Aluminum corrosion

Aluminum containers are recommended for many appHcations because of the very hard, corrosion-resistant oxide coating. They are deficient in only one respect once the protective skin has been penetrated, aluminum corrosion accelerates. 

Zinc is attacked at high pH. However, in weakly alkaline solutions near room temperature, corrosion is actually very slight, being less than 1 mil/y (0.0254 mm/y) at a pH of 12. The corrosion rate increases rapidly at higher pH, approaching 70 mil/y (1.8 mm/y) at a pH near 14. Just as in aluminum corrosion, protection is due primarily to a stable oxide film that forms spontaneously on exposure to water. High alkalinity dissolves the oxide film, leading to rapid attack. 

Aluminum and stainless steel are used almost interchangeably for any strength of nitric acid. Figure 3.7 compares the rate of attack of cold nitric acid on stainless steel and aluminum. Figure 3.7 shows that higher rates of aluminum corrosion occur up to about 80% nitric acid (HNO3), but aluminum is still to be preferred over stainless steel for any concentration above 80%. 

Fumeaux, R. C., G. E. Thompson and G. C. Wood. 1978. The application of ultramicrotomy to the electronoptical examination of surface films on aluminum. Corrosion Science 18 853-81. 

In most corrosion processes passivity is desirable because the rate of electrode dissolution is significantly reduced. The rate of aluminum corrosion in fresh water is relatively low because of the adherent oxide film that forms on the metal surface. A thicker film can be formed on the surface by subjecting it to an anodic current in a process known as anodizing. In most electrochemical conversion processes passive films reduce the reaction rate and are, therefore, undesirable. 

Figure 7.28 Aluminum corrosion products on the interior surface of a dress-cap. (Reproduced from COM 1999 and 2005 with permission from the Metallurgy Society of CIM)...

Hydrochloric add Nitric add Dissolves most water scales and corrosion products Dissolves most water scales and corrosion products On boilers, heat exchangers, pipelines, etc. On stainless steel and aluminum Corrosive to steel temperature must be below 175T Cannot be used on copper and ferrous alloys... 

Kinetics of Oxide-Covered Aluminum, Corrosion, Vol 19, 1963, p 403t-407t... 

CHEMICAL PROPERTIES nonflammable gas extremely stable to heat, even up to 2000°C reacts with water to form sulfurous acid (H2SO3) catalytically oxidized by air to sulfur trioxide (SOj) will slowly oxidize from sulfurous to sulfuric acid reacts with alkaline materials such as sodium and potassium reacts with some active metals like aluminum, brass, copper, and zinc may corrode aluminum corrosive when dissolved in water as sulfurous acid FP (NA) LFL/UFL (NA) AT (NA) HC (NA) HF (-320 kJ/mol liquid at 25°C, -296.8 kJ/mol gas at 25°C). 

Figure 5.28 Aluminum corrosion products on interior surface of dress cap. (Figure originally published in Reference 26. Reproduced with permission of the Canadian Institute of Mining, Metallurgy and Petroleum, www.cim.org.)...

The shape of the 1910 canteen also became the standard that is still represented by today s molded polyethylene 1-quart (0.95-1) canteen, NSN 8465-00-889-3744 (Fig. 14.3). The 1910 1-qnart shape went through material changes thronghout its life cycle. Aluminum, corrosion-resistant steel, plastic and porcelain were used at different periods of the canteen s history. During World War II, aluminum was... 

H. Yang, K. Kwon, T. M. Devine, J. W. Evans, J. Electrochem. Soc. 2000, 147, 4399-4407. Aluminum corrosion in lithium batteries. An investigation using the electrochemical quartz crystal microbalance. 

A. Abouimrane, J. Ding, 1. J. Davidson, J. Power Sources 2009, 189, 693-696. Liquid electrolyte based on lithium bis-fluorosulfonyl imide salt Aluminum corrosion studies and lithium ion battery investigations. 

H. Xie, Z. Tang, Z. Li, Y. He, H. Wang, Y. Liu, Electrochem. Solid-State Lett. 2008,11, C19-C22. Aluminum corrosion behavior of LiBOB in composite polymer electrolyte for Li-polymer batteries. 

D. Moosbauer, S. Zugmann, M. AmereUer, H. J. Gores, J. Chem. Eng. Data 2010, 55, 1794-1798. Effect of ionic liquids as additives on lithium electrolytes Conductivity, electrochemical stability, and aluminum corrosion. 

Cohen, S.M. 1995. Replacements for chromium pretreatments on aluminum. Corrosion (Houston)... 

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