Obtaining, characterisation and protective properties of hydroxyapatite coating on new Ti-Ta-Zr alloy surface

摘要

The hydroxyapatite (HA) coating was obtained by chemical deposition from a green solution, slightly supersaturated in calcium and phosphorous ions. After 7 hours of soaking in solution, the existence of HA was proved by scanning electron (SEM) micrographs and energy dispersive X-ray (EDX) spectrum: the coating has nanometric morphology with pores and crystals and contains calcium, phosphorous and oxygen elements. The coating elemental analysis and the identification of its composition was carried out with X-ray photoelectron spectroscopy (XPS); the high resolution XPS spectrum for each element revealed that both calcium, Ca 2p and phosphorous, P 2p presented the energetic peaks specifically for HA. The concentrations of these elements showed that the Ca/P ratio is about 1.9 like in biological HA and the coating thickness is 6 nm.