Mechanical, corrosion, and tribocorrosion behavior of biomedical ZrO2 ceramic coatings prepared by thermal oxidation.

For the simultaneous improvement of mechanical, corrosion, and tribo-corrosion properties of Zr–2.5Nb alloy, an adherent black coating was deposited on the Zr–2.5Nb substrate by thermal oxidation in air at different temperatures and times to use in biomedical applications such as knee joints and orthopedic/dental replacements. According to obtained results, the long-term corrosion and tribo-corrosion resistance, and frictional properties in the phosphate-buffered saline solution improved significantly by oxidization at 523 °C for 4 h compared to the bare substrate. XRD patterns and Raman spectra revealed the formation of monoclinic and tetragonal ZrO₂, as well as Nb₂O₅ phases in the black coating. According to microstructural studies, high adherence between the compact oxide layer and substrate decreased due to the formation of micro-cracks in the coating at a high operating temperature of 700 °C. [ABSTRACT FROM AUTHOR]