CALCIUM PHOSPHATE FORMATION ON Ti ALLOY BY PRECALCIFICATION PROCESS AT STATIC CONDITIONS

The influence of precalcification on the nucleation and growth of calcium-phosphates crystals (Ca-P) on the surface of Ti alloy was studied. Ti alloy was precalcified by the calcification solutions (SCS1-3) with different contents of Ca2+ and (PO4)3- ions and compared with the non-precalcified sample. The results of Ca2+ and (PO4)3- analysis indicate that the precalcification step accelerates the consumption of both Ca2+ and (PO4)3- ions from simulated body fluid (SBF) solution. The deposition of Ca-P phase was completed approximately 6 days earlier when compared with the non-treated samples. Analytical measurements as well as surface observation enable the optimal calcification solution marked as SCS2 containing (mmol/dm3) 4.0 Na+, 5.0 Ca2+, 10.0 Cl-, 2.5 H2PO4- and 1.5 HCO3- to be found. The influence of S/V ratio (surface area/volume of soaking media) changes on the nucleation and thickness of Ca-P layer formed in the SCS2 solution was studied. 4 days' immersion in SCS2 solution at S/V ratios at 0.1 and 0.5 cm-1, respectively, is enough time for complete deposition by Ca-P phase on the alloy surface. The changes in the S/V ratio allow for adjustment of the thickness of the Ca-P layer on the surface. 8 refs.