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Electroless Ni – W – P coating and its nano - WS2 composite / S. Ranganatha in Industrial & engineering chemistry research, Vol. 51 N° 23 (Juin 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 23 (Juin 2012) . - pp. 7932-7940 Titre : Electroless Ni – W – P coating and its nano - WS2 composite : Preparation and properties Type de document : texte imprimé Auteurs : S. Ranganatha, Auteur ; T.V. Venkatesha, Auteur ; K. Vathsala, Auteur Année de publication : 2012 Article en page(s) : pp. 7932-7940 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Preparation  Composite  material Résumé : The ternary alloy Ni―W―P and its WS2 nanocomposite coatings were successfully obtained on low-carbon steel using the electroless plating technique. The sodium tungstate (Na2WO4) concentration in the bath was varied to obtain Ni-W-P deposits containing various Ni and P contents. WS2 composite was obtained with a suitable concentration of Na2WO4 in Ni―P coating. These deposits were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray analysis (EDX) studies. The corrosion behavior was investigated by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) studies in 3.5 wt % NaCl solutions, and the corrosion rates of the coatings for Ni-P, Ni-W-P, and Ni―W―P―WS2 were found to be 2.571 × 10―5, 8.219 × 10―7, and 7.986 × 10―7 g/h, respectively. An increase in the codeposition of alloying metal tungsten (W) enhanced the corrosion resistance and microhardness and changed the structure and morphology of the deposits. Incorporation of WS2 nanoparticles to Ni―W―P alloy coating reduced the coefficient of friction from 0.16 to 0.11 and also helped in improving the corrosion resistance of the coating further. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25990307 [article] Electroless Ni – W – P coating and its nano - WS2 composite : Preparation and properties [texte imprimé] / S. Ranganatha, Auteur ; T.V. Venkatesha, Auteur ; K. Vathsala, Auteur . - 2012 . - pp. 7932-7940. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 23 (Juin 2012) . - pp. 7932-7940 Mots-clés : Preparation  Composite  material Résumé : The ternary alloy Ni―W―P and its WS2 nanocomposite coatings were successfully obtained on low-carbon steel using the electroless plating technique. The sodium tungstate (Na2WO4) concentration in the bath was varied to obtain Ni-W-P deposits containing various Ni and P contents. WS2 composite was obtained with a suitable concentration of Na2WO4 in Ni―P coating. These deposits were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray analysis (EDX) studies. The corrosion behavior was investigated by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) studies in 3.5 wt % NaCl solutions, and the corrosion rates of the coatings for Ni-P, Ni-W-P, and Ni―W―P―WS2 were found to be 2.571 × 10―5, 8.219 × 10―7, and 7.986 × 10―7 g/h, respectively. An increase in the codeposition of alloying metal tungsten (W) enhanced the corrosion resistance and microhardness and changed the structure and morphology of the deposits. Incorporation of WS2 nanoparticles to Ni―W―P alloy coating reduced the coefficient of friction from 0.16 to 0.11 and also helped in improving the corrosion resistance of the coating further. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25990307

Generation of nanocrystalline NiO particles by solution combustion method and its Zn_NiO composite coating for corrosion protection / K. G. Chandrappa in Materials and corrosion, Vol. 63 N° 5 (Mai 2012) 

Public ISBD [article]  in Materials and corrosion > Vol. 63 N° 5 (Mai 2012) . - pp. 445–455 Titre : Generation of nanocrystalline NiO particles by solution combustion method and its Zn_NiO composite coating for corrosion protection Type de document : texte imprimé Auteurs : K. G. Chandrappa, Auteur ; T.V. Venkatesha, Auteur ; K.O. Nayana, Auteur Année de publication : 2012 Article en page(s) : pp. 445–455 Note générale : Génie mécanique Langues : Anglais (eng) Mots-clés : Composite  coating;  corrosion;  heat  treatment;  impedance;  nanocrystalline;  nickel  oxide;  TEM;  XRD Résumé : The nanocrystalline nickel oxide (NiO) particles have been successfully prepared by a simple, fast, economical, and eco-friendly solution-combustion method using Ni(NO3)2· 6H2O (oxidizer) and sugar (dextrose as fuel). The as-prepared compound was calcined for an hour at different temperatures. The synthesized NiO was characterized by XRD, TGA, SEM/EDX, TEM, XPS, FT-IR, and UV–Vis spectral methods. The crystallite sizes of the NiO particles were measured. Rietveld refinement of X-ray data matches the cubic structure with space group of Fm3m (No. 225). The thermal behavior of as-prepared compound was examined. Scanning electron micrographs show uniform cubic like morphology of NiO and its chemical composition was measured. The TEM results reveal that the particle sizes were in the order of 70–80 nm. The red shift was noticed in UV–Vis absorption spectra. As an application part the Zn_NiO composite coating was prepared by electrodeposition method and its corrosion behavior was analyzed by Tafel, impedance and anodic polarization in aggressive medium. En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.201005966/abstract [article] Generation of nanocrystalline NiO particles by solution combustion method and its Zn_NiO composite coating for corrosion protection [texte imprimé] / K. G. Chandrappa, Auteur ; T.V. Venkatesha, Auteur ; K.O. Nayana, Auteur . - 2012 . - pp. 445–455. Génie mécanique Langues : Anglais (eng) in Materials and corrosion > Vol. 63 N° 5 (Mai 2012) . - pp. 445–455 Mots-clés : Composite  coating;  corrosion;  heat  treatment;  impedance;  nanocrystalline;  nickel  oxide;  TEM;  XRD Résumé : The nanocrystalline nickel oxide (NiO) particles have been successfully prepared by a simple, fast, economical, and eco-friendly solution-combustion method using Ni(NO3)2· 6H2O (oxidizer) and sugar (dextrose as fuel). The as-prepared compound was calcined for an hour at different temperatures. The synthesized NiO was characterized by XRD, TGA, SEM/EDX, TEM, XPS, FT-IR, and UV–Vis spectral methods. The crystallite sizes of the NiO particles were measured. Rietveld refinement of X-ray data matches the cubic structure with space group of Fm3m (No. 225). The thermal behavior of as-prepared compound was examined. Scanning electron micrographs show uniform cubic like morphology of NiO and its chemical composition was measured. The TEM results reveal that the particle sizes were in the order of 70–80 nm. The red shift was noticed in UV–Vis absorption spectra. As an application part the Zn_NiO composite coating was prepared by electrodeposition method and its corrosion behavior was analyzed by Tafel, impedance and anodic polarization in aggressive medium. En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.201005966/abstract