Appl. Surf. Sci. 509, 144877 (2020) [pdf]

Corrosion Behavior of Diamond-like Carbon Film Induced by Al/Ti Co-doping

Xiaowei Su, Yong Zhou, Linlin Liu, Peng Guo, Xiaowei Li, Kwang-Ryeol Lee, Ping Cui, Aiying Wang
 

Diamond-like carbonfilms with Al and Ti dopants (Al/Ti-DLC) were fabricated by a hybrid ion beam depositionsystem combined with a special design of splicing targets, in which the Al/Ti ratio was changed from 4.0 to 1.1by tailoring the Al content. The structural evolution and corrosion behavior of Al/Ti-DLCfilms in 3.5 wt% NaClsolution were systematically investigated by comparing with the 316L SS and pure DLCfilm. Results revealedthat compared with the pure DLC and 316L SS substrate, the Al/Ti-DLCfilm exhibited enhanced corrosionresistance by reducing the porosity and increasing the barrier for both the charge transfer and the diffusion ofcorrosive ions into the substrate. In particular, the anti-corrosion behavior of DLCfilm highly depended on theAl/Ti ratio, which decreased gradually with the Al/Ti ratio ranged from 4.0 to 1.1. Structural and EIS analysisindicated that this was ascribed to both the increased residual stress and sp2hybridized fraction, which inducednot only the formation and propagation of cracks during the corrosion process but also the high electric con-ductivity and low diffusion barrier of corrosive ions, accelerating the corrosion processes at thefilm/substrateinterface.