Microstructure and wear behavior of arc thermal sprayed base-cutter blades in sugarcane harvesters

Base-cutter blades operate close to the soil during sugarcane harvesting, causing a high wear rate. The present study aims to improve the wear resistance of the blades with an economical surface treatment, so wire arc thermal spray was applied with two alternative types of cored wires, namely chrome nickel amorphous (AM) and titanium tungsten carbide (TiW). The microstructure study showed that AM coating contained an amorphous structure, while the TiW coating appeared to have a relatively non-homogeneous structure containing W and Ti carbide dispersion resulting in a higher hardness (876.40 HV0.1) than that of AM coating (814.48 HV0.1). However, after dry sand rubber testing, the AM coating exhibited nearly 2 times lower wear rate than that of the uncoated base-cutter blades or TiW coated ones. Therefore, the arc sprayed AM coating can be an economical approach to extend the service life of the blades

Microstructure and photocatalytic activity of APS coatings obtained from different TiO2 nanopowders

In recent years, intense research has shown that thermal spray techniques, especially atmospheric plasma spraying (APS), can be used to obtain nanostructured TiO2 coatings with effective photocatalytic activity. This study compares the photocatalytic activity of APS coatings obtained from different powders: two nanostructured TiO2 powders produced by spray-drying of two TiO2 nanosuspensions with different solids contents, one spray-dried powder obtained from a suspension comprising a mixture of submicronic and nanometric TiO2 particles and finally one commercial, nanostructured, TiO2 spray-dried powder. All powders were characterised by XRD, FEG-ESEM, granule size distribution, and a flowability evaluation. Feedstock powders were then deposited on austenitic stainless steel coupons using APS. Hydrogen or helium was used as secondary plasma gas. Coating microstructure and phase composition were characterised using FEG-ESEM and XRD techniques; coating anatase content was quantified by the Rietveld method. A significant amount of anatase to rutile transformation was found to take place during the plasma spraying process. In general, the coatings had a bimodal microstructure characterised by the presence of completely fused areas in addition to non-molten areas consisting of agglomerates of anatase nanoparticles. Results also showed that anatase content and porosity of the coatings largely depend on the secondary plasma gas nature, as well as on the characteristics of the feedstock. Finally the photocatalytic activity of the coatings was determined by measuring the degradation of methylene blue dye in an aqueous solution. A reasonably good fit of a first-order kinetic model to the experimental data was found for all coatings. The values of the kinetic constant were related to feedstock characteristics as well as to plasma spraying conditions. (C) 2012 Elsevier B.V. All rights reserved.Bordes, MC.; Vicent, M.; Moreno, A.; Moreno, R.; Borrell Tomás, MA.; Salvador Moya, MD.; Sanchez, E. (2013). Microstructure and photocatalytic activity of APS coatings obtained from different TiO2 nanopowders. Surface and Coatings Technology. 220:179-186. doi:10.1016/j.surfcoat.2012.08.059S17918622

Factor Affecting Textile Dye Removal Using Adsorbent From Activated Carbon: A Review

Industrial company such as textile, leather, cosmetics, paper and plastic generated wastewater containing large amount of dye colour. The removal of dye materials are importance as the presence of this kind of pollutant influence the quality of water and makes it aesthetically unpleasant. As their chemical structures are complicated, it is difficult to treat dyes with municipal waste treatment operations. Even a small quantity of dye does cause high visibility and undesirability. There have been various treatment technique reviewed for the removal of dye in wastewater. However, these treatment process has made it to another expensive treatment method. This review focus on the application of adsorbent in dye removal from textile wastewater as the most economical and effective method, adsorption has become the most preferred method to remove dye. The review provides literature information about different basis materials used to produce activated carbon like agricultural waste and industrial waste as well as the operational parameters factors in term of contact time, adsorbent dosage, pH solution and initial dye concentration that will affect the process in removing textile dye. This review approach the low cost and environmental friendly adsorbent for replacing conventional activated carbon

Sliding Wear Behavior of Al2O3-TiO2 Coatings Fabricated by the Suspension Plasma Spraying Technique

[EN] The friction and dry sliding wear behavior of alumina and alumina-titania near-nanometric coatings were examined. Coatings were obtained by the suspension plasma spraying technique. Dry sliding wear tests were performed on a ball-on-disk tribometer, with an Al2O3 ball as counterpart material, a normal load of 2 N, a sliding distance of 1200 m and a sliding speed of 0.1 m/s. The effect of including TiO2 in the fabricated coatings on friction coefficient behavior, wear rates and wear damage patterns was determined. The addition of TiO2 to the coatings was found to greatly increase wear resistance by, for example, 2.6-fold for 40 wt% of TiO2. The analysis of the wear surface was correlated with microstructural parameters, mechanical properties and wear rates.The authors wish to thank for the Spanish Ministry of Economy and Competitiveness (MAT2012-38364-C03) and the Autonomous Government of Valencia for funding for the stay in SPCTS-UMR CNRS (France), and the French FCENANOSURF consortium funded by the French Ministry and Industry and local governments of Region Centre and Region Limousin.Klyatskina, E.; Espinosa Fernández, L.; Darut, G.; Segovia López, EF.; Salvador Moya, MD.; Montavon, G.; Agorges, H. (2015). Sliding Wear Behavior of Al2O3-TiO2 Coatings Fabricated by the Suspension Plasma Spraying Technique. Tribology Letters. 59(1):1-9. https://doi.org/10.1007/s11249-015-0530-5S19591Pawlowski, L.: The Science and Engineering of Thermal Spray Coatings. Wiley: Hoboken (2008)Lampe, Th, Eisenberg, S., Cabeo, E.R.: Plasma surface engineering in the automotive industry—trends and future prospective. Surf. Coat. 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Technol. 194(1), 58–67 (2005)Sathish, S., Geetha, M., Aruna, S.T., Balaji, N., Rajam, K.S., Asokamani, R.: Sliding wear behavior of plasma sprayed nanoceramic coatings for biomedical applications. Wear 271, 934–941 (2011)Pawlowski, L.: Finely grained nanometric and submicrometric coatings by thermal sparing: a review. Surf. Coat. Technol. 202, 4318–4328 (2008)Xiao, D., Wang, Y., Strutt, P.: Fabrication and evaluation of plasma sprayed nanostructured alumina–titania coatings with superior properties. Mater. Sci. Eng. 301, 80–89 (2001)Tjong, S.C., Chen, H.: Nanocrystalline materials and coatings. Mater. Sci. Eng. 45, 1–88 (2004)Fauchais, P., Montavon, G., Bertrand, G.: From powders to thermally sprayed coatings. J. Therm. Spray Technol. 19, 56–80 (2010)Lima, R.S., Marple, B.R.: Thermal spray coatings engineered from nanostructured ceramic agglomerated powders for structural, thermal barrier and biomedical applications: a review. J. Therm. 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Fabrication NiAl/Cu Composite Powder for Thermal Spray Coating

The NiAl/Cu feedstock powder was prepared by Cu coating on NiAl powder using electroplating technique. The NiAl (NS450, Metco Sulzer) powder was deposited Cu+ from CuSO4 solution at cathode with vary time process (60, 80 and 100 min). The microstructure and element of NiAl/Cu powders were investigated by scanning electron microscope (SEM) and energy dispersion of X-ray (EDX). The morphology of powder were appeared the Cu element holding all of surface NiAl particles. The chemical composition in powder using X-ray diffraction were presented the Cu phase with time process. The phase compounds were presented the Ni, Al and Cu phases. Then, it was appeared the new phase of Cu2O at 100 min time deposited. Therefore, it was low contentThe EDX analysis was supported the Cu cover on the surface NiAl powder. In SEM micrograph of NiAl/Cu cross-section coating were presented the completed structure coating of thermal spray technicque. In addition, the Cu content was improved melted particles by investigated increased lamellar of materials. The Cu lamella was distributed between Ni layers. It was confirmed that NiAl/Cu feedstock powder was fabricated by simple technique.</jats:p

Activated Carbon Preparation from Eucalyptus Wood Chips using Continuous Carbonization - Steam Activation Process in a Batch Intermittent Rotary Kiln

Abstract The production of activated carbon from eucalyptus wood chips by steam activation in a 2000 kg batch intermittent rotary kiln with continuous carbonization - steam activation process at 500°C to 700 °C was studied. The activated carbon products were characterized by FTIR, SEM-EDS, Raman spectroscopy, and BET analyzer. Percent yields, iodine number, and methylene number of the produced activated carbon materials were also measured. It was shown that the percent yield of the activated carbon materials made in the temperatures range of 500°C to 700 °C are 21.63 ± 1.52% − 31.79 ± 0.70% with capacities of 518–737 mg I2/g and 70.11–96.93 mg methylene blue /g. The BET surface area and micropore volume of the activated carbons are 426.8125-870.4732 m2/g and 0.102390–0.215473 cm3/g, respectively. The steam used in the process could create various oxygen containing surface functional groups such as –CO and –COC groups. In addition, it could also increase the amorphous nature of the activated carbon product. These properties of the activated carbon products are increased with increasing steam activation temperature from 500°C to 700°C. As a result, the activated carbon materials produced at activation temperatures of 600 °C and 700 °C have higher adsorption</jats:p

Investigated Microstructure of Al&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt;/13wt%MgO Nanocomposite Coating Prepared by Plasma-Sprayed Technique

The MgO nanowire growth on Al2O3 lamellae has been placed on plasma-sprayed process. The chemical compositions of nanocomposite powders were appeared α-Al2O3 and cubic-MgO phases. After deposited by plasma sprayed coating, the chemical composition has presented major of γ-Al2O3, minor of α-Al2O3 and cubic-MgO phases. The microstructure of Al2O3/13wt%MgO coating was exhibited high density and good distribution of MgO lamellae with thickness in range 241 μm. The MgO nanowire had dispersion that width diameter in range of ~96.5 nm and average of length 884.9 nm, on the Al2O3 lamellae. The result of nanostructure MgO nanowire generation could be explained that the MgO clusters have been depressed on the Al2O3 lamella at the low temperature zone, then deposited and nucleated in during plasma-sprayed. It was found that the new phase of spinel Al2MgO4 form interaction between Al2O3 and MgO. The average porosity of ∼14% was observed in Al2O3/13wt%MgO nanocomposite coating.</jats:p

Activated carbon preparation from eucalyptus wood chips using continuous carbonization–steam activation process in a batch intermittent rotary kiln

AbstractThe production of activated carbon from eucalyptus wood chips by steam activation in a 2000 kg batch intermittent rotary kiln with continuous carbonization–steam activation process conducted at 500 °C to 700 °C was studied. The activated carbon products were characterized by FTIR, SEM–EDS, Raman spectroscopy, and BET analysis. Percent yields, iodine number, and methylene blue number of the produced activated carbon materials were measured as well. It was shown that the percent yields of the activated carbon materials made in the temperature range from 500 to 700 °C are 21.63 ± 1.52%–31.79 ± 0.70% with capacities of 518–737 mg I2/g and 70.11–96.93 mg methylene blue/g. The BET surface area and micropore volume of the activated carbons are 426.8125–870.4732 m2/g and 0.102390–0.215473 cm3/g, respectively. The steam used in the process could create various oxygen containing surface functional groups such as –CO and –COC groups. In addition, it could also increase the amorphous nature of the activated carbon product. These properties of the activated carbon products are increased with increasing steam activation temperature from 500 to 700 °C. As a result, the activated carbon materials produced at activation temperatures of 600 °C and 700 °C exhibit higher adsorption.</jats:p

Effect of thermal spray processes on microstructures and properties of Ni-20%Cr coatings

Ni-20%Cr coatings were produced using different thermal spray techniques, which were spray and fuse, flame spray and arc spray. The Ni-20%Cr powder was sprayed onto a mild steel substrate using the spray and fuse and the flame spray systems, while the Ni-20%Cr wire was sprayed using the arc spray system. SEM microstructures of the coatings suggested the spraying conditions used were able to produce dense microstructures. However, the microstructure of the arc sprayed coatings showed fine lamellar characteristics compared to the coatings prepared by the spray and fuse and the flame spray techniques. Chemical elements and oxide were quantified by EDS-SEM technique. Differences in microstructure and coating characteristics such as content of porosity and oxide due to different processing techniques significantly affected the coating properties such as adhesion strength, hardness and wear rate