Deposition and corrosion resistance of HVOF sprayed nanocrystalline iron aluminide coatings

Ji, Gang; Elkedim, O.; Grosdidier, Thierry

doi:10.1016/j.surfcoat.2004.04.091

Cited by 77 publications

(39 citation statements)

References 36 publications

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“…Ji et al [134] have compared the corrosion behavior of nanocrystalline high-velocity oxy-fuel (HVOF) FeAl coatings with that of extruded Fe-Al alloy ( Figure 10). Though both HVOF coatings and extruded alloy showed similar active-passive and transpassive behavior, with the passive region consisting of two domains, the higher i corr and i pass for the HVOF coatings suggested their inferior corrosion resistance.…”

Section: B Fe-based Alloy Systemsmentioning

confidence: 99%

Role of Nanostructure in Electrochemical Corrosion and High Temperature Oxidation: A Review

Mahesh

Raman

2014

Metall Mater Trans A

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The extremely fine grain size of nanocrystalline (nc) metallic alloys results in significantly different mechanical, electrochemical and oxidation properties as compared to the coarse-grained alloys of the same composition. Although the synthesis and attractive mechanical properties of nanocrystalline materials have been investigated and reviewed in great depth, the high temperature oxidation and electrochemical corrosion of these materials has received limited attention. The difference in the active dissolution and passivation behavior of nc alloys as compared to their microcrystalline counterparts varies for each alloy system. However, a unified theory explaining these phenomena still eludes us. In this context, this article reviews the progress in the electrochemical corrosion behavior of different nanocrystalline alloys, and hence, develops a better understanding of the effect of grain size, composition, interfacial phenomena and selective dissolution on corrosion of nanocrystalline alloys. This review also presents the role of nanometric grain size and the associated increase in grain boundary diffusion on the high temperature oxidation of nc alloys. The attractive possibility of enhanced oxidation resistance at lower alloying additions as compared to the coarse-grained alloys has been discussed. Although the primary focus of the article is on ferrous alloy systems, however, the lead studies on the role of ultrafine grain size in oxidation/corrosion behavior of other alloys systems have also been reviewed.

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Section: B Fe-based Alloy Systemsmentioning

confidence: 99%

Role of Nanostructure in Electrochemical Corrosion and High Temperature Oxidation: A Review

Mahesh

Raman

2014

Metall Mater Trans A

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“…The big pores located between flattened droplets are mainly caused by the loose packed layer structure or gas porosity phenomenon, while the small pores within the flattened particles originate from the shrinkage porosity (Totemeier, 2005). Obviously, the porosity of the coatings reduces in the order of HVOF-G3, G2, and G1, and it is believed that increasing the fuel/oxygen ratio, increases both the thermal and kinetic energy of the gas flow, so that the majority of the powder particles are better melted and also accelerated to higher velocities www.intechopen.com and deformed extensively on impact to form elongated lamella (Ji, 2005). Some unmelted particles are clearly visible in HVOF-G3 (Fig.…”

Section: Amorphous (Hvof-g1)mentioning

confidence: 99%

A Solid State Approach to Synthesis Advanced Nanomaterials for Thermal Spray Applications

Movahedi¹

2012

Advanced Plasma Spray Applications

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“…Gang et al [34] compared the potentiodynamic polarization curves of the nanocrystalline high-velocity oxy-fuel (HVOF) FeAl coatings with that of a massive FeAl sample obtained by extrusion of the same milled powders (Figure 7.11). All curves exhibited a typical active-passive-transpassive behavior as the potential increased, with all curves also showing a passive region consisting of two domains.…”

Section: Electrochemical Corrosion Behavior Of Nanocrystalline Materialsmentioning

confidence: 99%

Electrochemical Corrosion Behaviour of Nanocrystalline Materials

Elkedim

2008

Nanostructured Materials in Electrochemistry

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Nanocrystalline materials have received much attention as a result of their unique physical, chemical and mechanical properties, and have been the subjects of intensive research activities both in the scientific and industrial communities.Nanocrystalline materials -that is, single or multiphase polycrystalline solids with a characteristic grain size of a few nanometers -represent a promising class of new materials. Owing to the extremely small crystallite dimensions (typically 1 to 100 nm), they are characterized structurally by a large volume fraction of interfaces which may lead to improvements in a variety of properties [1].Current spending on corrosion-related problems accounts for more than 3% of the worlds gross domestic product (GDP), and characterization of the corrosion behavior of nanocrystalline materials is important both for prospective engineering applications and for a better understanding of the above fundamental physicochemical properties [2,3]. In many cases the industrial application of novel materials will ultimately depend on their corrosion resistance over extended periods of service. For this reason, corrosion problems must be considered at an appropriate stage of material development.A limited number of investigations have concentrated on the corrosion of nanocrystalline materials. Rofagha et al. [4,5] studied nanocrystalline Ni and Ni-P produced by an electrodeposition technique, whereupon the observed behaviour was considered to be consistent with substantial contributions to the bulk electrochemical behavior from the intercrystalline regions (i.e., grain boundaries and triple junctions) of these materials.Inturi and Szklarska-Smialowska [6] have observed improved localized corrosion resistance in HCl for sputter-deposited nanocrystalline type 304 stainless steel in comparison with conventional material, and attributed this to the fine grain size and homogeneity of the nanocrystalline materials. Thorpe et al. [7] studied the corrosion behavior of nanocrystalline Fe 32 Ni 36 Cr 14 P 12 B 6 alloy obtained by crystallization of the melt-spun amorphous ribbon. These authors determined that the corrosion resistance of this material was significantly greater than that of its amorphous counterpart, and attributed the improvement to the observed greater Cr enrichment of the electrochemical surface via rapid interphase boundary diffusion [8].It is difficult to predict the electrochemical behavior of nanocrystalline materials from the known properties of their coarse-grained polycrystalline analogues. Thus, several groups have observed that nanocrystalline materials exhibit enhanced oxidation and corrosion resistance compared to their conventional microcrystalline counterparts [9][10][11][12]. In contrast, results obtained in other studies have shown nanocrystalline materials to have higher rates of dissolution and corrosion [13,14].The aim of this chapter is to outline the aqueous corrosion research activities currently being undertaken on nanocrystalline materials, with key results being extrac...

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Deposition and corrosion resistance of HVOF sprayed nanocrystalline iron aluminide coatings

Cited by 77 publications

References 36 publications

Role of Nanostructure in Electrochemical Corrosion and High Temperature Oxidation: A Review

Role of Nanostructure in Electrochemical Corrosion and High Temperature Oxidation: A Review

A Solid State Approach to Synthesis Advanced Nanomaterials for Thermal Spray Applications

Electrochemical Corrosion Behaviour of Nanocrystalline Materials

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