MACHINABLE CALCIUM PHOSPHATE CERAMICS
2002 年 13 巻 p. 153-158
詳細
2002 年 13 巻 p. 153-158
SiO2-free calcium phosphate ceramics with easy machinability were prepared by crystallization of the glasses in the CaO-P2O5-TiO2-Na2O system. β-Ca2P2O7- and β-Ca3(PO4)2-containing glass-ceramic, which was prepared by sintering of a compact of 6OCaO-30P2O5-3TiO2-7Na2O (in mol%) glass powders at 850°C, was found to show good machinability, as confirmed by a drilling test using a conventional carbide tool. SEM observation of the glass-ceramic showed that β-Ca2P2O7 crystals having a layered morphology are interlocking one another; plate-like crystals of several tens nanometers in thickness are piled up. The easy machinability of the glass-ceramics was suggested to result from the cleavage of β-Ca2P2O7 crystals precipitated in the glass. By volume-crystallization of a 43CaO-30P2O5-25TiO2-2Na2O glass, the glass-ceramic containing β-Ca2P2O7 and (Cao.5, Na)Ti2(PO4)3 crystals was found to be prepared. The glass-ceramic also could be drilled using a conventional carbide tool. These glass-ceramics in the present work have relatively high strength of ~120 MPa in bending.
