In recent years, the use of bioactive calcium phosphate coatings for biological fixation of load-bearing implants has been attracting much attention. Many techniques have been used to produce calcium phosphate, especially hydroxyapatite (HAP) coatings on metallic substrates. In this paper, a simple wet-chemical method, chemical bath deposition is reported to prepare calcium hydroxyapatite coatings on a Ti plate at relatively low temperature (95°C). The method is based on chelating calcium ions with a complex reagent and then increasing the temperature to dissociate the calcium ions, which induces the precipitation of HAP. EDTA is chosen as the complexion agent. At 60-95°C the Ca(EDTA)2-
complex thermally dissociates and releases free calcium ions. Substrates used in this research are Ti plates with 0.2mm in thickness. The substrates were gritted by metallographic Al2
paper and then treated in a solution of 2mol/dm3
KOH at 95°C for 1 hour. The HAP coatings were performed in a chemical bath that was heated from 60°C to 95°C. XRD data indicated that the coatings are highly crystalline. FTIR and EDX analyses revealed that the coatings consist of Ca-deficient apatite. SEM micrographs of the coatings show that the coating is composed of evenly small crystal grains. The surface was uniform without apparent pores or agglomerates.