Structure and phase formation of ion-plasma vacuum-arc Zr-B-Si-C-Ti-(N) coatings during deposition

Zr-B-Si-C-Ti-N and Zr-B-Si-C-Ti coating systems were produced by arc-PVD technique. For their deposition, a combined titanium cathode with a ZrB2-SiC insert was used. Deposition was carried out in a residual atmosphere of N2 and Ar. Coatings structure and composition were investigated. The Zr-B-Si-C-Ti coating is characterized by an amorphous-nanocrystalline structure. In this case, nanocrystallites were formed from complex (Zr, Ti) C, and the amorphous structure fraction is formed mainly by phases based on zirconium and silicon. The second system, deposited in a nitrogen residual atmosphere, Zr-B-Si-C-Ti-N, has a predominantly amorphous structure. Such a structure is formed mainly from borides, nitrides, carbides and complex compounds of zirconium, silicon and titanium.

Electroplating of Pure Aluminum from [HMIm][TFSI]–AlCl3 Room-Temperature Ionic Liquid

Electrodeposition of aluminum and its alloys is of great interest in the aerospace, automobile, microelectronics, energy, recycle, and other industrial sectors, as well as for defense and, potentially, electrochemical printing applications. Here, for the first time, we report room-temperature electroplating of pure aluminum on copper and nickel substrates from an ionic liquid (IL) consisting of 1-Hexyl-3-methylimidazolium (HMIm) cation and bis(trifluoromethylsulfonyl)imide (TFSI) anion, with a high concentration of 8 mol/L AlCl3 aluminum precursor. The aluminum deposits are shown to have a homogeneous and dense nanocrystalline structure. A quasi-reversible reaction is monitored, where the current is affected by both charge transfer and mass transport. The electrocrystallization of Al on Ni is characterized by instantaneous nucleation. The deposited Al layers are dense, homogeneous, and of good surface coverage. They have a nanocrystalline, single-phase Al (FCC) structure, with a dislocation density typical of Al metal. An increase in the applied cathodic potential from −1.3 to −1.5 V vs. Pt resulted in more than one order of magnitude increase in the deposition rate (to ca. 44 μm per hour), as well as in ca. one order of magnitude finer grain size. The deposition rate is in accordance with typical industrial coating systems.

Mirror-Like Bright Al-Mn Coatings Electrodeposition from 1-Ethyl-3 Methylimidazolium Chloride-AlCl3-MnCl2 Ionic Liquids with Pyridine Derivatives

The effects of three pyridine derivative additives, 4-hydroxypyridine, 4-picolinic acid, and 4-cyanopyridine, on Al-Mn coatings were investigated in 1-ethyl-3-methylimidazolium chloride-AlCl3-MnCl2 (EMIC-AlCl3-MnCl2) ionic liquids. The smooth mirror-like bright Al-Mn coatings were obtained only in the EMIC-AlCl3-MnCl2 ionic liquids containing 4-cyanopyridine, while the matte Al-Mn coatings were electrodeposited from EMIC-AlCl3-MnCl2 without additives or containing either 4-hydroxypyridine or 4-picolinic acid. The scanning electron microscope and X-ray diffraction showed that the bright Al-Mn coatings consisted of nanocrystals and had a strong (200) preferential orientation, while the particle size of matte Al-Mn coatings were within the micron range. The brightening mechanism of 4-cyanopyridine is due to it being adsorbed onto the cathode to produce the combined effect of (1) generating an overpotential to promote Al-Mn nucleation; (2) inhibiting the growth of the deposited nuclei and enabling them grow preferentially, making the coating composed of nanocrystals and with a smooth surface. The brightening effect of 4-cyanopyridine on the Al-Mn coatings was far better than that of the 4-hydroxypyridine and the 4-picolinic acid. In addition, the bright Al-Mn coating was prepared in a bath with 6 mmol·L−1 4-cyanopyridine and displayed superior corrosion resistance relative to the matte coatings, which could be attributed to its unique nanocrystalline structure that increased the number of grain boundaries and accelerated the formation of the protective layer of the corrosion products.

Preparation, Characterization and Evaluations of Carbon-Doped Ag/Fe/TiO2 Mesoporous Nanocomposite Photocatalyst for Degradation of Methylene Blue and Congo Red

Carbon doped silver/iron/TiO2 nanocomposite is synthesized via the solvothermal technique. Titanium tetraisopropoxide is used as a TiO2 source. The composite samples are characterized by different physicochemical methods, including nitrogen adsorption–desorption analysis, transmission electron microscope, scanning electron microscope, X-ray diffraction, photoluminescence, UV-vis, Fourier-transform infrared, and Energy dispersive X-ray spectroscopy. The nanocrystalline structure of the samples with anatase phase having a tetragonal shape is shown by the XRD and TEM analysis. The photo-absorption boundary of pure TiO2 expands into the visible light region due to composite formation, shown by analysis of UV-vis data. An increase in the degree of electron–hole couple segregation is shown via photoluminescence analysis. N2 adsorption–desorption analysis manifests the higher surface area of samples along with mesoporous nature. The high photodegradation action is shown by the composite samples as compared to pure mesoporous TiO2.

Study on Properties and Heat Treatment Process of Fe75.9Cu1Si13B8Nb1.5Mo0.5Dy0.1

The soft magnetic properties of Fe[Formula: see text]Cu1Si[Formula: see text]B8Nb[Formula: see text]Mo[Formula: see text]Dy[Formula: see text] nanocrystalline alloy were studied which is designed on the basis of the Finemet type alloys. The X-ray diffraction (XRD), transmission electron microscopy (TEM), differential scanning calorimetry (DSC), electric inductance measuring-testing instrument and MATS soft magnetic material AC/DC tester were used to study the effects of the effective permeability ([Formula: see text], saturation magnetic induction ([Formula: see text]), coercivity ([Formula: see text]), and hysteresis losses ([Formula: see text]) at 100[Formula: see text]kHz and 0.2[Formula: see text]T under factors such as different annealing temperatures, different thicknesses, and whether there is a need for transverse field for annealing. The results show that the commercial amorphous alloy ribbons Fe[Formula: see text] Cu1Si[Formula: see text]B8Nb[Formula: see text]Mo[Formula: see text]Dy[Formula: see text] have complete amorphous structure in as-cast state, and [Formula: see text]-Fe nanocrystalline phase precipitates on the amorphous matrix after vacuum annealing. Fe[Formula: see text] Cu1Si[Formula: see text]B8Nb[Formula: see text]Mo[Formula: see text]Dy[Formula: see text] alloy has high [Formula: see text] value and good thermal stability, which can better control the formation of nanocrystalline structure. The transverse magnetic field annealing can greatly increase the [Formula: see text] of the material and reduce the [Formula: see text], which is more significant for the ribbons. The optimum annealing process of Fe[Formula: see text]Cu1Si[Formula: see text]B8Nb[Formula: see text]Mo[Formula: see text]Dy[Formula: see text] alloy is that the transverse magnetic field of 1000[Formula: see text]Gs is applied and the temperature is kept at 833[Formula: see text]k for 30[Formula: see text]min. And the best properties for [Formula: see text] are 1.39[Formula: see text]T, for [Formula: see text] is 4.6[Formula: see text]A/m and [Formula: see text]@1[Formula: see text]kHz, [Formula: see text]@100[Formula: see text]kHz. With the high frequency and miniaturization of electronic components, this material has potential application value.

High Performance Low-Temperature Solid Oxide Fuel Cells Based on Nanostructured Ceria-Based Electrolyte

Ceria based electrolyte materials have shown potential application in low temperature solid oxide fuel cells (LT-SOFCs). In this paper, Sm3+ and Nd3+ co-doped CeO2 (SNDC) and pure CeO2 are synthesized via glycine-nitrate process (GNP) and the electro-chemical properties of the nanocrystalline structure electrolyte are investigated using complementary techniques. The result shows that Sm3+ and Nd3+ have been successfully doped into CeO2 lattice, and has the same cubic fluorite structure before, and after, doping. Sm3+ and Nd3+ co-doped causes the lattice distortion of CeO2 and generates more oxygen vacancies, which results in high ionic conductivity. The fuel cells with the nanocrystalline structure SNDC and CeO2 electrolytes have exhibited excellent electrochemical performances. At 450, 500 and 550 °C, the fuel cell for SNDC can achieve an extraordinary peak power densities of 406.25, 634.38, and 1070.31 mW·cm−2, which is, on average, about 1.26 times higher than those (309.38, 562.50 and 804.69 mW·cm−2) for pure CeO2 electrolyte. The outstanding performance of SNDC cell is closely related to the high ionic conductivity of SNDC electrolyte. Moreover, the encouraging findings suggest that the SNDC can be as potential candidate in LT-SOFCs application.