interaction, however, on further increasing x = 0.15, the nanoparticles showed canted antiferromagnetic coupling.

In the present work, the Li2ZnTi3O8 ceramics were prepared via the solid-state reaction method, afterward annealed at 800 °C in a time variation from 4 to 20 h. The ordering, microstructures and dielectric properties were investigated using x-ray diffraction, scanning electron microscopy, network analyzer, and Raman spectroscopy. The most significant enhancement of quality factor is obtained in the sample annealed for 20 h, while the dielectric constant and temperature coefficient of resonant frequency change slightly. This result mainly attributes to the enhancement of ordering, which could be related to the increase in the Zn–O bond strength in ZnO4 tetrahedra. Meanwhile, the full-width at half-maximum of A1g mode decreased with higher annealing time, which suggested less variation in the Zn–O bond length and a higher degree of ordering. The best combination of microwave dielectric characteristic is obtained in the sample annealed at 800 °C for 20 h: Q × f = 112,400 GHz, εr = 24.500, and τf = −11 ppm/°C.

Micro/nanostructured goethite (α-FeOOH) was synthesized by a low-temperature water bath method based on the reaction of urea and FeSO4•7H2O at 95 °C. It has been shown that the as-prepared α-FeOOH consists of nearly spherical particles with about 0.5–1 μm in diameter. The microsized α-FeOOH particles are urchin-like in morphology and composed of nanosized leaf-like objects, with about 150–200 nm in length and about 30–50 nm in width, in radial arrangement, showing high specific surface area (∼118 m2/g). The formation of such urchin-like α-FeOOH could be described by a two-step process, or formation of spherical particles, and ethylene glycol-adsorption induced preferential growth of nanoleaves on the preformed spherical particles. Importantly, such micro/nanostructured α-FeOOH has exhibited much higher photocatalytic activity to the organic pollutants, such as Rhodamine 6G, and better re-usable performances than the goethite nanorod powders, exhibiting the good application potential in the environmental treatment. This study could provide a useful material for environmental pollution treatment.

A phase transfer method was developed to prepare Mg(OH)2 nanosheets and a subsequent adsorption–calcination process was followed to obtain lamellar MgO nanostructures. The as-prepared MgO nanosheets also showed a superior adsorption property of Congo red. Transmission electron microscopy and x-ray diffractometer results indicated that the as-obtained Mg(OH)2 was plate-shaped with a hexagonal crystal structure where MgO possessed a lamellar structure with a cubic phase. The maximum adsorption capacities of Mg(OH)2 and MgO were reached up to 1820 and 2650 mg g−1, respectively. The high adsorption capacity might be related to the particle geometry and large surface area (87.97 m2 g−1 for Mg(OH)2 and 132.31 m2 g−1 for MgO). The adsorbents can be easily regenerated for five times without any significant loss in their adsorption property. The adsorption behaviors of the Mg(OH)2 and MgO adsorbents showed that the adsorption kinetics and isotherms were in good agreement with pseudo-second-order rate equation and Freundlich adsorption model.

This research is devoted to the study of the effect of grain size and structural disorders on the melting behavior of Al nanocrystals under nonequilibrium conditions. The results indicate that Tm is constant and similar to Tm of perfect crystal for nanocrystals of 14 nm and higher. But, by a decrease in the grain size, Tm is significantly reduced. In addition, by further decrease in the size of the grain up to about three times the value of Al-lattice parameter, the behavior of the melt will be similar to the amorphous phase. Since it seems that these behaviors are related to high percentage of grain boundaries in nanocrystalline materials, the structural disorders of the atoms in different regions of nanocrystalline samples are separately studied during heating. The results show that premelting of boundary regions causes the melting process of nanostructure materials to be done within one temperature limit instead of at one temperature point.

Heat-resistant Al–8.5Fe–1.3V–1.7Si (wt%) aluminum alloy components were fabricated using selective laser melting (SLM). The as-built samples were examined in terms of density, chemical composition, surface morphologies, microstructures, and mechanical behavior. The results show that nearly full dense samples with the relative density of 99.3% can be produced. The chemical composition of the deposited material is close to that of the powder, presenting a limited aluminum loss and a low oxygen pickup. The SLM specimens consist of three typical zones: the fusion zone (FZ), the remelting border zone (RBZ), and the heat-affected zone (HAZ). Ultrafine continuous cellular α-Al networks are observed in the FZ. The HAZ exhibits fine rounded Al12(Fe,V)3Si particles (10–70 nm) distributed homogeneously in the α-Al matrix, while the rectangle-like AlmFe-type phase (m = 4.0–4.4) with 100–500 nm in size is preferably formed in the RBZ. The microhardness of the parts shows directional independent, with a mean value of 246 HV0.1.

In the present work, Cu–Al alloys were processed by surface mechanical attrition treatment (SMAT) under both room and liquid nitrogen temperature (LNT) conditions. In contrast to room temperature (RT) SMAT, dynamic recovery and recrystallization were largely suppressed during the LNT process. A gradient microstructure was obtained due to the gradient strain and strain rate impacted onto the sample. Microhardness measurement showed that the hardness values gradually decreased from the top surface to the central region. The local hardness of the top surface layer of the LNT and RT SMAT Cu–4.5% Al samples reached maximum values of 1.52 and 1.28 GPa, respectively. The Cu–4.5% Al alloy exhibited an improved yield strength of ∼496 MPa and a higher ductility (compared with literature data of Cu–Al alloys synthesized traditional severe plastic deformation methods) of 15.4% after the LNT SMAT process. A brittle-ductile failure pattern was easily distinguished after fracture. Moreover, the LNT SMAT is a low-cost process with high productivity and can be applied to various types of metallic production.

The fracture strength of β-Mg17Al12 and τ-Mg32(Al, Zn)49 intermetallic coatings on AZ91E Mg alloy was investigated using a nanoindentation-based microcantilever bending technique. A set of micrometer-sized cantilevers with varying dimensions were machined using focused ion beam milling. A nanoindenter was then used to apply an increasing bending load until each cantilever fractured. The corresponding linear-elastic finite element models were created to simulate the deflection of the cantilevers and the fracture strength σm was derived from the models. The results showed that the fracture occurred at the root of the cantilever where the tensile stresses were highest; the average fracture strengths of the β-Mg17Al12 and τ-Mg32(Al, Zn)49 phases were 1.76 and 1.05 GPa, respectively. The potential sources of error are also discussed.

The formation of deformation and recrystallization textures has been investigated in a Ni7W alloy after heavy cold rolling and subsequent annealing at different temperatures. Cold rolling to a von Mises strain of 4.17 produced a mix of rolling texture that lies between classical brass- and copper-type rolling textures, with the fraction of S({123}<634>), brass({110}<112>), and copper({112}<111>) orientations being 33, 28, and 13%, respectively. The fraction of rolling texture for the deformed Ni7W alloy samples increased slightly during recovery, was then consumed significantly during recrystallization, and dropped to 22% after being annealed at 800 °C for 1 h. The fraction of cube({001}<100>) orientation increased to 26% after primary recrystallization, whereas other random orientations of 43% formed in the Ni7W alloy samples. Further annealing promoted cube grain growth, which lead to a significant strengthening of the cube texture and to a significant loss in high angle boundary (HAB). The fractions of cube texture and HAB of the Ni7W alloy substrate were 92.1 and 27.8%, respectively, after annealing at 1200 °C for 1 h.

An alloy with the composition of Mg–3.7Zn–0.3Y–0.3Gd (in at.%) which contains quasicrystal phase was studied by multiple means. The as-cast alloy has dendritic structure and consists of α-Mg, I-phase, W-phase, and Mg–Zn precipitations. The alloy was forged one pass and annealed at 440 °C for 4 h, then followed by two passes of compressions. Eutectics were crushed and partially dissolved after deformation and annealing. The tensile strength increased after each forge pass. Submicron scale particles precipitated all around the grains during the deformations, and the amount of precipitations was proportional to the amount of deformations. These precipitated particles were observed by high resolution transmission electron microscopy (TEM). The existence of rhomboid W'-phase with face center cubic (FCC) structure and globular I-phase was confirmed. A quasi-periodicity lamellar phase combined with I-phase was founded, which was considered to be the transient phase between I-phase and W'-phase. This phase had orientation relationship with $\left( {1\bar 101} \right)$ of α-Mg basis and one of the 5-fold planar of the I-phase.

The subject of hot ductility in C–Mn steels has been the focus of interest for a long time in materials science and engineering. However, the mechanism of loss in hot ductility continues to be unclear. In the present paper, the experimental hot ductility data in C–Mn steels involve: (i) a ductility trough appears at a certain temperature when the sample is held for a certain time at various temperatures after cooling quickly from a higher temperature; (ii) the ductility healing phenomenon which occurs with the duration of holding time; (iii) the ductility deteriorates with the increase of temperature difference between solution treatment temperature and test temperature during a tensile test; (iv) a minimum ductility appears when samples are cooled from a higher temperature to a lower one at a certain cooling rate; and (v) the formation of cavities at grain boundaries during tests. All of these are analyzed and calculated from the perspective of thermally induced nonequilibrium grain-boundary segregation (TNGS). Based on our detailed analyses, the loss in hot ductility of C–Mn steels is ascribed to TNGS of impurities.

The hot deformation behavior of X45CrSi93 valve steel was investigated by a series of compression and tensile tests by means of the Gleeble-1500 simulator and microstructural analyses. The experimental results show that the flow stress decreases with the increasing temperature between 850 and 900 °C followed by an abnormal increase with the increasing temperature between 900 and 1000 °C under the compressive conditions. A normal decrease of the flow stress is continued with the increasing temperature above 1000 °C. Meantime, the tensile specimen conducted at 1000 °C shows double necking effect. Further microstructural analyses show that the phase transition from α-ferrite to austenite and the solution strengthening caused by carbide dissolution are the main reasons for abnormal variation of flow stress for X45CrSi93. The negative temperature gradient in the tensile specimen results in the symmetrical microstructure and then the double necking phenomenon.

The present study investigates the joining of 5-mm-thick plates of superaustenitic stainless steel, AISI 904L by continuous current (CC) and pulsed current (PC) gas tungsten arc welding (GTAW) using ER2553 and ERNiCrMo-4 fillers. This research article attempts to provide a detailed structure–property relationship of these weldments. Interface microstructure revealed the absence of deleterious secondary phases at the heat affected zone in all the cases. Skeletal delta ferrite morphology at the cap of ER2553 fusion zone and multidirectional grain growth at the ERNiCrMo-4 fusion zone were observed for both the weldments. The average hardness at the fusion zone was found to be higher for PCGTA weldments using ER2553 due to the higher proportions of ferrite. Tensile studies corroborated that the failure occurred at the parent metal in all the cases. Charpy V-notch studies divulged that the CCGTA and PCGTA weldments utilizing ERNiCrMo-4 filler exhibited the greater impact toughness of 69 J and 75 J, respectively. The bend test results conveyed that both the CCGTA and PCGTA weldments using ERNiCrMo-4 exhibited soundness and ductility.