RAPID COATING OF Ti6Al4V AT ROOM TEMPERATURE WITH A CALCIUM PHOSPHATE SOLUTION SIMILAR TO 10x SIMULATED BODY FLUID

High ionic strength ( > 1100 mM) calcium phosphate solutions were used in depositing 20-65-micron-thick, bonelike apatitic calcium phosphate on Ti6Al4V within 2-6 h, at room temperature. The super-strength solution used multiplied the concentrations of calcium and phosphate ions in human plasma or simulated body fluid (SBF) by a factor of ten. The solutions did not contain buffering agents and the formation of calcium phosphate nano-clusters did not adversely affect the coating process. After the preparation of the solution, the only step needed was the addition of proper amounts of NaHCO3 to raise the pH to 6.5 prior to the coating procedure. The adhesion strength (12 plus or minus 2 MPa) of the coatings was comparable to coatings produced by soaking in 1.5x SBF solutions over a prolonged period of time. The carbonate content (8 wt%) and Ca/P molar ratio (1.57) qualified the coating as bonelike. 36 refs.