Tribocorrosion and corrosion behavior of double borided layers formed on Ti-6Al-4V alloy: An approach for applications to bio-implants

TiB2 and TiB double layers were formed on surface of Ti-6Al-4V by a diffusional process at 850 ͦC for 4–16 h. EIS and XPS analyses revealed that formation of a passive film on the coated samples in a PBS solution increased corrosion resistance of Ti-6Al-4V. Tribocorrosion rate of the borided samples decreased up to 40 times compared with Ti-6Al-4V under a reciprocating condition and normal loads of 0.5–15 N against an alumina ball. The presence of B2O3/H3BO3 tribofilm on the borided samples led to a lower coefficient of friction and a more stable fluctuation of OCP.