چکیده
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In the current investigation, direct current magnetron sputtering (DCMS) provided
nanostructured (NS) α-Ta coating on pure Ti substrate as an effective coating technique.
Microstructural observations revealed that a dense and homogeneous coating exhibiting (110)
preferred orientation could be achieved. Different electrochemical experiments were performed
to study the electrochemical and passive behaviors of α-Ta coating and uncoated commercially
pure Ta in the Ringer’s physiological electrolyte at 37 °C. Interestingly, the electrochemical
response and semiconducting behavior of α-Ta coating and pure Ta were different in several
aspects. α-Ta coating showed a superior passive behavior and higher level of protection in
Ringer’s physiological electrolyte at 37 °C compared to pure Ta. Mott–Schottky (M–S) analysis
clearly showed that a less defective passive film forms on α-Ta coating due to its lower levels of
donor densities compared to what could be estimated for the case of pure Ta. α-Ta coating
offered a considerably improved corrosion resistance in the aforementioned physiological
environment, owing to its nano-scale features that have facilitated the formation of less defective
and thicker protective passive films.
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