The present work deals with a Laves phase C14 AB2 alloy, namely (TiZr)(VNiMnCrSn)2. The alloy in many ways is a good alternative to a rare earth AB5 alloy with a superior capacity reaching a value of 400 mAh/g. A drawback with this alloy is that it is difficult to activate and therefore it is desirable to develop processing techniques which would readily activate the alloy. In this study we have plasma processed the alloy so as to see if this processing would exercise a positive effect on activation. AB2 powder was therefore fed to plasma torch with 25 kW power. The powders of -325 mesh had a range of particles sizes, the finer ones were evaporated and condensed into nanoparticles less than 100 nm in size. The larger ones spheroidized and were collected in the form of two groups of powders. We have characterized all three groups of powders both chemically and the latter two in terms of electrochemical performance.

The pore structure in nano-porous TiO 2 coating influences the ion diffusion property and photovoltaic performance of dye-sensitized solar cells (DSC). In this paper, TiO 2 coatings were deposited by vacuum cold spray (VCS) using a strengthened nanostructured powder. The pore structure, ion diffusion and dye infiltration properties were examined to understand the deposition mechanism of the coating and the suitability of cold sprayed TiO 2 coating for DSC. It was interestingly found that the pores in the VCS TiO 2 coating presented a bimodal size distribution with two peaks at ~15 nm and ~50 nm, which contributed to a much higher ion diffusion coefficient comparing to that of the conventional unimodal-sized nano-porous coating. The dye infiltration and loading are beneficial from the bimodal size distribution of the pores. Based on the impact behavior of the spray powder, a deposition model was proposed to explain the deposition mechanism of the strengthened nanostructured powder during vacuum cold spray.

Samaria-doped ceria (SDC) has become a promising material for the fabrication of intermediate-temperature, metal-supported solid oxide fuel cells (SOFCs). While typical SOFC materials, such as yttria-stabilized zirconia (YSZ), require high temperatures (> 700°C) to exhibit suitable ionic conductivity for high cell performance, SDC displays similar ionic conductivities at lower temperatures (600°C – 650°C). The atmospheric plasma spray (APS) process is a promising technique for manufacturing metal-supported SOFCs. In this study, the in-flight characteristics, such as particle velocity and surface temperature, of spray-dried SDC agglomerates were analyzed at various plasma spray conditions using the DPV-2000 in-flight particle sensor manufactured by Tecnar Automation. Coatings of SDC were applied on stainless steel substrates using a range of spray conditions, and their resulting microstructures and deposition efficiencies were analyzed. It was found that particle temperature could be related to the specific plasma energy, and that coating porosity was related closely to the measured average particle temperature.

Suspension plasma spraying (SPS) is regarded as a promising way to produce new coating structures with improved properties. In this study, SPS was studied as a possible manufacturing process for producing thin MnCo 2 O 4 spinel coatings for used as protective coatings in metallic interconnector plates of SOFC’s. Suspension of nanosized MnCo 2 O 4 powder and ethanol was thermally sprayed by using an F4-MB plasma gun with radial suspension feeding. The influence of spraying parameters, such as plasma gas composition, total gas flow, current and spraying distance for coating architecture was studied by using field-emission scanning electron microscopy (FESEM) and X-ray diffraction method (XRD). Spraying parameters had a strong influence on the coating structure and composition. Coating with the most homogenous structure were formed when sprayed with the low energy spraying parameters whereas high energy parameters resulted in formation of a columnar microstructure containing larger cobalt rich areas.

Ceramic layers, such as yttria-stabilized zirconia or scandia-stabilized zirconia, used for functional layers of solid oxide fuel cells, i.e. the gas tight oxygen ion conductive electrolyte or as ceramic component in the porous cermet anode, were obtained by the Solution Precursor Plasma Spray (SPPS) process. The influence of different solvent types on microstructure was analyzed by comparison of coatings sprayed with water-based solution to ethanol-based one. Use of solvent with low surface tension and low boiling point enhances splat formation, coating microstructure and crystalline structure. Parameter adjustment to receive coatings from nitrate solutions with ethanol as solvent was carried out. Results of Raman spectroscopy indicate that an intermediate of both nitrates (zirconyl and scandium nitrate hydrate) was deposited.