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Electrochemical corrosion behavior of micrometer‐sized porous Ti 3 SiC 2 compounds in NaCl solution
Author(s) -
Jiang Yao,
He Yuehui
Publication year - 2020
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.201911051
Subject(s) - passivation , materials science , corrosion , porosity , electrochemistry , open circuit voltage , ohmic contact , composite material , layer (electronics) , chemical engineering , capacitance , metallurgy , electrode , chemistry , physics , voltage , quantum mechanics , engineering
The electrochemical corrosion behavior of reactively synthesized porous Ti 3 SiC 2 in 1 M NaCl solution was investigated compared with that of porous TiAl. Porous Ti 3 SiC 2 and TiAl have high‐purity single phase characteristics with open porosities of 48% and 41% and maximum apertures of 6.9 and 16.3 µm, respectively, which show positive direction shift behavior of open circuit potential at the early immersion stage with stable potential ranges of 0.25~0.27 and −0.36~−0.38 V (vs. saturated calomel), respectively. The electrochemical corrosion procedures of the two porous compounds exhibit three‐stage characteristics of activation, passivation, and breakdown. Porous Ti 3 SiC 2 has a much larger ohmic resistance and Warburg coefficient than TiAl. The passivation films of the two porous compounds consist of an inner layer with a larger resistance and a porous outer layer. Porous Ti 3 SiC 2 has a significantly larger resistance and relatively smaller capacitance for the inner passivation film, indicating better corrosion resistance stability.