Surface phenomena of HA/TiN coatings on the nanotubular-structured beta Ti-29Nb-5Zr alloy for biomaterials

► Surface phenomena of HA/TiN coatings on the nanotubular structured beta Ti-29Nb-5Zr alloy for biomaterials have been investigated by several experimental methods. ► The nanotubular structure was formed by anodizing. ► Hydroxyapatite (HA)/titanium nitride (TiN) films were deposited on Ti-29Nb-5Zr alloy specimens using a magnetron sputtering system. ► The Ti-29Nb-5Zr alloy substrate had small grain size and preferred orientation along the drawing direction. ► The HA/TiN coating was stable with a uniform morphology at the tips of the nanotubes.