Formation of hydroxyapatite on Ti-coated Ti-Zr-Cu-Pd bulk metallic glass

In this research, Ti coating was conducted on Ti₄₀Zr ₁₀Cu₃₆Pd₁₄ bulk metallic glass (BMG) in order to increase the formation rate of hydroxyapatite layer. The formation behavior of bone-like hydroxyapatite on Ti-coated and uncoated Ti₄₀Zr ₁₀Cu₃₆Pd₁₄ bulk metallic glasses (BMGs) was studied. The surface morphology of Ti-coated and uncoated Ti₄₀Zr ₁₀Cu₃₆Pd₁₄ BMG was investigated by scanning electron microscopy and energy dispersive X-ray spectroscopy. The results revealed that the alkali pretreatment in 5 M NaOH solution at 60°C for 24 h had a beneficial effect on the formation of porous sodium titanate on Ti-coated Ti₄₀Zr₁₀Cu₃₆Pd₁₄ BMG. A bone-like hydroxyapatite layer was able to form on the alkali-treated Ti-coated Ti ₄₀Zr₁₀Cu₃₆Pd₁₄ BMG after a short-time immersion in simulated body fluid (SBF). On the contrary, hydroxyapatite formation was not observed on the uncoated Ti₄₀Zr ₁₀Cu₃₆Pd₁₄ BMG after the same chemical treatments.