Abstract:In this work, a detail effect of nanoparticle loading and improved process parameter on the synthesis of modified Zn-TiO2 electrocodeposited nanocomposite coating was presented. The coatings were performed at constant time of 20 minute at a stirring rate of 400 rpm at temperature of 70 °C. The effect of particle loading and input current on the properties of the electrocodeposited Nanocomposite was studied. The co-deposition was carried out at a current interval between 1.0 and 1.5 A for the coating period. Th… Show more
The effects of temperature and time variances on nano-additives treatment of mild steel during machining was presented in this study. Mild steel of 150 kg mass containing 0.56% carbon was charged into the furnace at melting and pouring temperature of 1539 and 1545 °C respectively. Also charged into the furnace with the mild steel were 0.05% max phosphorous and a bit of sulphur. Thereafter, the sample was cooled and annealed at a temperature of 900 °C for 9 h and then cooled to 300 °C of hardening, normalizing and tempering respectively. The treated samples were then soaked with pulverized in palm kernel shell and barium carbonate (20%) energizer at respective temperatures (800, 850, 900 and 950 °C) and time variances (60, 90 and 120 min) in a muffle furnace. The developed tool was tested on a lathe machine to evaluate its performance. The surface and core hardness, wear resistance and toughness were carried out using the hardness tester, Rotopol–V and impact tester respectively. This is essential for predicting the useful life of the tool in service.
The effects of temperature and time variances on nano-additives treatment of mild steel during machining was presented in this study. Mild steel of 150 kg mass containing 0.56% carbon was charged into the furnace at melting and pouring temperature of 1539 and 1545 °C respectively. Also charged into the furnace with the mild steel were 0.05% max phosphorous and a bit of sulphur. Thereafter, the sample was cooled and annealed at a temperature of 900 °C for 9 h and then cooled to 300 °C of hardening, normalizing and tempering respectively. The treated samples were then soaked with pulverized in palm kernel shell and barium carbonate (20%) energizer at respective temperatures (800, 850, 900 and 950 °C) and time variances (60, 90 and 120 min) in a muffle furnace. The developed tool was tested on a lathe machine to evaluate its performance. The surface and core hardness, wear resistance and toughness were carried out using the hardness tester, Rotopol–V and impact tester respectively. This is essential for predicting the useful life of the tool in service.
“…Ir 16.7 Zn 83.3 /GNP and Ir 25 Zn 75 /GNP showed extremely low current densities at 0.22 mA cm −2 and 0.17 mA cm −2 , respectively. The presence of unwashed KCl phase in Ir/GNP catalyst, confirmed by XRD results, assisted in increasing the conductivity of the catalyst and subsequently enhanced its current density [35]. Furthermore, the current density of the Ir/GNP catalyst decayed slower and reached a higher current density at 1000s in comparison with Ir-Zn/GNP catalysts, which showed high durability and stability.…”
A graphene nanoplatelet (GNP)-supported Ir-Zn catalyst (Ir-Zn/GNP) was fabricated by H 2 reduction to discover an alternative for non-platinum and non-palladium catalysts as an anode catalyst in direct formic acid fuel cell (DFAFC). The obtained Ir-Zn/GNP catalyst with ratio of Ir: Zn=50:50 (Ir 50 Zn 50 /GNP) exhibited better electrocatalytic activity than GNP-supported iridium catalyst (Ir/GNP) for formic acid oxidation. Although the oxidation peak current density of Ir50Zn50/GNP was slightly lower than that of Ir/GNP, the oxidation peak potential shifted more negatively (193 mV) than Ir/GNP with higher value of the ratio of forward scan to reverse the scan peak current (If/Ib). The presence of Zn also enhanced the power density and current generation with increased performance stability in a passive DFAFC cell tests. The improvement of the electrochemical performance was ascribed to the ensemble effect where the addition of Zn could modify the Ir atom arrangement, thereby promoting the oxidation through dehydrogenation pathway. However, extremely high Zn content would inhibit oxidation capability because Zn atoms might reduce the Ir catalytic sites. A new alternative for non-Pt and non-Pd anode catalysts for DFAFC applications was successfully achieved.
“…From the results, the materials behaved excellently and the effect of the ternary nanocomposites in Zn-TiO2 was helpful and novel. In this similar vein, [12] reported data on the outcome of current density relationship on the alloy (super) composite coating using electrolytic method.…”
This study synthesized, characterized and determined the electronic and optical properties of Zn-TiO2, Zn-TiO2-WO3 and Zn-TiO2-SnO2 nano-composite coatings on low carbon steel. It has also determined the effect of these coatings on the corrosion of mild steel in saline environment. This was with a view to produce an active coating to providing alternative to hazardous chromium coating. Active multi functional nano crystalline coatings of the composites were electrolytically fabricated on low carbon steel from Zinc bath, with its Cation and nanoparticulates of TiO2, SnO2 and WO3 were uniformly codeposited in the Zn matrix. The nano-powders were characterized with Scanning Electron Microscope/Energy Dispersive Spectrometer (SEM/EDS) analyses for confirmation of the chemical compositions and purity. The electrocodeposition bath compositions were developed with 120 gram per litre of ZnCl2, 30 gram per litre of KCl along sides with the nanopowders. Other additives including cetylpridinum chloride, 2- Butyne 1,4diol were added as surfactants and Thiourea was added as stabilizer. The coated specimens were sectioned into parts, some of which were characterized with electrical meters and solar simulator to determine the electrical conductivity and solar response of the coated samples respectively. Samples were also subjected to corrosion experiment in 3.5% NaCl (saline) media to study their corrosion resistance properties in the test media through Potentiodynamic polarization method. The results, the electrical conductivity of the generated nano-composite coatings displayed a better electrical conductivity of 2.45E-01Ω-1m-1 which made it a better sensor material and outstanding corrosion resistance with corrosion rate at 0.10116 mm/year. The study concluded that both matrices with the Nano Particulate WO3 and SnO2 can be use as sensor materials but the WO3 matrix showed a better electrical conductivity both in the presence and absence of uv light and enhanced corrosion protection under light and dark conditions, thus a better sensor’s material.
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