Novel Ceramic Coating on Titanium with High Mechanical Properties

Phosphate coating layer was produced on titanium substrates by hydrothermal treatment with zinc phosphate solutions. Phosphatizing reaction produced zinc-titanium-phosphate coating layer on the surface by hydrothermal treatment at 250 °C. Ti substrate treated with low concentration of zinc phosphate solution for 14 h was not fully covered by the coating layer. On the other hand, surface coverage on Ti substrate treated with a high concentration of zinc phosphate solution for only 6 h was enhanced completely. SEM and XPS results indicated that the formation of the coating layer was inhibited by surface oxide layer. The coating layer was strongly attached on Ti substrate, moreover, the bonding strength between the coating layer and the Ti substrate was higher than the mechanical strength of binder.