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Acidification of the electrolyte during the galvanic corrosion of AA7075: A numerical and experimental study
Author(s) -
Montoya Rodrigo,
RuizGarcía Allan G.,
OrtizOzuna Alma,
RamírezBarat Blanca,
Genesca Juan
Publication year - 2021
Publication title -
materials and corrosion
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.487
H-Index - 55
eISSN - 1521-4176
pISSN - 0947-5117
DOI - 10.1002/maco.202012274
Subject(s) - electrolyte , galvanic cell , electrochemistry , materials science , anode , alloy , corrosion , aluminium , metal , hydrolysis , chemical engineering , metallurgy , inorganic chemistry , chemistry , electrode , organic chemistry , engineering
The electrochemical interactions between aluminum alloy 7075 and low‐carbon steels under gelled electrolytes were studied. Such electrolytes provided the opportunity to investigate both thick and thin electrolyte systems. The electrolyte was chemically modified to visually track the acidic fronts during the anodic reaction and the subsequent hydrolysis process. Two mathematical models were validated for both thick and ultrathin electrolytes. The acidification of thick electrolytes was extended some millimeters beyond the aluminum alloy surface, whereas the acidic front was localized next to the metallic joint using ultrathin electrolytes. The combination of both numerical and experimental results allows proving (and explaining why) that the acidification process is more aggressive under dilute than under concentrated electrolytes.