Electrochemical Characterization of Certain Mg-Based Alloys in Artificial Perspiration Biofluid for Consumer and Industrial Applications

The weight reduction of numerous consumer electronic devices is of increasing importance. In this respect, ultra-light magnesium alloys have attracted more attention to be used as frame materials. Nevertheless, Mg alloys are of intrinsically poor corrosion resistance, especially in chloride ion-containing environments. Human perspiration fluid with a relatively high chloride ions content (similar to 0.14 M) comes in contact with a number of consumer products resulting in a variety of undesirable effects such as malfunction and corrosion. Based on that, the present work addresses the corrosion behavior of five AZ-Mg alloys including AZ91D, AZ80E, AZ31, AM60 and AXJ530 in artificial perspiration biofluid at human body temperature of 37 degrees C. The study is performed using electrochemical impedance spectroscopy and potentiodynamic polarization techniques supported by surface morphological and EDX spectra examinations. The surface layer total resistance value (R-T) estimated from the analysis of obtained impedance data after 12-h exposure period reveals that durability of our tested samples increases in the following sequence: AZ80 > AZ91 > AZ31 > AM60 > AXJ530 > Mg (control). AZ80E alloy at top of this sequence points to its significantly high anti-corrosion performance in artificial perspiration biofluid and thus can be the best Mg materials of choice for many housing consumer electronic products. This outcome is in consistence with the corrosion rate (Pi in mm y(-1)) trend as derived from the potentiodynamic polarization data that decreases in the following order: AZ80 (0.25) < AZ91 (0.49) < AZ31 (1.03) < AM60 (1.23) < AXJ530 (5.36) < Mg (5.98). Both FE-SEM images and EDX analyses further confirm these experimentally electrochemical findings.