Niobium doped dititanium trioxide (Ti₂O₃:Nb) films were deposited on glass substrates, through grid-assisted magnetron sputtering. The Ti₂O₃:Nb films were characterized by X-ray diffraction (XRD), electrical conductivity and optical properties. Film deposition was carried out in two different substrate bias modes: DC and unipolar pulsed. Results show that the negative-pulsed mode improves conductivity and crystallinity. The XRD results show peaks corresponding crystallographic planes of Ti₂O₃. No niobium oxide Nb_xO_y peaks were observed, which indicates that niobium oxide if formed, is amorphous, and/or substituted Nb atoms remain in a solid solution within the Ti2O3 structure. It was observed that "as-deposited" Ti₂O₃:Nb films (without post annealing) are transparent and electrical conductive, with transmittance that reaches 60% in the visible light wavelength despite the considerable thickness of the film and a miminum resistivity of 2x10^-2 Ω.cm which indicates that there is potential for application as Transparent Conductive Oxide (TCO).

In this work Nb-doped TiO2 (TiO2:Nb) films were deposited by reactive sputtering. The substrate was biased with negative pulses to change the energy of the ions nearby the sample surface during the deposition. As consequence, the film crystalline structure and roughness were changed. It was verified that higher energy favours the rutile growth with a higher roughness, even under low temperature as 300°C, and the material structure can be controlled by setting the duty cycle, voltage and frequency of the switched power supply applied to the substrate.

Gas-Shielded Tungsten Arc Welding (GTAW) was modified to a Flux-Cored-Double-Wire GTAW (FCDW-GTAW); in this technique, wires of different compositions are used simultaneously to obtain different microstructures. In the modified GTAW, automatic flux-cored double-wire was used with a combination of four different wires deposited in AISI1020 steel, allowing different microstructures. Pin-on-disk wear tests described by ASTM G99 was used to evaluate the wear coefficients of four hardfacing materials combining Fe–Cr–C, Fe-Cr-C-Nb, Fe-Cr-C-Mo-Nb, and Fe-Cr-C-Mo-Ti alloys. The combination of these wires resulted in a hypoeutectic microstructure with niobium and titanium carbides, with an average hardness of 650 HV_0.3, and hypereutectic microstructures formed by different niobium contents, with a microhardness range from 820 to 1020 HV_0.3. The wear tests were performed without lubrication at room temperature, using a 6.0 mm diameter polished alumina sphere as a counter-body. The total distance covered was 1000 m with a speed of 0.1 m/s, a track radius of 6.0 cm, and an applied load of 10 N. Hardness, microstructure, wear coefficient, and wear mechanisms were compared. The results showed that wear resistance could be differentiated by the predominant wear mechanism: polishing for the hypoeutectic hardfacing and cracking for the hypereutectic ones.

This paper reports the effect of pulsed bias in comparison with DC bias on reactive deposition of Ti6Al4V-N films, obtained by Grid Assisted Magnetron Sputtering. The results obtained by X-Ray diffraction (XRD), Energy Dispersive X-ray Fluorescence Spectrometer (EDX) and Atomic Force Microscopy (AFM) show that bias condition affects the crystalline texture and change the roughness and morphology of the films. The DC bias favors the film crystallinity, however the pulsed bias produces smoother films.

The wear resistance of metals can be improved by using the hardfacing technique. Different processes can produce it with the desirable microstructures and mechanical properties. This study presents an original method, flux-core-double-wire of gas-shielded tungsten arc welding, in which wires of different compositions are used simultaneously to obtain different microstructures. The deposition was controlled through the following parameters: welding speed, deposition current, standoff distance, torch angle, and pulse frequency of wire feed. Four coatings were deposited on AISI 1020 steel substrate by combining the cored wires: Fe–Cr–C, Fe–Cr–C–Nb, Fe–Cr–C–Mo–Nb, and Fe–Cr–C–Mo–Ti. The combination of these wires resulted in a hypoeutectic microstructure with niobium and titanium carbides, with an average hardness of 650 HV_0.3. The hypereutectic microstructures were formed by different niobium contents, with a microhardness range from 820 to 1,020 HV_0.3. The performance of the hardfacing was evaluated in the rubber wheel abrasion test described by ASTM G65, Standard Test Method for Measuring Abrasion Using the Dry Sand/Rubber Wheel Apparatus (Superseded), procedure B. The results revealed that the carbide cracking distinguished the wear resistance, and the hardness was not enough to separate the wear behavior. Still, the volume fraction of carbides was a decisive microstructural parameter.