Effect of titanium or chromium content on the electrochemical properties of amorphous carbon coatings in simulated body fluid

Amorphous carbon coatings (a-C) incorporated with various titanium and chromium content (Ti/a-C and Cr/a-C) were deposited on 316L substrates using unbalanced magnetron sputtering. The relevant electrochemical characteristics in simulated body fluid (SBF) indicated that Ti/a-C and Cr/a-C coatings could enhance the anticorrosion abilities of 316L substrates via increasing charge transfer resistant (Rct) due to formation of titanium and chromium oxides. However, the more Ti incorporation is likely to weaken the anticorrosion ability of Ti/a-C coatings due to more sp2 content. On the contrary, the more Cr incorporation can enhance the anticorrosion ability of Cr/a-C coatings owing to more sp3 content.