Corrosion performance of HVOF and APS thermally sprayed NiTi intermetallic coatings in 3.5% NaCl solution

Verdian, M. M.; Raeissi, K.; Salehi, Mehdi

doi:10.1016/j.corsci.2009.11.034

Cited by 123 publications

(57 citation statements)

References 45 publications

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“…The appearance of two time constants in impedance diagrams also indicates that part of the base NiTi is exposed to artificial saliva because of the presence of the defects in coating, as explained in detail previously. 30 Galvanic coupling of NiTi to noble metals or alloy leads to an increased corrosion rate of NiTi 31 because of differences in corrosion potential between noble materials gold and rhodium (representing the cathode site) and underlying nickel and titanium (representing the anodic site). In our case, the anodic area (ie, bare alloy on spots where small pores and cracks occurred in the noble coating) was quite smaller than the cathode area, which may lead to a significant galvanic effect.…”

Section: Discussionmentioning

confidence: 99%

Influence of surface layer on mechanical and corrosion properties of nickel-titanium orthodontic wires

Katić

Ćurković

Semenski

et al. 2014

The Angle Orthodontist

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To analyze the effect of various coating formulations on the mechanical and corrosion properties of nickel-titanium (NiTi) orthodontic wires. Materials and Methods: Uncoated, rhodium-coated, and nitrified NiTi wires were observed with a three-point-bend test, surface roughness (Ra) measurement, scanning electron microscopy, energy dispersive spectroscopy, and electrochemical testing (open circuit potential, electrochemical impedance spectroscopy, and cyclic polarization scan). Differences in the properties of tested wire types were analyzed with analysis of variance and Tukey post hoc test. Results: Uncoated and nitrified NiTi wires showed similar mechanical and anticorrosive properties, while rhodium-coated NiTi wires showed the highest Ra and significantly higher modulus of elasticity, yield strength, and delivery of forces during loading but not in unloading. Rhodium-coated NiTi wires also had the highest corrosion current density and corrosion potential, lowest impedance modulus, and two time constants on Bode plot, one related to the Rh/Au coating and the other to underlying NiTi. Conclusion: Working properties of NiTi wires were unaffected by various coatings in unloading. Nitrification improved corrosion resistance. Rhodium coating reduced corrosion resistance and pronounced susceptibility to pitting corrosion in artificial saliva because of galvanic coupling between the noble coating and the base alloy.

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Section: Discussionmentioning

confidence: 99%

Influence of surface layer on mechanical and corrosion properties of nickel-titanium orthodontic wires

Katić

Ćurković

Semenski

et al. 2014

The Angle Orthodontist

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“…1 [29]. In addition, the corrosion rate of the coating layer is accelerated because Al spray coating forms a galvanic cell with the SS400 which shows a nobler potential [30]. On the other hand, Al-3Mg coating layer showed that the corrosion current density is the lowest in spite of the greatest porosity in its coating layer.…”

Section: Resultsmentioning

confidence: 98%

Electrochemical Characteristics in Seawater for Cold Thermal Spray-Coated Al–Mg Alloy Layer

Park

Kim

2016

Acta Metall. Sin. (Engl. Lett.)

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For corrosion protection of carbon steel in a marine environment, cold arc thermal spray coating was applied to the surface with Al and Al-Mg alloy wires. The surface hardness of Al and Al-Mg thermal spray coatings increased with Mg content. And the various electrochemical experiments were carried out to evaluate corrosion damage characteristics of the thermal spray coating layers. The Al and Al-Mg thermal spray coating layers presented negative potentials compared to carbon steel in corrosion potential measurements. And an anodic polarization experiment revealed a tendency of activation polarization with no passivation. Furthermore, the corrosion damage of the thermal spray coating layer in galvanostatic experiment was observed mainly at the defect area, and the Al-3Mg thermal spray coating layer presented less surface damages than others. In addition, the Al-3Mg thermal spray coating layer showed the lowest corrosion rate while having a sufficient driving voltage for cathodic corrosion protection. Therefore, it is an optimal thermal spray material for sacrificial anode.

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“…In the plasma process, the particles reach speeds well below the speeds of the HVOF process, which in turn results in coatings with more regions of porosity and, thus, compromises their barrier effects. In other researches, the superiority of the HVOF process, concerning corrosion resistance, remained evident when compared to the plasma process, considering the smaller number of defects presented in the coating obtained by the HVOF technique [51].…”

Section: Potentiodynamic Polarizationmentioning

confidence: 99%

Corrosion behavior of nickel and cobalt coatings obtained by high‐velocity oxy‐fuel (HVOF) thermal spraying on API 5CT P110 steel

Brandolt

Ortega-Vega

Menezes

et al. 2015

Materials & Corrosion

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The API 5CT P110 steel is employed in oil and gas industry due to its excellent mechanical properties. However, its poor corrosion resistance makes necessary the employment of a protection. Although nickel-based and cobalt-based coatings obtained by HVOF have been widely studied regarding corrosion resistance, they are normally associated with other elements. Pure nickel and/or pure cobalt HVOFobtained coatings have not yet been studied.Therefore, in this work, the corrosion resistance of nickel and cobalt coatings obtained by high-velocity oxy-fuel thermal spraying on API 5CT P110 steel was evaluated. The coatings were characterized regarding morphology and structure by SEM, EDS, XRD, roughness, and Vickers microhardness. The corrosion resistance was evaluated by OCP monitoring and potentiodynamic polarization in a 3.5 wt% sodium chloride solution. The results showed that both coatings acted as a barrier and avoided the contact between the steel substrate and the electrolyte due to the low melting point of the metals employed, which resulted in effective fusion of the particles. Besides, the nickel coating, promoted a better corrosion resistance compared to cobalt coating.

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Corrosion performance of HVOF and APS thermally sprayed NiTi intermetallic coatings in 3.5% NaCl solution

Cited by 123 publications

References 45 publications

Influence of surface layer on mechanical and corrosion properties of nickel-titanium orthodontic wires

Influence of surface layer on mechanical and corrosion properties of nickel-titanium orthodontic wires

Electrochemical Characteristics in Seawater for Cold Thermal Spray-Coated Al–Mg Alloy Layer

Corrosion behavior of nickel and cobalt coatings obtained by high‐velocity oxy‐fuel (HVOF) thermal spraying on API 5CT P110 steel

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