Preparation of Calcium Phosphate Glass-Ceramics and Their Coating on Titanium Alloys

摘要

Novel silica-free calcium phosphate glass-ceramics was prepared by heating a compact of 60CaO centre dot 30P_2O_5 centre dot 3TiO_2 centre dot 7Na_2O glass powders. When powder-compacts of the glasses were heated at 850 deg C, they crystallized and subsequently sintered, resulting in glass-ceramics containing #beta#-Ca_3(PO_4)_2 and #beta#-Ca_2P_2O_7 crystalline phases. The glass-ceramics show relatively high mechanical strength of 100 approx 120 MPa in bending and fracture toughness of K_(IC) approx = 1.9 MPa centre dot m~(0.5). Hydroxyapatite was formed newly on the surface of the glass-ceramic in simulated body fluid at 37 deg C. By heating a new type of titanium alloy (Ti-29Nb-13Ta-4.6Zr), on which the glass powders were placed, at 800 deg C in air, a glass-ceramic layer containing #beta#-Ca_3(PO_4)_2 crystal was found to be joined easily with the metal. The joining between the coating layer and the metal substrate is very strong in tensile bonding strength.