The initial interaction of water vapour with MgAl alloy surfaces at room temperature

Splinter, S.J.; McIntyre, N. S.

doi:10.1016/0039-6028(94)90003-5

Cited by 61 publications

(37 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…These results show some similarity to those observed by Splinter and McIntyre [46] , who found that the rate of oxide nucleation and growth is enhanced on Mg-Al surfaces compared to pure Mg surfaces, especially at higher Al contents. Furthermore, the thickness of the native oxide film on the AZ80 alloy is greater than that observed on the AZ91D alloy ( Table 3).…”

Section: Xps Analysis Of the Spontaneously Formed Native Oxide Film Osupporting

confidence: 78%

“…Many researchers have carried out studies to establish relationships between the alloy microstructure (amount and distribution of phase in alloys) or the Al content in the bulk alloy and its corrosion resistance . Far fewer studies have addressed aspects related with the chemical composition of the thin native oxide films that form on the outer surface (thicknesses of the order of 3 nm) in contact with the atmosphere or with solutions of low aggressivity [35][36][37][38][39][40][41][42][43][44][45][46]. Differences in the thickness and chemical composition of these films, as a function of the alloy microstructure and alloying element composition, can yield basic information about their formation on Mg-Al alloys in the atmosphere or during immersion in saline solutions.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Native Air-Formed Oxide Film and its Effect on Magnesium Alloys Corrosion

Galván¹

2010

TOCORRJ

View full text Add to dashboard Cite

Abstract:The present work uses X-ray photoelectron spectroscopy (XPS) analysis to compare the chemical composition of native oxide films formed spontaneously on commercial pure magnesium and AZ31, AZ80 and AZ91D magnesium alloys. The study considers both the outer surface and inner regions of the films with the assistance of argon ion bombardment. Possible relationships are established between the alloy Al content and the native oxide film characteristics. The Al content is very similar in the oxide films on all three studied alloys. XPS identifies a much greater film thickness on AZ80 and AZ91D specimens than on AZ31 and pure Mg specimens, which seems to be related with the presence of phase (Mg 17 Al 12 ) on the AZ91D alloy surface and of the eutectic -Mg/ on the AZ80 alloy surface. Considerable Ca segregation is observed (directly related with the calcium impurities content in the bulk material) towards the outer surface of the metal, where it appears in the form of calcium oxide. Direct correspondence is found between the thickness of the native oxide film formed spontaneously on the surface of magnesium and its alloys and their subsequent corrosion resistance in exposure to a 3.5 wt% NaCl solution.

show abstract

Section: Xps Analysis Of the Spontaneously Formed Native Oxide Film Osupporting

confidence: 78%

Section: Introductionmentioning

confidence: 99%

Native Air-Formed Oxide Film and its Effect on Magnesium Alloys Corrosion

Galván¹

2010

TOCORRJ

View full text Add to dashboard Cite

show abstract

“…The effect of aluminium as an alloying element to improve the corrosion resistance of magnesium has been studied in a wide range of experimental conditions, such as exposure to dry oxygen [1,2], ambient atmospheres [3][4][5], atmospheres with a high degree of humidity [6][7][8][9][10], in immersion in distilled water [11], in saline solutions or atmospheres [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27], etc. In Mg-Al alloys the greater oxygen affinity of aluminium tends to produce passivating aluminium oxide films or mixtures of Mg and Al oxides, which make the exposed surface especially stable [14][15][16][17].…”

Section: Introductionmentioning

confidence: 99%

Effect of naturally formed oxide films and other variables in the early stages of Mg-alloy corrosion in NaCl solution

Feliú

Maffiotte

Samaniego

et al. 2011

Electrochimica Acta

View full text Add to dashboard Cite

“…[16][17][18][19][20][21][22][23] However, what is lacking is a detailed nano/micro structural level picture of the film nature and alloy/film interface regions, particularly with regards to segregation of alloying additions and film evolution with time. There have been relatively few studies of Mg alloy corrosion utilizing cross-section transmission electron microscopy (TEM) analysis to better elucidate the nature of the films formed, the work of Nordlien et al in the 1990's the primary exception.…”

mentioning

confidence: 99%

Transmission Electron Microscopy Study of Aqueous Film Formation and Evolution on Magnesium Alloys

Unocic

Elsentriecy

Brady

et al. 2014

J. Electrochem. Soc.

127

126

View full text Add to dashboard Cite

The films formed on ultrahigh purity Mg, Elektron 717 (ZE10A), and AZ31B in water at room temperature were characterized by TEM, XPS, and SIMS. The films consisted primarily of MgO, with surface regions also containing Mg(OH) 2 and MgCO 3 . SIMS suggested H throughout the films and into the underlying metal. Segregation of Zn to the metal/film interface and Al in the film was observed for AZ31B. Similar Zn film segregation was also detected for Elektron 717, along with Nd at the alloy/film interface and nano-size Zn 2 Zr 3 precipitates throughout the film. Implications of these findings on film growth are discussed. Magnesium and its alloys are lightweight structural materials of great interest for reduced vehicle weight and improved fuel efficiency in the automotive industry due to their good strength, low density, amenability to casting, and ease of recycling.1-3 A major drawback, however, is the poor corrosion resistance of Mg under many conditions. 4 Magnesium is considered the most reactive structural material and is susceptible to multiple forms of corrosion; including general dissolution, galvanic coupling, localized corrosion, and stress corrosion cracking. 2,3,5,6 Surface treatments/coatings are needed for many applications which result in increased cost and can be a source of component durability issues. 1The inability of Mg alloys to establish a continuous and fully protective surface film under many exposure conditions is a key factor underlying their susceptibility to corrosive attack. Films formed on Mg alloys under humid air or aqueous corrosion conditions are typically based on mixtures of MgO and Mg(OH) 2 .4,7-12 Although MgO can offer a degree of protection under ambient dry atmospheric corrosion conditions, it can be readily hydrated in the presence of water or water vapor to form Mg(OH) 2 , which offers limited stability and reduced protectiveness. 4 Further, considerations based on Pilling-Bedworth (P-B) ratio have also been invoked for explaining the inability of Mg to establish a fully protective oxide film. 13 Magnesium has a P-B ratio of ∼0.8, which places surface MgO in tension, and can result in a porous, cracked, nonprotective oxide layer. (Typically a P-B ratio of 1-2 is considered a minimum, but not sufficient prerequisite for protective film formation). Corrosion can be further significantly accelerated when aggressive electrolyte species such as chloride are present. 5,14 Alloying has been shown to modify surface film performance; 15 however, a detailed mechanistic understanding of how and why is frequently lacking.Extensive studies based on electrochemical assessment and surface film chemistry depth profiling of Mg alloys have been pursued by techniques such as Auger electron spectroscopy (AES), secondary ion mass spectroscopy (SIMS), X-ray photoelectron spectroscopy (XPS), etc. [16][17][18][19][20][21][22][23] However, what is lacking is a detailed nano/micro structural level picture of the film nature and alloy/film interface regions, particularly with regards to segregation of...

show abstract

The initial interaction of water vapour with MgAl alloy surfaces at room temperature

Cited by 61 publications

References 30 publications

Native Air-Formed Oxide Film and its Effect on Magnesium Alloys Corrosion

Native Air-Formed Oxide Film and its Effect on Magnesium Alloys Corrosion

Effect of naturally formed oxide films and other variables in the early stages of Mg-alloy corrosion in NaCl solution

Transmission Electron Microscopy Study of Aqueous Film Formation and Evolution on Magnesium Alloys

Contact Info

Product

Resources

About