Thin Carbonate-containing Apatite Coating of a Titanium Web using a Molecular Precursor Method under Oxygen Gas Introduction

SYNOPSIS Thin carbonate-containing apatite (CA) coatings were deposited onto titanium webs (TW) using a molecular precursor method. The volumetric porosity and fiber diameter of the TW were 87 % and 50 μm, respectively. A molecular precursor solution was obtained by adding dibutylammonium diphosphate salt to Ca-EDTA/ amine ethanol solution by adjusting the Ca/P ratio to 1.67. Two molecular precursor solutions with different calcium ion concentrations, 0.157 mmol/g (0.157-precursor) and 0.470 mmol/g (0.470-precursor), were prepared. Each sintered TW was immersed in the molecular precursor solution and then heated at 600 oC for 2 hr under oxygen gas introduction. Without oxygen gas, the CA coated TW appeared darker and blacker. Oxygen gas introduction produced a whiter TW appearance after CA coating. Three-times coating of 0.157-precursor produced a CA coating that covered the surface of the TW as well as its center. By using the 0.470-presursor, a single application of CA covered the inside as well as the surface of the TW. Increasing the calcium ion concentration of the molecular precursor solution enabled one-time application for effective CA coating not only of the surface of the TW but also its center. In conclusion, one-time application of 0.470-precursor solution during oxygen gas introduction produces a sufficiently CA coated TW.