scholarly journals Influencia del tipo de sinterizado en el comportamiento anticorrosivo de recubrimientos sol-gel

Respuestas ◽  
2016 ◽  
Vol 13 (2) ◽  
pp. 5-10
Author(s):  
Jorge Hernando Bautista-Ruiz ◽  
César Armando Ortiz-Otálora ◽  
Enrique Vera-Lopez

Este trabajo muestra un estudio electroquímico de recubrimientos SiO2 TiO2 ZrO2 obtenidos por el método sol-gel, sinterizados vía plasma y vía convencional. Los recubrimientos se conformaron a partir de Si(OC2H5)4, Ti(OBu)4 y Zr(OC3H7)4, se depositaron sobre sustratos de acero ANSI/304 mediante dip-coating en monocapa y bicapa. El proceso de densificado vía plasma se realizó a temperaturas del sustrato de 250 ºC, 300 ºC y 330 ºC y el convencional a 400 ºC y a una velocidad de calentamiento de 2 ºC/min. El comportamiento anticorrosivo se estudió mediante las técnicas de espectroscopía de impedancia electroquímica (EIS) y Tafel. Se observó que el proceso de sinterización vía plasma, mejora la resistencia a la corrosión con respecto al método convencional.Palabras Clave: sol-gel; corrosión; plasma; EIS;Tafel Abstract This work shows a comparative electrochemical study among the anticorrosive properties of coatings SiO2 TiO2 ZrO2 obtained by the method sol-gel and plasma sintering process and conventional. The coatings conformed to starting from Si(OC2 H5 )4 , Ti(OBu)4 and Zr(OC3 H7 )4 . These were deposited on steel substrate 304 by means of dip-coating in mono-layer and bi-layer. The plasma sintering process was carried out to temperatures of the substrate of 250 ºC, 300 ºC and 330 ºC and the conventional to 400 ºC and a speed of heating of 2 ºC/min. the anticorrosive behavior was studied by means of the techniques of electrochemical impedance spectroscopy (EIS) and Tafel. It was observed that the plasma sintering process, it improves the resistance to the corrosive attack to in regard to the conventional method.Keywords: sol-gel, corrosion, plasma, EIS, Tafel

2017 ◽  
Vol 64 (4) ◽  
pp. 365-370 ◽  
Author(s):  
Sebahattin Kirtay

Purpose The purpose of this paper is to investigate the corrosion resistance of SiO2-Al2O3 coating on mild steel. Design/methodology/approach SiO2-Al2O3 was coated using sol-gel method, and electrochemical measurements were applied to assess the performance of the coated steel. Findings The main conclusion is that SiO2-Al2O3-coated specimens acquired a higher corrosion resistance than that of uncoated specimen. icorr values of the coated specimens were between 12 and 14 times smaller than those of uncoated specimen. The coated specimens exhibited a higher Rcor value at electrochemical impedance spectroscopy analysis. The high values of Rcor and low values of CPEdl observed within the SiO2-Al2O3-coated samples imply an improved anti-corrosion capability. Originality/value In this work, there are three points of originality. First, steel specimens were coated with ormosil-based solution by applying sol-gel dip coating method. Second, both SiO2 and Al2O3 coatings were applied simultaneously at a considerably low temperature, i.e. 200 °C. Finally, the performance of the coated materials against wet corrosion was improved significantly.


2015 ◽  
Vol 227 ◽  
pp. 515-518 ◽  
Author(s):  
Luigi Calabrese ◽  
Lucio Bonaccorsi ◽  
Chiara Borsellino ◽  
Angela Caprì ◽  
Francesca Fabiano ◽  
...  

In this work the assessment of the corrosion performances in saliva solution of NdFeB magnets coated with silane layers was studied for its application in orthodontic brackets. The silane film, deposited by dip coating technique, has been prepared with varying dipping steps, with the purpose to identify the number of layers able to achieve an optimal protective action. Corrosion protection performance, during immersion in Fusayama synthetic saliva solution, was evaluated by means electrochemical impedance spectroscopy (EIS). The silane coatings evidenced good barrier properties resulting in an improvement of the anti-corrosion performances of the magnets. Better results were observed for samples with at least 15 layers of silane, that evidenced still acceptable protective action after three days of immersion in a Fusayama synthetic saliva solution.


2018 ◽  
Vol 18 ◽  
pp. 19-26
Author(s):  
Nadjette Belhamra ◽  
Abd Raouf Boulebtina ◽  
Khadidja Belassadi ◽  
Abdelouahed Chala ◽  
Malika Diafi

The purpose of this paper was to investigate the effect of Al2O3 and TiO2 nanoparticles contents on structural proporties, microhardness and corrosion resistance of Zn-Ni alloy coationg. Zn-Ni, Zn-Ni-Al2O3 and Zn-Ni-TiO2 composite coatings were electrodeposited on steel substrate by direct current in sulphate bath.The structure of the coatings was studied by X-ray diffration and by scaning electron miroscopy. The results showed the appearance of Ni5Zn21 phases and that the incrorporation of Al2O3 and TiO2 in the Zn-Ni coating refined the crystal grain size.The corrosion performance of coating in the 0.6M NaCl as a corrisive solution was investigated by potentiodynamic polarization and electrochemical impedance spectroscopy EIS methods. It was found that the incorporation of nanoparticules in Zn-Ni alloy coating have better corrosion resistance and the values of Rct and Zw increase, while the values of Cdl decrease with increasing of nanoparticules.


Coatings ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 783 ◽  
Author(s):  
Muna Ibrahim ◽  
Karthik Kannan ◽  
Hemalatha Parangusan ◽  
Shady Eldeib ◽  
Omar Shehata ◽  
...  

ZnO-NiO nanocomposite with epoxy coating on mild steel has been fabricated by the sol–gel assisted method. The synthesized sample was used to study corrosion protection. The analysis was performed by electrochemical impedance spectroscopy in 3.5% NaCl solution. The structural and morphological characterization of the metal oxide nanocomposite was carried out using XRD and SEM with Energy Dispersive Absorption X-ray (EDAX) analysis. XRD reveals the ZnO-NiO (hexagonal and cubic) structure with an average ZnO-NiO crystallite size of 26 nm. SEM/EDAX analysis of the ZnO-NiO nanocomposite confirms that the chemical composition of the samples consists of: Zn (8.96 ± 0.11 wt.%), Ni (10.53 ± 0.19 wt.%) and O (80.51 ± 3.12 wt.%). Electrochemical Impedance Spectroscopy (EIS) authenticated that the corrosion resistance has improved for the nanocomposites of ZnO-NiO coated along with epoxy on steel in comparison to that of the pure epoxy-coated steel.


ACS Omega ◽  
2018 ◽  
Vol 3 (6) ◽  
pp. 6880-6887
Author(s):  
Joshua Whittam ◽  
Andrew L. Hector ◽  
Christopher Kavanagh ◽  
John R. Owen ◽  
Gillian Reid

2011 ◽  
Vol 418-420 ◽  
pp. 1869-1872
Author(s):  
Maziidah Hamidi ◽  
Syafawati Nadiah Mohamed ◽  
Muhd Zu Azhan Yahya

The Li-ion fast conductor, Li1-XAlxTi2-X(PO4)3 (LATP) compound were synthesized by a sol-gel method. Effects due to the addition of Al3+ into Li1-XAlxTi2-X(PO4)3 (x=0.0-0.5) glass-ceramics system have been investigated using electrochemical impedance spectroscopy (EIS), X-ray differential analysis (XRD) and permittivity studies. The crystalline phase of the samples obtained confirming that they had a characteristic of glass-ceramics structure.


2016 ◽  
Vol 869 ◽  
pp. 680-684
Author(s):  
Ana Paula Jardim Roquete ◽  
Valeska Rodrigues Roque ◽  
Laura Martins Fonseca ◽  
Lorena Aparecida Nunes Viana ◽  
Angélica Karine Henkes ◽  
...  

The capacitive properties on aluminum alloy coated by sol-gel are evaluated in this work. The samples were anodized in a H2SO4 solution for three different times (15, 20 and 30 min) and subsequently covered by a sol-gel. The capacitance of the samples was evaluated by electrochemical impedance spectroscopy (EIS). Firstly the capacitance of the anodizing samples was evaluated. The second condition was the evaluation of the anodized samples coated by sol-gel. The better capacitance results obtained in the first condition was observed in the blank samples and by the 15 min anodized samples. After the sol-gel deposition, the influence of coating on the overall capacitance was observed. Their stability during the immersion time of the evaluation was observed as well.


2016 ◽  
Vol 89 (4) ◽  
pp. 712-723 ◽  
Author(s):  
I. Ismail ◽  
M. K. Harun

ABSTRACT Chemlok 205 primer is a common bonding agent used together with a top coat in rubber/metal–bonded composites. Recent studies indicated that a stand-alone Chemlok 205 primer failed when its metal substrate underwent corrosion. The failure was suspected to be caused by coating degradation, followed by cathodic disbonding, induced from the corrosion reaction. Therefore, in this work, the effect of cathodic polarization on the coating delamination was further investigated. The work intends to focus on understanding the adhesion failure processes involved. Thus, electrochemical impedance spectroscopy (EIS) was employed on a stand-alone industrial coating Chemlok 205 primer on mild steel substrate subjected to cathodic polarization potential of −0.8 V versus Ag/AgCl reference electrode in 0.5 M NaCl. The coating barrier properties were interpreted through Nyquist and Bode plots of the EIS plots for a selected time interval. The data obtained were modeled against three distinguished electrical equivalent circuits representing the stages of coating degradation against time. Analysis through Nyquist and Bode plots indicated that the stand-alone Chemlok 205 primer coating experienced a significant drop in coating impedance before experiencing adhesion loss. The changes in the coating capacitance and coating resistance indicated that the coating underwent degradation first before adhesion failure.


2011 ◽  
Vol 415-417 ◽  
pp. 174-177
Author(s):  
Yu Qiu Huo ◽  
Ling Bai

Manganese ions doped Pani films were prepared by using a cyclic voltammetry technique on mild steel substrate. Corrosion resistances performances of them in 0.5 M H2SO4 solution were obtained by using electrochemical impedance spectroscopy (EIS), polarization curve, and SEM method. The results showed that manganese ions doped Pani particles became smaller and tighter, the resistance reduced, and the corrosion potential rose than Pani in H2SO4 solution.


Sign in / Sign up

Export Citation Format

Share Document