Research On Composite Biological Glass Ceramics

To select Na2O-B2O3-SiO2as the basic glass system, Na2O-B2O3-SiO2-CaO-P2O5and Na2O-B2O3-SiO2-CaO-P2O5-F glass ceramics mixed with different percentage ofCaO, P2O5, F were prepared by sintering. The effects of different amount of CaO, P2O5, F,and temperature on crystallization and sintering of the system were studied by XRD,SEM and other analytical methods.The results showed that the main crystalline phase of Na2O-B2O3-SiO2-CaO-P2O5glass ceramics was hydroxyapatite. And an increase in temperature of heat treatment andCaO, P2O5content was conducive to the precipitation of main crystalline phase andsintering. After comprehensive analysis, samples10-3adding40%CaO and16%P2O5hadexcellent crystallization and sintering properties after heat treatment at750℃. The maincrystalline of Na2O-B2O3-SiO2-CaO-P2O5-F（P2O5/F=11.2）glass ceramics was fluoro-hydroxyapatite. CaO、P2O5、F could promote the precipitation of cristobalite and themore adding amount was more beneficial to the precipitation of main crystallizationphase. The precipitation amount increased with the rising heat treatment temperature. Thecrystal morphology growth was from needle-like grains of1~3μm to six squarecolumnar crystals of5~10μm. The sintered specimens became dense firstly and thenwere overheated with the increasing temperature. The samples1-2adding12%P2O5,30%CaO and1.07%F had good crystallization and sintering densification after heattreatment at810℃. The volume density was2.6169g/cm-3, the bibulous rate was only0.17%and the microhardness was1337.74MPa. The main crystal phase of Na2O-B2O3-SiO2-CaO-P2O5-F (P2O5/F=7.46) glass ceramics of excessive fluoride was fluoro-hydroxyapatite, which had excellent crystallization and sintering properties withincreased adding amount of P2O5、CaO、F in the low heat treatment temperature rangeof690℃~720℃. The grain size was2~10μm, the microhardness was excellent. As theheat treatment temperature continued to rise, the main crystalline phase woulddecompose and the samples would be overburning. The samples introduced by12%P2O5,40%CaO and2.2%F had good sintering and crystallization properties after heat treatmentat720℃. The volume density was2.7303g/cm-3, the porosity was0.5611%, the waterabsorption was0.2055%and the microhardness was1203.15MPa. The addition offluoride effectively promoted to sintering and decreased the crystallization temperature.But excessive amount of fluoride addition at high heat treatment temperature made themain crystalline phase decompose.By the Na2O-B2O3-SiO2-CaO-P2O5and the Na2O-B2O3-SiO2-CaO-P2O5-F glassceramics research, we get the further understanding that the temperature and the addingamount of CaO, P2O5, F have effect on the crystallization and sintering performance.