Evaluation of Corrosion Resistance of Commercial Aluminum Alloys in Ethanol Solutions

Abstract

In the present research, we studied the corrosion resistance of commercial aluminum alloys exposed to ethanol produced in the northeastern region of Argentina and to commercial ethanol as reference medium. Electrochemical tests of potentiodynamic polarization and weight loss were performed by immersion at temperatures below the boiling point of ethanol (25 °C, 40 °C and 50 °C). The results showed that the increase in the corrosion rate of the alloys is directly proportional to the increase in the temperature of the solution, and that the combined action of contaminants in the alcohol (water, organic acids or aggressive ions) contributed to the increase in the aggressiveness of the environment. Specifically, through the results of the gravimetric tests, corrosion products characteristic of the formation of pitting corrosion and alkoxidation were observed. In contrast to the above, the existence of the pitting corrosion mechanism was demonstrated by defining a pitting potential in the potentiodynamic polarization curves.

Evaluation of the influence of alumina nano-particle size and weight composition on the corrosion resistance of monolithic AA1070 aluminium

“…The corrosion rate value is representative of general surface deterioration. However, the anodic slope configuration shows sample B1 and B2 exhibits relatively weak resistance to anodic dissolution and pitting corrosion which is a major destructive mechanism on composites [26]. Decrease in corrosion potential data from À0.756 V to À0.879 V in Table 4 from sample A to B4 confirms the effect of localized deterioration on the matrix samples.…”

Evaluation of innovative microreactor for examination of alkoxide pitting corrosion and data generation for numerical transient model

“…This kind of chemical 'dry corrosion' takes place in alcohols with low water content at temperatures above 80 °C mostly in form of circular corrosion pits and the corrosion reaction is particularly rapid capable of causing component failures in few minutes. Moreover, alcoholate corrosion, due to low electrical conductivity of electrolyte (ethanol), is believed to be a predominantly chemical kind of reaction, which highly depends on physical, chemical and physico-chemical factors such as: water content, temperature, presence of certain alloying elements in aluminium, ethanol impurities and the (metallic) surface condition [10][11][12][13][14][15]. Equations (1)(2)(3) give an overview on the involved reactions [16]:…”

“…This kind of chemical ‘dry corrosion’ takes place in alcohols with low water content at temperatures above 80 °C mostly in form of circular corrosion pits and the corrosion reaction is particularly rapid capable of causing component failures in few minutes. Moreover, alcoholate corrosion, due to low electrical conductivity of electrolyte (ethanol), is believed to be a predominantly chemical kind of reaction, which highly depends on physical, chemical and physico‐chemical factors such as: water content, temperature, presence of certain alloying elements in aluminium, ethanol impurities and the (metallic) surface condition [10–15]. Equations (1–3) give an overview on the involved reactions [16]: $$$\vcenter{\openup.5em\halign{$\displaystyle{#}$\cr 3{\rm \ }{{\rm C}}_{2}{{\rm H}}_{5}{\rm O}{\rm H}+{\rm A}{\rm l}\to {\rm A}{\rm l}{\left({{\rm C}}_{2}{{\rm H}}_{5}{\rm O}\right)}_{3}+{{3}\over{2}}{{\rm H}}_{2}\hfill\cr}}$$$ $$$\vcenter{\openup.5em\halign{$\displaystyle{#}$\cr {\rm A}{\rm l}{\left({{\rm C}}_{2}{{\rm H}}_{5}{\rm O}\right)}_{3}+3{\rm \ }{{\rm H}}_{2}{\rm O}\to {\rm A}{\rm l}{\left({\rm O}{\rm H}\right)}_{3}+3{\rm \ }{{\rm C}}_{2}{{\rm H}}_{5}{\rm O}{\rm H}\hfill\cr}}$$$ …”

Packaging of Wine in Aluminum Cans – A Review

“…Although the corrosion potential of Al alloys declines as the chloride ion content in the medium rises, the corrosion current density remains almost constant at pH 3.0 up to a chloride content of 1000 mg/kg (Soares et al 2017). Once chloride penetrates the passivation Al 2 O 3 layer, the pitting corrosion process is triggered (Kramer et al 2018). The result of this reaction is the dissolution of Al into the wine (Figure 1).…”