BONE-LIKE APATITE COATING OF ALUMINA AND ZIRCONIA BY RF-MAGNETRON SPUTTERING

We have developed the coating technology of apatite onto strong materials such as the ceramics of alumina and zirconia, and the metals of titanium and stainless steel, and recently established the method for the formation of bone-like layers of partially carbonated calcium hydroxyapatite by a reactive rf-magnetron sputtering method, which is undertaken in a mixed CO2/Ar gas ambience. Essential to this method is the use of calcium phosphate glass targets with much lower Ca/P ratios than the stoichiometric value of hydroxyapatite. It has been identified by the surface analyses of XRD, EDX, and FT-IR that CO32- ions occupied the lattice positions of PO43- in the apatite structure. The bioactivity of the coated ceramic materials was confirmed by the in vitro experiments of the bone-like crystal growth on their surfaces in a simulated body fluid.