| 摘要 |
PURPOSE:To develop a calcium phosphate crystallized glass body which has excellent flexural strength and permits easy casting by forming said glass body into the structure in which the dendrites of the apatite crystal grains grown to prescribed sizes are entangled with each other via a glass phase and the structure in which wollastonite crystal grains exist mixedly with the apatite crystal grains in the glass phase. CONSTITUTION:Glass cullet is formed by mixing MgO, CaCO3, Ca2P2O7, SiO2, CaF and CeO at prescribed ratios, melting the mixture at 1,500 deg.C and cooling the melt. The glass cullet is remelted at 1,400-1,530 deg.C and is quickly cooled at 300-700 deg.C/sec cooling rate to suppress the crystallization of the apatite prior to a heat treatment for the purpose of crystallization. Said cullet is subjected to a preliminary heat treatment at 400-800 deg.C to remove the strain generated during the quick cooling prior to the crystallization. The dendrites B of the fine apatite A are simultaneously grown to 0.1-10mum size to form the structure in which the wollastonite crystal grains C exist mixedly in the glass phase D. The calcium phosphate crystallized glass body having >=15kg/mm<2> flexural strength at least at 3 points bending is developed. |
