iTSSe TSS ADVANCED MATERIALS & PROCESSES | JULY/AUGUST 2023 57 iTSSe TSS JTST HIGHLIGHTS EFFECT OF VANADIUM CARBIDE REINFORCED PARTICLES ON WEAR RESISTANCE OF LASER CLADDING Fe-Co DUPLEX COATING Kao Shi, Wenqian Zhou, Yufu Sun, Keyong Su, Xueshan Du, and Zhihao Wang In this study, iron-cobalt (Fe-Co) duplex coating reinforced by vanadium carbide (VC) was prepared on a copper substrate by laser cladding. The experimental results indicated that no cracks and porosity were observed within the cladding layer. The microstructure of the Co-based layer was mainly composed of dendrite and eutectic structures. The grains refined and transformed from dendrites to equiaxed crystals with the increase in VC fraction. (Fig. 3) COLD SPRAY GAS FLOW DYNAMICS FOR ON COLD SPRAY GAS FLOW DYNAMICS FOR ON AND OFF-AXIS NOZZLE/SUBSTRATE HOLE GEOMETRIES Saeed Garmeh, Mehdi Jadidi, Jean-Michel Lamarre, and Ali Dolatabadi Cold spray has been proven to be an economic, green, and eco-friendly spraying technique. Its remarkable deposition rate, flexibility, and low process temperature make it particularly popular for fast and low thermal impact part repairs. Despite cold spray advantages, deposition in discontinuous geometries such as steps, corners, and holes remains a challenge as the under- standing of the gas jet interaction with these geometrical features is still limited. Experimental works have shown that it is challenging to fill holes as some inside areas and the area near the hole entrance remain undeposited or exhibit poorly bonded coating. (Fig. 4) 12 Fig. 3 — Scanning electron microscope image of VC powders. Fig. 4 — Particle footprint for the centered configuration for medium high-pressure cases. TUNING AEROSOL DEPOSITION OF BiVO4 FILMS FOR EFFECTIVE SUNLIGHT HARVESTING Andreas Elsenberg, Thomas Emmler, Mauricio Schieda, Frank Gärtner, and Thomas Klassen Bismuth vanadate (BiVO4) offers high photon efficiencies in solar photo-anodes, due to its suitable semiconductor band gap energies and associated visible light absorption. In well-tuned conditions, such anodes enable green hydrogen generation in photoelectrochemical water splitting cells. Bismuth vanadate films have to ensure high efficiencies in electron/hole pair generation and sufficiently high rates of charge transfer to the conducting substrate and the electrolyte, respectively. (Fig. 5) Fig. 5 — Macrograph showing a homogenous semitransparent BiVO4 coating on a 10 × 10 cm fluorine-doped tin oxide glass substrate plate under illumination by sunlight. The coating was produced by using a mean powder size of 0.6 µm, a process gas pressure of 1.0 bar, and both cyclones in the powder feed line. The darks stripes (vertical lines) correspond to conductive gold tracks to ensure good conductivity in electrochemical cells.
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