Impact of reactive nitrogen flow on morphology, mechanical properties, and biocorrosion behavior of sputtered TiN coatings towards orthopedic applications

This work aimed to investigate the effects of reactive nitrogen flow on the morphology, mechanical properties, and biocorrosion behavior of TiN coatings deposited on Ti6Al4V alloys and Si (100) wafer by direct current (DC) magnetron sputtering technique. From analysis results of x-ray diffraction (XRD) and scanning electron microscope (SEM), it revealed that the preferred orientation of the coatings changed from TiN (111) to TiN (200) plane, and the surface morphology altered from faceted structures to closed sphere structures with the increasing reactive N-2 flow. The high density and fine grain size of the coating deposited with a reactive N-2 flow of 25 sccm resulted in the highest hardness (24.8 & PLUSMN; 1.8 GPa) and the best corrosion resistance. In addition, the friction coefficient was reduced owing to the decrease in the grain size as reactive N-2 flow increased from 10 to 30 sccm. Compared with Ti6Al4V substrate, TiN coatings possess better corrosion resistance, suggesting that the coating is beneficial for improving the performance of the Ti6Al4V alloys.