Documents disponibles écrits par cet auteur

Electrochemical behavior of Ni[BOND]P[BOND]SiC composite coatings / C. F. Malfatti in Materials and corrosion, Vol. 63 N° 1 (Janvier 2012) 

Public ISBD [article]  in Materials and corrosion > Vol. 63 N° 1 (Janvier 2012) . - pp. 36–43 Titre : Electrochemical behavior of Ni[BOND]P[BOND]SiC composite coatings : Effect of heat treatment and SiC particle incorporation Type de document : texte imprimé Auteurs : C. F. Malfatti, Auteur ; J. Z. Ferreira, Auteur ; C. T. Oliveira, Auteur Année de publication : 2012 Article en page(s) : pp. 36–43 Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Composite  materials  Corrosion  Electrochemical  reactions  Ni[BOND]P[BOND]SiC Résumé : This paper describes the effects of heat treatment and of SiC particle incorporation on the electrochemical behavior and physical structure of Ni[BOND]P (17 at% P) composite coatings. The deposits were obtained by electrodeposition with various contents of SiC particles in the plating bath and heat treated at 420 °C. The physical structure was investigated by inductively coupled plasma atomic emission spectrometry (ICP-AES), X-ray diffraction (XRD), and scanning electron microscopy (SEM – image analysis). The electrochemical behavior of the resultant composite coatings was determined by chronopotentiometry, electrochemical impedance spectroscopy, and potentiodynamic measurements in 0.6 M NaCl solution at pH 6. Heat treatment showed a positive effect on the electrochemical behavior of Ni[BOND]P coatings, shifting the open circuit potential toward less active potentials. The incorporation of SiC particles inhibited pit nucleation on the Ni[BOND]P composite coating, with or without post-heat treatment. However, heat treatment in the Ni[BOND]P[BOND]SiC seemed to induce cracks in the metallic matrix, initiating at the SiC particles, possibly caused by the contraction in the metallic matrix. The cracked structure promoted localized corrosion, while coatings without heat treatment resulted in a general and uniform corrosion. DEWEY : 620.1 ISSN : 0947-5117 En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.200905611/abstract [article] Electrochemical behavior of Ni[BOND]P[BOND]SiC composite coatings : Effect of heat treatment and SiC particle incorporation [texte imprimé] / C. F. Malfatti, Auteur ; J. Z. Ferreira, Auteur ; C. T. Oliveira, Auteur . - 2012 . - pp. 36–43. Génie Mécanique Langues : Anglais (eng) in Materials and corrosion > Vol. 63 N° 1 (Janvier 2012) . - pp. 36–43 Mots-clés : Composite  materials  Corrosion  Electrochemical  reactions  Ni[BOND]P[BOND]SiC Résumé : This paper describes the effects of heat treatment and of SiC particle incorporation on the electrochemical behavior and physical structure of Ni[BOND]P (17 at% P) composite coatings. The deposits were obtained by electrodeposition with various contents of SiC particles in the plating bath and heat treated at 420 °C. The physical structure was investigated by inductively coupled plasma atomic emission spectrometry (ICP-AES), X-ray diffraction (XRD), and scanning electron microscopy (SEM – image analysis). The electrochemical behavior of the resultant composite coatings was determined by chronopotentiometry, electrochemical impedance spectroscopy, and potentiodynamic measurements in 0.6 M NaCl solution at pH 6. Heat treatment showed a positive effect on the electrochemical behavior of Ni[BOND]P coatings, shifting the open circuit potential toward less active potentials. The incorporation of SiC particles inhibited pit nucleation on the Ni[BOND]P composite coating, with or without post-heat treatment. However, heat treatment in the Ni[BOND]P[BOND]SiC seemed to induce cracks in the metallic matrix, initiating at the SiC particles, possibly caused by the contraction in the metallic matrix. The cracked structure promoted localized corrosion, while coatings without heat treatment resulted in a general and uniform corrosion. DEWEY : 620.1 ISSN : 0947-5117 En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.200905611/abstract

The influence of cerium ion concentrations on the characteristics of hybrid films obtained on AA2024-T3 aluminum alloy / C. F. Malfatti in Materials and corrosion, Vol. 63 N° 9 (Septembre 2012) 

Public ISBD [article]  in Materials and corrosion > Vol. 63 N° 9 (Septembre 2012) . - pp. 819–827 Titre : The influence of cerium ion concentrations on the characteristics of hybrid films obtained on AA2024-T3 aluminum alloy Type de document : texte imprimé Auteurs : C. F. Malfatti, Auteur ; T. L. Menezes, Auteur ; C. Radtke, Auteur Année de publication : 2013 Article en page(s) : pp. 819–827 Note générale : Génie mécanique Langues : Anglais (eng) Mots-clés : AA2024-T3;  EIS;  hybrid  films;  RBS;  sol–gel Résumé : This work aimed to study the corrosion behavior of AA2024-T3 aluminum alloy substrates pre-treated with 3 glicidoxypropyltrimethoxysilane (GPTMS) silane layers doped with different cerium ion concentrations. The withdrawal speed of substrates from the sol was 20 cm · min−1. The hybrid films were obtained by dip-coating process and analyzed by scanning electron microscopy (SEM) and energy dispersive spectroscopy, Rutherford scattering spectroscopy (RBS), salt spray test, and electrochemical analyses. The correlation among the results obtained from different analyses was very good and indicated that the addition of Ce ion in the hybrid coating contributed to the corrosion resistance; however, for the high Ce ion concentration, the barrier effect of the hybrid films was deteriorated. The results obtained by RBS showed that the concentration of Ce ion in the hybrid film increased linearly with the concentration of Ce ion in the sol. Moreover, it was verified that, for the nominal concentration of 0.05 M Ce ion in the sol, the Ce atomic fraction increased in the hybrid film, while the Si atomic fraction reduced, indicating the possible modification on the silane network due to the incorporation of Ce ions. En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.201106070/abstract [article] The influence of cerium ion concentrations on the characteristics of hybrid films obtained on AA2024-T3 aluminum alloy [texte imprimé] / C. F. Malfatti, Auteur ; T. L. Menezes, Auteur ; C. Radtke, Auteur . - 2013 . - pp. 819–827. Génie mécanique Langues : Anglais (eng) in Materials and corrosion > Vol. 63 N° 9 (Septembre 2012) . - pp. 819–827 Mots-clés : AA2024-T3;  EIS;  hybrid  films;  RBS;  sol–gel Résumé : This work aimed to study the corrosion behavior of AA2024-T3 aluminum alloy substrates pre-treated with 3 glicidoxypropyltrimethoxysilane (GPTMS) silane layers doped with different cerium ion concentrations. The withdrawal speed of substrates from the sol was 20 cm · min−1. The hybrid films were obtained by dip-coating process and analyzed by scanning electron microscopy (SEM) and energy dispersive spectroscopy, Rutherford scattering spectroscopy (RBS), salt spray test, and electrochemical analyses. The correlation among the results obtained from different analyses was very good and indicated that the addition of Ce ion in the hybrid coating contributed to the corrosion resistance; however, for the high Ce ion concentration, the barrier effect of the hybrid films was deteriorated. The results obtained by RBS showed that the concentration of Ce ion in the hybrid film increased linearly with the concentration of Ce ion in the sol. Moreover, it was verified that, for the nominal concentration of 0.05 M Ce ion in the sol, the Ce atomic fraction increased in the hybrid film, while the Si atomic fraction reduced, indicating the possible modification on the silane network due to the incorporation of Ce ions. En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.201106070/abstract