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Coating of Synthesized Molybdenum Nanopowder on Aluminium  [PDF]
S. Ravisubramanian,A. Azad,G. Sakthinathan
Asian Journal of Scientific Research , 2013,
Abstract: Surface quality of industrial components is enhanced by molybdenum coating. Molybdenum which has high wear resistance and corrosion resistance is used to reduce friction between the moving parts. An experimental investigation of coating on the aluminium substrate using molybdenum nanoparticles was carried out by spin and dip coating methods. It was found that uniform coating was obtained by dip coating method compared to spin coating. The hardness measurement carried out by the Vickers hardness test showed that this coating increased the hardness of the surface by 1.84 times.
Bonding of Resin Cement to Zirconia with High Pressure Primer Coating  [PDF]
Chen Wang, Li-na Niu, Ying-jie Wang, Kai Jiao, Yan Liu, Wei Zhou, Li-juan Shen, Ming Fang, Meng Li, Xiang Zhang, Franklin R. Tay, Ji-hua Chen
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0101174
Abstract: Objectives To investigate the effect of air-drying pressure during ceramic primer coating on zirconia/resin bonding and the surface characteristics of the primed zirconia. Methods Two ceramic primers (Clearfil Ceramic Primer, CCP, Kuraray Medical Inc. and Z-Prime Plus, ZPP, Bisco Inc.) were applied on the surface of air-abraded zirconia (Katana zirconia, Noritake) and dried at 4 different air pressures (0.1–0.4 MPa). The primed zirconia ceramic specimens were bonded with a resin-based luting agent (SA Luting Cement, Kuraray). Micro-shear bond strengths of the bonded specimens were tested after 3 days of water storage or 5,000× thermocycling (n = 12). Failure modes of the fractured specimens were examined with scanning electron miscopy. The effects of air pressure on the thickness of the primer layers and the surface roughness (Sa) of primed zirconia were evaluated using spectroscopic ellipsometry (n = 6), optical profilometry and environmental scanning electron microscopy (ESEM) (n = 6), respectively. Results Clearfil Ceramic Primer air-dried at 0.3 and 0.4 MPa, yielding significantly higher μSBS than gentle air-drying subgroups (p<0.05). Compared to vigorous drying conditions, Z-Prime Plus air-dried at 0.2 MPa exhibited significantly higher μSBS (p<0.05). Increasing air-drying pressure reduced the film thickness for both primers. Profilometry measurements and ESEM showed rougher surfaces in the high pressure subgroups of CCP and intermediate pressure subgroup of ZPP. Conclusion Air-drying pressure influences resin/zirconia bond strength and durability significantly. Higher air-drying pressure (0.3-0.4 MPa) for CCP and intermediate pressure (0.2 MPa) for ZPP are recommended to produce strong, durable bonds between resin cement and zirconia ceramics.
Microstructure of Nanostructured Zirconia Coating and Its Thermal Shock Resistance

LIANG Bo,DING Chuan-Xian,

无机材料学报 , 2006,
Abstract: The nanostructured and conventional zirconia coatings were fabricated by an atmosphere plasma spraying technique. The microstructure of the as-sprayed zirconia coatings was analyzed. The results show that the nanostructured zirconia coating is a typical lamellar structure composed of columnar grain about 100nm in diameter. In the nanostructured zirconia coating, the pore is fine and of homogeneous distribution, and there exist a large quantity of small microcracks. The nanostructured zirconia coating possesses better thermal shock resistance than the conventional zirconia coating.
Characteristics of sealed plasma electrolytic oxidation coatings with electrochemical impedance spectroscopy

中国物理 B , 2010,
Abstract: Plasma electrolytic oxidation (PEO) coatings are prepared on aluminium with graphite powders added into the electrolyte. The scanning electron microscopy (SEM) coupled with an energy dispersive x-ray analysis system (EDX) is used to characterize the surface and the cross-section morphologies of the coatings. The electrochemical impedance spectroscopy (EIS) is used not only to evaluate the corrosion resistance but also to analyse the structure of the coating. Results show that graphite powders are embedded in the PEO coating. The corrosion resistances of both the inner barrier and the outer porous layer are greatly improved, and the EIS could give some valuable detailed information about the coating structure.
Thermal barrier coating by electron beam-physical vapor deposition of zirconia co-doped with yttria and niobia  [PDF]
Daniel Soares de Almeida,Carlos Alberto Alves Cairo,Cosme Roberto M. Silva,Maria do Carmo A. Nono
Journal of Aerospace Technology and Management , 2010,
Abstract: The most usual ceramic material for coating turbine blades is yttria doped zirconia. Addition of niobia, as a co-dopant in the Y2O3-ZrO2 system, can reduce the thermal conductivity and improve mechanical properties of the coating. The purpose of this work was to evaluate the influence of the addition of niobia on the microstructure and thermal properties of the ceramic coatings. SEM on coatings fractured cross-section shows a columnar structure and the results of XRD show only zirconia tetragonal phase in the ceramic coating for the chemical composition range studied. As the difference NbO2,5-YO1,5 mol percent increases, the tetragonality increases. A significant reduction of the thermal conductivity, measured by laser flash technique in the zirconia coating co-doped with yttria and niobia when compared with zirconia-yttria coating was observed.
Performance of Tannin/Glycerol-Chromate Hybrid Conversion Coating on Aluminium  [PDF]
Makanjuola Oki
Journal of Materials Science and Chemical Engineering (MSCE) , 2015, DOI: 10.4236/msce.2015.37001
Abstract: A smart hybrid conversion coating has been developed. Modifications of coating solutions with poly-hydroxyl organic materials to reduce the usual mud cracking pattern characteristics of chromate conversion coatings (CCCs) and improve its ability to release inhibitors to corroding sites have been achieved. The smart functionalised chromate conversion coating (SFCCC), developed on aluminium substrate has undergone laboratory checks and commercial runs under factory conditions confirmed its potency in improving corrosion resistance and paint adhesion to metal surfaces. In-service performance of the coating in the past three years is excellent.
Electrolytic surface hardening of steel,castiron and aluminium-bronze  [PDF]
Suhas Keshav Paknik a r
China Foundry , 2006,
Abstract: Electrolytic hardening process w as developed in USSR in the 1950s. The process w as developed but w as not com m ercially exploited. There is no evidence of w ork done on this process in India. The author has done this originalw ork applied to different m aterials like steel, castiron and alum inum -bronze.This paper gives details ofm icrostructuraltransform ations along w ith hardness value achieved. There is vitalscope for this process to becom e viable for surfacehardening and selective hardening ofsm allcom ponents.
Investigation of the Ce-Mn conversion coating on 6063 aluminium alloy
JunJun Zhang,WenFang Li,Jun Du,Dong Han,XiaoPing Zheng
Chinese Science Bulletin , 2010, DOI: 10.1007/s11434-010-3162-z
Abstract: In this paper, the sustainable Ce-Mn chemical conversion coating was fabricated on 6063 aluminium alloy by means of Ce(NO3)3 and KMnO4 as the inhibitors and NaF as the accelerator. The morphologies, composition and valence state of the coating were analyzed by scanning electron microscopy (SEM), energy dispersive spectrometry (EDS) and X-ray photoelectron spectroscopy (XPS), respectively. The results indicated that the Ce-Mn conversion coating was formed. The anticorrosion of the coating was evaluated in 3.5 wt.% NaCl aqueous solution at room temperature by using polarization curve and electrochemical impedance spectroscopy (EIS). It indicated that the treated surface presented better anticorrosion behavior in chloride media than on the original material surface. The corrosion resistance of Ce-Mn conversion coating was about equal to the trivalent chromium conversion coating.
Microstructure and Corrosion Performance of Oxide Coatings on Aluminium by Plasma Electrolytic Oxidation in Silicate and Phosphate Electrolyte
Microstructure and Corrosion Performance of Oxide Coatings on Aluminium by Plasma Electrolytic Oxidation in Silicate and Phosphate Electrolytes

LV Guo-Hua,GU Wei-Chao,CHEN Huan,LI Li,NIU Er-Wu,YANG Si-Ze,

中国物理快报 , 2006,
Abstract: Ceramic coatings are fabricated on pure aluminium by plasma electrolytic oxidation (PEO) in three kinds of electrolyte systems E1: 0.05M NaOH+0.033M Na2SiO3, E2: 0.025M NaOH+0.008M (NAPO3)6 and E3: 0.025M NaOH+0.066M Na2SiO3+0.008M (NAPO3)6]. The voltage-time responses show that the PEO process of E2 has the highest discharging voltage, which results in the biggest pores and heaviest cracks on the surfaces. X-ray diffraction results show that coatings produced in E1 and E3 are mainly composed of γ-Al2O3 and mullite, while coatings produced in E2 are mainly composed of a-Al2O3. After PEO treatment the corrosion resistance of aluminium is improved significantly and the coatings produced in E3 perform the best corrosion resistance.
Determination of factors that significantly affect on fretting of electrolytic NiP coating ОПРЕДЕЛЕНИЕ ФАКТОРОВ, СУЩЕСТВЕННО ВЛИЯЮЩИХ НА ФРЕТТИНГ-ИЗНАШИВАНИЕ ЭЛЕКТРОЛИТИЧЕСКИХ NiP ПОКРЫТИЙ  [cached]
И. Р. Асланян,В. И. Семенов,Л. Ш. Шустер
Vestnik UGATU , 2012,
Abstract: The influence of structural parameters of electrolytic NiP coatings (amount of reinforcing of SiC additives and heat treatment), and wear conditions (load and displacement amplitude) on their wear resistance under fretting were investigated. It is established that the main parameter that negatively influences on the wear resistance of coatings during fretting is the amount of reinforcing SiC additives. Изучено влияние параметров структуры электролитических NiP покрытий (количества упрочняющих добавок SiC и термической обработки), а также условий изнашивания (нагрузки и амплитуды сдвига) на их износостойкость при фреттинге. Установлено, что основным параметром, негативно влияющим на износостойкость покрытий при фреттинге, является количество упрочняющих добавок SiC.
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