| 1. |
- Dom, Rekha, et al.
(författare)
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A solar-responsive zinc oxide photoanode for solar-photon-harvester photoelectrochemical (PEC) cells
- 2020
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Ingår i: Nanoscale Advances. - : Royal Society of Chemistry (RSC). - 2516-0230. ; 2:8, s. 3350-3357
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Tidskriftsartikel (refereegranskat)abstract
- A highly efficient, nanostructured, solar-responsive zinc-oxide (SRZO) photoanode has been achieved by utilization of a versatile solution precursor plasma spray (SPPS) deposition technique. For the first time, it is demonstrated that a front-illumination type SRZO photo-anode fabricated with a ZnO/stainless steel (SS-304) configuration can generate an enhanced photo-electrochemical (PEC) current of 390 mA cm(-2), under solar radiation from a solar simulator with an AM1.5 global filter (similar to 1 sun). The SRZO electrode displayed a solar-to-hydrogen (STH) conversion efficiency of 2.32% when investigated for H-2 evolution in a PEC cell. These electrodes exhibited a maximum peak efficiency of 86% using 320 nm photons during incident photon-to-current conversion efficiency measurement. Interestingly, the film lattice of SRZO showed a significant red-shift of 0.37 eV in the ZnO band gap thereby providing solar photon absorptivity to SRZO. Further, an enhanced charge transport property by virtue of increased donor density (similar to 4.11 x 10(17) cm(-3)) has been observed, which is higher by an order of magnitude than that of its bulk counterpart. Efficient optical absorption of solar photons and higher donor-density of SRZO have been thus attributed to its superior PEC performance.
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| 2. |
- Faisal, Nadimul Haque, et al.
(författare)
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Application of Thermal Spray Coatings in Electrolysers for Hydrogen Production : Advances, Challenges, and Opportunities
- 2022
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Ingår i: ChemNanoMat. - : Wiley-VCH Verlagsgesellschaft. - 2199-692X. ; 8:12
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Tidskriftsartikel (refereegranskat)abstract
- Thermal spray coatings have the advantage of providing thick and functional coatings from a range of engineering materials. The associated coating processes provide good control of coating thickness, morphology, microstructure, pore size and porosity, and residual strain in the coatings through selection of suitable process parameters for any coating material of interest. This review consolidates scarce literature on thermally sprayed components which are critical and vital constituents (e. g., catalysts (anode/cathode), solid electrolyte, and transport layer, including corrosion-prone parts such as bipolar plates) of the water splitting electrolysis process for hydrogen production. The research shows that there is a gap in thermally sprayed feedstock material selection strategy as well as in addressing modelling needs that can be crucial to advancing applications exploiting their catalytic and corrosion-resistant properties to split water for hydrogen production. Due to readily scalable production enabled by thermal spray techniques, this manufacturing route bears potential to dominate the sustainable electrolyser technologies in the future. While the well-established thermal spray coating variants may have certain limitations in the manner they are currently practiced, deployment of both conventional and novel thermal spray approaches (suspension, solution, hybrid) is clearly promising for targeted development of electrolysers.
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| 3. |
- Ganvir, Ashish, 1991-, et al.
(författare)
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Characterization of Thermal Barrier Coatings Produced by Various Thermal Spray Techniques Using Solid Powder, Suspension, and Solution Precursor Feedstock Material
- 2016
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Ingår i: International Journal of Applied CeramicTechnology. - : Wiley-Blackwell. - 1546-542X .- 1744-7402. ; 13:2, s. 324-332
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Tidskriftsartikel (refereegranskat)abstract
- Use of a liquid feedstock in thermal spraying (an alternative to the conventional solid powder feedstock) is receiving an increasing level of interest due to its capability to produce the advanced submicrometer/nanostructured coatings. Suspension plasma spraying (SPS) and solution precursor plasma spraying (SPPS) are those advanced thermal spraying techniques which help to feed this liquid feedstock. These techniques have shown to produce better performance thermal barrier coatings (TBCs) than conventional thermal spraying. In this work, a comparative study was performed between SPS- and SPPS-sprayed TBCs which then were also compared with the conventional atmospheric plasma-sprayed (APS) TBCs. Experimental characterization included SEM, porosity analysis using weight difference by water infiltration, thermal conductivity measurements using laser flash analysis, and lifetime assessment using thermo-cyclic fatigue test. It was concluded that SPS coatings can produce a microstructure with columnar type features (intermediary between the columnar and vertically cracked microstructure), whereas SPPS can produce vertically cracked microstructure. It was also shown that SPS coatings with particle size in suspension (D50) <3 μm were highly porous with lower thermal conductivity than SPPS and APS coatings. Furthermore, SPS coatings have also shown a relatively better thermal cyclic fatigue lifetime than SPPS.
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| 4. |
- Ganvir, Ashish, 1991-, et al.
(författare)
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Tribological performance assessment of Al2O3-YSZ composite coatings deposited by hybrid powder-suspension plasma spraying
- 2021
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Ingår i: Surface and Coatings Technology. - : Elsevier BV. - 0257-8972 .- 1879-3347. ; 409
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Tidskriftsartikel (refereegranskat)abstract
- The advent of high-throughput plasma spray systems that allow axial feeding encourages the study of using liquid feedstock for various next-generation functional applications. The current study explores the benefit of such a plasma spray system to deposit hybrid powder-suspension Al2O3-YSZ ceramic matrix composite (CMC) coatings for tribological applications. The tribological performance of the hybrid processed CMC coatings was assessed using scratch, ball-on-plate wear and erosion tests and compared with that of monolithic powder-derived Al2O3 coatings. As-deposited and tribo-tested coatings were characterized using Scanning Electron Microscopy, X-ray Diffraction and Energy Dispersive Spectroscopy to analyse their microstructure and phase constitution. The results showed that the tribological performance of the hybrid powder-suspension Al2O3-YSZ CMC coating was significantly improved by enhancing the wear resistance under scratch, dry sliding ball-on-plate and erosion tests as compared to the conventional APS deposited monolithic Al2O3 coating. About 36% decrease in the dry sliding ball-on-plate specific wear rate and up to 50% decrease in the erosion wear rate was noted in the hybrid powder-suspension Al2O3-YSZ CMC coating as compared to the conventional APS deposited monolithic Al2O3 coating. The study concludes that the hybrid powder-suspension route can create CMC coatings with unique multi-length scale microstructures which can be attractive for combining different tribological attributes in the same coating system.
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| 5. |
- Goel, Sneha, 1993-, et al.
(författare)
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Axial Plasma Spraying of Mixed Suspensions : A Case Study on Processing, Characteristics, and Tribological Behavior of Al2O3-YSZ Coatings
- 2020
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Ingår i: Applied Sciences. - : MDPI. - 2076-3417. ; 10:15
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Tidskriftsartikel (refereegranskat)abstract
- Thermal spraying deploying liquid feedstock offers an exciting opportunity to obtain coatings with characteristics vastly different from those produced using conventional spray-grade powders. The most extensively investigated variant of this technique is Suspension Plasma Spraying (SPS), which utilizes a suspension of fine powders in an appropriate medium. The relatively recent advent of axial feed capable plasma spray systems can enable higher throughputs during SPS, provides the possibility for spraying with longer stand-off distances, and also permit the use of suspensions with higher solid loading. The present work investigates axial plasma sprayed coatings produced using a mixed suspension of fine (submicron or nano-sized) powders of Al(2)O(3)and YSZ as a case study. Deposition of the mixed suspension using axial injection plasma spraying, comprehensive evaluation of characteristics of the resulting coatings, and assessment of their tribological behavior were of particular interest. Evaluation of surface morphology, microstructure, and hardness of the coatings reveals that axial SPS of mixed suspensions provides an exciting pathway to realize finely structured multi-constituent coatings using suspensions with as high as 40 wt.% solid loading. The study of scratch, dry sliding wear, and erosion behavior also specifically shows that the addition of YSZ in the Al(2)O(3)matrix can improve the tribological properties of the coating.
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| 6. |
- Mahade, Satyapal, 1987-, et al.
(författare)
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Exploiting Suspension Plasma Spraying to Deposit Wear-Resistant Carbide Coatings.
- 2019
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Ingår i: Materials. - : MDPI AG. - 1996-1944. ; 12:15
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Tidskriftsartikel (refereegranskat)abstract
- Titanium- and chromium-based carbides are attractive coating materials to impart wear resistance. Suspension plasma spraying (SPS) is a relatively new thermal spray process which has shown a facile ability to use sub-micron and nano-sized feedstock to deposit high-performance coatings. The specific novelty of this work lies in the processing of fine-sized titanium and chromium carbides (TiC and Cr3C2) in the form of aqueous suspensions to fabricate wear-resistant coatings by SPS. The resulting coatings were characterized by surface morphology, microstructure, phase constitution, and micro-hardness. The abrasive, erosive, and sliding wear performance of the SPS-processed TiC and Cr3C2 coatings was also evaluated. The results amply demonstrate that SPS is a promising route to manufacture superior wear-resistant carbide-based coatings with minimal in situ oxidation during their processing.
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| 7. |
- Mahade, Satyapal, 1987-, et al.
(författare)
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Novel wear resistant carbide-laden coatings deposited by powder-suspension hybrid plasma spray : Characterization and testing
- 2020
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Ingår i: Surface & Coatings Technology. - : Elsevier BV. - 0257-8972 .- 1879-3347. ; 399
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Tidskriftsartikel (refereegranskat)abstract
- Thermal spraying with a hybrid powder-suspension feedstock presents a novel approach to conveniently realize coatings with unusual chemistries and unique microstructures. In this study, coatings were deposited by simultaneous spraying of T-400 (Tribaloy-400) powder and Cr3C2 suspension with varying relative feed rates. For comparison, pure T-400 coating was also deposited using powder feedstock via atmospheric plasma spray (APS) route to assess the role of incorporating a hard, finely distributed carbide phase in the coating. SEM (Scanning electron microscopy)/EDS (Energy-dispersive X-ray spectroscopy) investigation of the hybrid coatings revealed a lamellar microstructure with distributed fine carbides. XRD (X-ray diffraction) analysis of the feedstock and hybrid coatings showed the presence of original feedstock constituents, along with some oxides of chromium, in the deposited coating. Hardness measurements on the as-sprayed coatings indicated higher hardness in hybrid coatings than in the pure T-400 coating. The deposited coatings were subjected to scratch testing on polished surfaces as well as on polished cross sections. The scratching response of the coatings was examined by SEM analysis. Results demonstrated that the hybrid coatings possess excellent scratch resistance, superior compared to the pure T-400 coating, which is promising for extending the durability of engineering components operating under severe wear conditions. This was confirmed by abrasion test results which established the superior wear resistance of hybrid coatings. The above hybrid approach is easily extendable to other material systems and can have important implications in the realization of next-generation wear resistant coatings. © 2020 Elsevier B.V.
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