Liu, Z., Shi, W., Xiang, S., Liu, F., & Ramamurty, U. (2024). Influence of OH− on the initiation and growth mechanism of pore structure during microarc oxidation of Ti-6Al-4 V alloy. Surface and Coatings Technology, 487, 130985. https://doi.org/10.1016/j.surfcoat.2024.130985
Abstract:
The presence of pores in a microarc oxidation (MAO) coating is an inherent characteristic that results from the expulsion and rapid solidification of molten material during the MAO process. The pore size in the MAO coating on the titanium alloy strongly affects the biocompatibility, but how to control it is unclear. The present study utilizes the advantages of NaOH to modulate pore size and plasma discharge, thereby effectively regulating the pore structure of the coating. The FIB-lift-out method was employed to directly extract the cross-sectional samples from the coating, enabling a detailed investigation of the pore microstructure using transmission electron microscopy (TEM). The structure surrounding the discharge channels exhibit layered zoning characteristics, with an amorphous layer near the discharge channel and a distinct crystal structure further away from it. The addition of NaOH enables the regulation of electrochemical and energy release processes, while also facilitating efficient discharge and spark generation to effectively disrupt the oxide layer and establish a plasma discharge channel.
License type:
Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)
Funding Info:
This research / project is supported by the Agency for Science, Technology and Research - Structural Metal Alloys Programme
Grant Reference no. : A18B1b0061