Phase Evolution and Microstructure Characteristics of Calcium Phosphate Based Glass Ceramics Prepared by Sol-Gel Technique
Calcium phosphate based glasses and glass-ceramics in the system of 54CaO-36P2O5- (10-x)Na2O-xSrO were fabricated by sol-gel method. The structures of the glasses were investigated by Fourier transform infrared spectroscopy and X-ray diffraction has been used to determine the crystallize phase from glass matrix. The synthesized glass matrix shows a metaphosphate-like structure which consists of a chain and /or ring structure. After sintered at 1150 °C, the crystalline phase -Ca2P2O7 and a small quantity of amorphous glass were observed clearly. With 1.0 mol% addition of SrO, the average grain size of -Ca2P2O7 was obviously decreased and some of them were covered with amorphous glass. When the content of strontium reached to 5.0 mol%, only a little crystalline phase -Ca2P2O7 can be found in the glass matrix, while the grain size has no significant change, compared with that of the sample containing 1.0 mol% SrO. The results showed that SrO addition to 54CaO-36P2O5-10Na2O system can inhibit the crystallization of -Ca2P2O7 and decrease the grain size, and then adjust the degradation rate in body fluid by controlling the ratio of -Ca2P2O7 to amorphous glass.
Wei Pan and Jianghong Gong
X. D. Li et al., "Phase Evolution and Microstructure Characteristics of Calcium Phosphate Based Glass Ceramics Prepared by Sol-Gel Technique", Key Engineering Materials, Vols. 434-435, pp. 572-575, 2010