| R2O-CaO-MgO-Al2O3-Fe2O3-SiO2 System was chosen as the components of glass-ceramic to study the crystallization influence of Fe2O3 on glass from the ability of crystallization and miscrostructures. On this basis, using the solid wastes—stone powers as the main material to prepare the glass ceramic,the interrelation of difficult or easy to crystallize, miscrostructures, and properties of stone-power glass-ceramic was studied , and application probability of stone-power in glass ceramic was discussed.Glass-ceramic was fabricated by sintering in this study, and one-step and two-step heated treatment were used in crystallization system. DTA,X-ray,SEM,image sintering techniques were introduced to discuss the influence of heated treatment on magnitude of Crystal, grain size. Meanwhile, microstructure and physical-chemical properties of the samples were analyzed to understand the relationship between the composition and properties of stone-powder Glass-ceramic,which provide technical support for more effective use of the powder and theoretical basis.Three series were designed : the influence of Fe2O3 on glass crystallization was studied in the Series 1 and Series 2 in which CaO/MgO ratios were 1 and 1.5, and 1mol %4mol% Fe2O3 were added. The application of stone-powder in glass-ceramics were studied in Series 3. According to the results of the first two series, CaO/MgO ratio was adjusted to 1.3, resulting in the expansion of the scope of the composition of Al2O3 and SiO2A lot of testing and results showed :(1) when a small amount of Fe2O3 (1% mol) was introducted, crystallization parameter of glass-ceramics was possibly increased, and almost all the samples'temperature rang from Tp to Tg overlapped partly ,which means glass samples can be crystallized at the same temperature. When 1mol %3mol% Fe2O3 was introduced into glass, the crystallization parameter was decreased, and the temperature rang from Tp to Tg was narrowed, which indicated the crystallization capability of glass was increased. In addition, there is no distinct impact on the main crystalline phases of glass-ceramics, no matter whether the content contains Fe or not.(2) when the glass-ceramic was preparated with powders, the time of crystallization can be dramatically shorted. When the content of Fe2O3 was controlled within 3%, the beginning and the largest shrinkage temperature can be reduced, and the crystallization rate of crystal can be increased, and precipitation particle size can be reduced. In the condition of full nuclear ,crystal particle size was increased and microstructure was loosened due to the extension of crystallization time, but the change was not significant.(3) stone-powder was used as the main materials to prepare glass-ceramics, and the basic composition of glass-ceramic was :(SiO2) 47-58% (Al2O3) 5-13%.(CaO) 14- 18% (MgO) range of 7-10%, (Fe2O3) 2 -5%.(Na2O) 3-4% (K2O) 4-6%. Main phase is diopside. The utilization rate of the stone-powder (wt%) is up to 20.4-58.35%. The results of glass-ceramic powder sample test showed that :the majority of stone-powder glass-ceramic have a better properties than natural granite,and its properties are nearly or more than those of building glass-ceramic composite plate.In addition, the factor that influence to color of glass ceramic and the reason of production of bubble and crackle have also been discussed and analyzed in this text. The results showed that Al2O3,SiO2 and heated treatment were the main reasons that produced bubble and crackle, color of glass-ceramic was influenced by the crystallization rate of crystal, if crystallization rate of crystal was increased ,the color is low, then the color is dark.
|
PDF Full Text Request