Papers by Author: Hao Liu

Abstract: Calcium-magnesium-silicate glass fiber is a kind of candidate materials for aluminosilicate ceramic fiber in high temperature resistant field. However, the large thermal shrinkage limits its rapid development and industrial application in high temperature insulation field. It has been known that the shrinkage under high temperatures is mainly affected by the structure and crystallization mechanisms of glass fibers. Thus, Al2O3 was chosen as additive in the chemical composition of glass fiber to investigate the glassy network structure, crystallization and dissolution properties of calcium-magnesium-silicate glass fiber by DTA, XRD and ICP-AES techniques. The results show that with the addition of Al2O3, the glassy network structure was strengthened and the precipitation of crystals was inhibited for heat-treated fibers. As for the dissolution properties in physiological fluids, though the weight losses, changes of pH values and leached ions concentration lowered slightly with the addition of Al2O3 for the intensified network structure, fibers still present high dissolution rates.

Abstract: Structure, viscosity and crystallization behavior of CaO-MgO-SiO₂ ceramic fiber with Nd₂O₃ were investigated by DTA, XRD and FTIR techniques. The results show that the addition of Nd₂O₃ enhanced the fiberization by extending the viscosity curve of the glass melt to lower temperature and improved the melt fiberizability. With the reinforcement of silicate glass network by Nd³⁺, the precipitation of crystals in fibers was inhibited at high temperatures.

Abstract: CdS doped lead silicate glasses were prepared with the conventional fusion method. The effects of the ZnO/CdS ratio and the content of CdS on the preparation of CdS doped glasses were both studied. The crystallization process of CdS nanocrystals was investigated by X-ray diffractometry and scanning electron microscopy. Utilizing the Maker fringe method, Second harmonic generation (SHG) was observed from CdS doped glasses without any poling procedures. The SH intensity gets enhanced by increasing the heat-treatment temperature and prolonging the heat-treatment duration.

Abstract: The effects of replacement of MgO by CaO, on the characterization and crystallization behavior of glas-ceramics in the CaO-MgO-SiO2 system were investigated by DTA, XRD and FTIR techniques and by density measurements. The results show that the glass transition temperature (Tg) and crystallization temperature (Tc) increase and glassy structural network becomes denser with increasing the CaO/MgO weight ratio. After certain heat-treatment procedure, the major crystal phases change from calcium magnesium silicate (diopside) to calcium silicate (parawollastonite) at the replace of MgO by CaO. Studying of density measurement shows that, the density of glass samples increase by increasing CaO content on the expense of MgO.