•The EIS results show that more Ba could increase the conductivity of BaxCe0.9Y0.1O3-α, and the conductivity of BaxCe0.9Y0.1O3-α increases and then decreases with the increasing of Ba concentration, the conduction is the highest when the Ba content x is 1.05.•Ba concentration dependence of total conductivities and bulk conductivities are similar, Ba non-stoichiometric could effect on grain.•s.p.g.b conductivities of BaxCe0.9Y0.1O3-α increases with the increasing of Ba concentration, when the Ba content x is lower than 1.00, and σs.p.g.b vary little with Ba content x, when x is higher than 1.00. The results indicate that more Ba effect on σs.p.g.b is limited•In humidity air, the bulk conduction of BaxCe0.9Y0.1O3-α is mostly proton conduction, the s.p.g.b. conduction of BaxCe0.9Y0.1O3-α may be proton and oxygen vacancies mixture conductions at low temperature (300 ∼ 600 °C), and the s.p.g.b. conduction of BaxCe0.9Y0.1O3-α may be proton, oxygen vacancies and electron hole mixture conductions at high temperature (600 ∼ 900 °C). The results indicate that large the crystalline grains could cause the proton transfer number increase.BaxCe0.9Y0.1O3-α(x = 0.85 ∼ 1.10) perovskite oxides were prepared, the XRD data reveals that, the raw material CeO2 were found in the specimens, while the contents of Ba x below 1. According to the data of SEM and EDS, the grain interiors size of BaxCe0.9Y0.1O3-α increase with Ba content increasing and none of Ba, Ce, Y enrichment around grain boundaries are observed. At 300 ∼ 900 °C, the total conductivities σtot and bulk conductivities σb of Ba1.05Ce0.9Y0.1O3-α are the highest among these samples. The specific grain boundary conductivities σs.p.g.b of BaxCe0.9Y0.1O3-α increases with the increasing of Ba concentration, when the Ba content x is lower than 1.00, and σs.p.g.b vary little with Ba content x, when x is higher than 1.00. In humidity air, the bulk conduction of BaxCe0.9Y0.1O3-α is mostly OHO• conduction, the s.p.g.b. conduction of BaxCe0.9Y0.1O3-α may be OHO•, VO•• and h• mixture conductions.

A series of single phase Ba1–xKxCe0.8Y0.2O3–δ (x = 0,0.1,0.2,0.3) perovskite oxides were fabricated with 60% potassium excess at 1000 °C for 3 h and further sintered at 1500 °C for 4 h via a citrate-nitrate combustion process. ICP-OES and AAS were used to verify the accurate composition. Conductivities of the perovskite oxides were measured under the atmosphere of 3%O2 and 4.75 kPa H2O/Ar by using AC impedance spectroscopy technique. The bulk conductivity was significantly higher than the grain boundary conductivity, and the total conductivities increased with the increase of the measuring temperature. Among the perovskite oxides studied, Ba0.9K0.1Ce0.8Y0.2O3–δ displayed the highest total conductivity. Additionally, the transport numbers of proton, oxide ion and electron were measured by oxygen and water concentration cell. The results indicated that Ba1–xKxCe0.8Y0.2O3–δ were almost pure ionic conductors at 300-450 °C and mixed protonic-oxide ionic- electronic conductors at 450-900 °C under wet oxygen atmosphere, and Ba0.7K0.3Ce0.8Y0.2O3–δ displayed the highest protonic transport number.

Conducting polymers have been widely used for corrosion protection of metals. Herein, a poly(o-anisidine) (POA)–SiC composite was synthesized by an in situ chemical oxidative polymerization method in a p-toluenesulfonic acid medium. The structure and morphology of the POA–SiC composite were characterized by Fourier transformation infrared spectroscopy (FT-IR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and field emission scanning electron microscopy (FESEM). The thermal stability was studied by thermal gravimetric analysis (TGA) and the electrochemical behavior was studied by cyclic voltammetry (CV) measurements. Subsequently, the synthesized POA–SiC composite was introduced to epoxy resin through a solution blending method, and the three-component POA–SiC/epoxy hybrid materials were applied onto the surface of steel. The corrosion resistance of the POA–SiC/epoxy coating was evaluated by Tafel polarization and electrochemical impedance spectroscopy measurements in a 3.5 wt% NaCl solution and also compared with that of a POA/epoxy coating. The results demonstrated that the POA–SiC composite containing coating has a higher corrosion resistance than that of POA, with a lower corrosion rate and a higher corrosion protection efficiency. The excellent corrosion protection ability of the POA–SiC/epoxy coating is mainly attributed to the micro/nano structure of the POA–SiC composite which promoted a good compatibility with the epoxy resin and thus decreased the pinhole defects of the coating, and a conclusion was drawn that the protection is associated with the barrier effect of SiC nanoparticles, and the passivation and hydrophobic effects of POA. Furthermore, the protection mechanisms of the POA/epoxy coating and the POA–SiC/epoxy coating were also discussed.

•Poly(o-toluidine)/nano ZnO composite was prepared by in situ polymerization method.•The composition and structure of composite were characterized.•Certain physicochemical interaction existed between poly(o-toluidine) and nano ZnO.•Nano ZnO enhanced the barrier properties of the composite coating.•Poly(o-toluidine)/nano ZnO/epoxy coating possessed excellent corrosion resistance.Poly(o-toluidine)/nano ZnO composite was prepared by in situ polymerization of o-toluidine monomer in the presence of nano ZnO particles. Fourier transformation infrared spectroscopy (FT-IR), UV–visible spectroscopy (UV–vis), X-ray diffraction (XRD), Scanning electron microscopy (SEM) and Thermogravimetric analysis (TGA) were used to characterize the composition and the structure of the composite. Poly(o-toluidine)/nano ZnO composite was mixed with epoxy resin through a solution blending method and the poly(o-toluidine)/nano ZnO/epoxy composite coating was coated onto the surface of steel sample, and its corrosion resistance properties were studied by potentiodynamic polarization, electrochemical impendence spectroscopy measurements and immersion test in 3.5% NaCl solution and also compared with that of poly(o-toluidine)/epoxy composite coating, pure epoxy coating and uncoated steel sample. The results showed that the composite coating containing poly(o-toluidine)/nano ZnO composite has higher corrosion resistance than that of poly(o-toluidine). The enhancement of corrosion protection ability of poly(o-toluidine)/nano ZnO composite containing coating may be due to the formation of more uniformly passive layer on steel surface and the addition of nano ZnO particles, which increases the tortuosity of the diffusion pathway of corrosive substances.

Solidification structure is critical in the control of the mechanical properties and quality during the continuous casting process. The thermo-physical properties of 13Cr steel added some rare metals, such as Mo, V, Nb, are measured to better understand the solidification structure of 13Cr bloom. A computational model using CA-FE (cellular automation-finite element) method coupled with heat transfer model is developed to describe the solidification structure in continuous casting process. It is found that the calculated solidification structure is in good agreement with the observed data. The influence of casting speed and superheat on the solidification structure of the bloom is studied in detail. In order to obtain more equiaxed crystal ratio and low degree of the segregation in the bloom, the optimized casting speed 0.6 m/min and superheat less than 25 °C are determined for the caster. Using the optimized manufacturing parameters, these samples are 60% with the equiaxed zone ratio of 8%–10% and below the degree of segregation 1.05.

The slag corrosion and penetration behaviors of MgAl2O4, MgAl2O4–ZrO2, MgAl2O4–ZrO2–CaO, Al2O3, and Al2O3–ZrO2–SiC refractories were investigated using the static crucible method at 1873 K for 2 h. The above refractories all displayed excellent slag corrosion resistance, and their corrosion depth was less than 1.10 mm. Al2O3 material was hardly corroded by the molten slag, and its corrosion depth was only 0.05 mm. Their penetration depth ranged from 13.79 to 24.48 mm. Among them, Al2O3–ZrO2–SiC refractories displayed good slag penetration resistance with a penetration depth of 13.79 mm.

Al2O3 based porous ceramic (APC) is prepared successfully by a polymer sponge replica method.1 The main raw material used is white fuzed corundum powder. The effect of zirconium dioxide content (0 – 12 wt.%), sintering temperature (1450 – 1550°C), and holding duration (2 – 6 h) on APC phase composition, macrostructure, microstructure, and properties after sintering, ultimate strength in compression and thermal shock resistance, are studied. Porous ceramic based on Al2O3, exhibiting an ultrafine microstructure, may be prepared by adding ZrO2. It has been detected that APC properties depend to a considerable extent on production process parameters. APC exhibiting considerable porosity (88.9%), good ultimate strength in compression (0.52 MPa), and good thermal shock resistance (19 thermal cycles) may be obtained by firing a specimen containing 8 wt.% ZrO2 at 1500°C and holding for 2 h.

In the past, the electrochemical properties of spinel LiNi0.5Mn1.5O4, i.e. rate capability at room temperature and cycle performance at elevated temperature, were not satisfactory. In this study, the influence of glycolic acid on the electrochemical properties of spinel LiNi0.5Mn1.5O4 was studied. With some amount of glycolic acid as an additional reactant, spinel LiNi0.5Mn1.5O4 was synthesized, and its electrochemical properties were improved. In addition, the mechanism of capacity decay at elevated temperature was also studied, which presents constructive view to further improve the electrochemical properties of spinel LiNi0.5Mn1.5O4.

A solid state reaction method was used to prepare the perovskite-structured compounds BaZr1−xYxO3−α (x=0, 0.05, 0.1, 0.15, 0.2, 0.25, 0.3). The X-ray diffraction (XRD) pattern indicated that the target perovskite phases were obtained. With increasing Y concentration the unit cell parameters of BaZr1−xYxO3−α samples were expanded, and Y doping became more difficult. However, high synthesis temperature is helpful to promote Y doping. The SEM results showed that the samples exhibited poor sinterability with increasing Y-doping content. Thermal gravimetric (TG) curves analysis showed the more mass decreasing of BaZr1−xYxO3−α (0≤x≤0.3) samples at high temperature with more Y doping and more proton introducing. The electrochemical impedance spectra (EIS) of specimens showed that conductivities of BaZr1−xYxO3−α (0≤x≤0.3) increased with increasing temperature from 300 to 900 °C in wet air. At 900 °C, the conductivity of BaZr1−xYxO3−α (0≤x≤0.3) first increased with increasing doped amount of Y, and reached the highest value of 1.07×10−3 S/cm when x was 0.2, then decreased gradually with further increasing Y content. At 600 °C, BaZr0.75Y0.25O3−α displayed the highest conductivity, while the conductivity of BaZr0.7Y0.3O3−α was the highest at 300 °C. The results indicated that there should be an optimum Y doping concentration yielding the highest conductivity at a constant temperature, and the optimum Y doping concentration should increase in the humidity atmosphere as the temperature decreases. So increasing the Y-doping concentration is helpful to improve the conductivities of BaZr1−xYxO3−α materials at low temperature.Y-doping concentration dependence of the conductivity isotherm at 300, 600 and 900 °C

Spinel compounds LiNi0.5Mn1.3Ti0.2O4 (LNMTO) and Li4Ti5O12 (LTO) were synthesized by different methods. The particle sizes of LNMTO and LTO are 0.5–2 and 0.5–0.8 μm, respectively. The LNMTO/LTO cell exhibits better electrochemical properties at both a low current rate of 0.2C and a high current rate of 1C. When the specific capacity was determined based on the mass of the LNMTO cathode, the LNMTO/LTO cell delivered 137 mA·h·g−1 at 0.2C and 118.2 mA·h·g−1 at 1C, and the corresponding capacity retentions after 30 cycles are 88.5% and 92.4%, respectively.

Polycrystalline Y1−xCaxF3−x (x = 0.23 to 0.29) solid electrolyte samples were prepared by direct synthesis method, and their impedance spectra were measured in air at different temperatures. Results show that the conductivity is on the order of 10−5 to 10−2 S·cm−1 at 673 to 1023 K, and the activation energy ranges within 1.15 to 1.40 eV. The yttrium sensors were assembled with Y0.75Ca0.25F2.75 solid electrolyte and used to determine the activity of yttrium dissolved in liquid Al-Y alloys at 1033 K, while the accuracy of the yttrium sensors was identified by simultaneously measuring the oxygen content with a counterpart oxygen sensor. The variations of measured EMF with yttrium concentration are well coupled to each other between the yttrium cell and the oxygen cell and comply with the deoxidation law of active metals. In liquid aluminum, the activity coefficients of solute yttrium in infinite dilution state and the standard free energy change of yttrium dissolved at 1033 K were assessed as follows: \( \gamma ^{\rule[1pt]{5pt}{.4pt}{\kern-4.5pt}o}_{{\text{Y}}} = 0.0013,{\text{ }}\Delta G^{\rule[1pt]{5pt}{.4pt}{\kern-4.5pt}o}_{{\text{Y}}} = - 106.90{\text{ KJ}} \times {\text{mol}}^{{ - {\text{1}}}} \).