【摘要】 为了探讨热处理制度对SiO2-CaO-Al2O3-MgO-ZnO-Fe2O3系玻璃陶瓷析晶的影响,利用高温熔融法制备基础玻璃,并用扫描电子显微镜(SEM)和X射线衍射(XRD)等技术考察玻璃陶瓷的析晶特征。结果表明:在所研究的玻璃体系中析出主晶相为锌橄榄石(Ca2ZnSi2O7),部分氧化锌和氧化铁固溶到硅灰石(CaSiO3)中,形成辉石类晶体(Ca(Fe,Zn)Si2O6)。热处理制度对析出晶体的种类影响不大,但是对析出晶体的形态有较大程度的影响。在随炉升温的情况下,试样表面形成枝状Ca(Fe,Zn)Si2O6晶体,而在内部形成Ca2ZnSi2O7和Ca(Fe,Zn)Si2O6。两种晶体相互交替析出,形成条带状组织。在750℃的保温有利于晶体的整体析出。更多还原

【Abstract】 To explore the influences of the thermal treatment on the crystallization and the microstructural morphology in SiO2-CaO-Al2O3-MgO-ZnO-Fe2O3 glass system, the base glass was prepared by melt quenching methods and the crystallizing behavior were investigated by using XRD and SEM techniques. The results show that the main crystalline phase precipitated in the present system is calcium zinc silicate (Ca2ZnSi2O7), and the second phase is calcium iron zinc silicate (Ca(Fe,Zn)Si2O6), not commonly observed as wollastonite(CaSiO3) , suggesting the ion of Zn2+ and Fe3+ be substituted for Ca2+ ion. The varieties of crystalline phases, which always are Ca2ZnSi2O7 and Ca(Fe, Zn)Si2O6 in the samples with the various thermal treatments, are less influenced. However, the morphologies are more influenced by the processes of heat treatment. In the nearly free surface, the crystals, (Ca(Fe, Zn)Si2O6), exhibit dendritic growth. However, in the bulk region, Ca2ZnSi2O7 and (Ca(Fe, Zn)Si2O6 which are precipitated alternately with each other, reveal the eutectic-formed morphology. The annealing at 750℃ is favored to the bulk crystallization.更多还原