- 學位論文
添加氧化鈦於鋰鋁矽酸鹽玻璃陶瓷在失透過程中顯微結構的變化
Effect of adding TiO2 on the microstructure of lithium aluminosilicate glass ceramics during devitrification processes
摘要
本論文主要探討鋰鋁矽酸鹽玻璃陶瓷，在氧化鈦成分比例(共有 0 wt%、1 wt%、2 wt%、4 wt%共四種比例)的試樣，經過不同的熱處理條件下，使用X光粉末繞射、X光吸收光譜術和紅外光吸收光譜術分析其內部微結構與相改變之間的關係。由X光粉末繞射我們發現主晶相(β-石英固溶體、β-鋰輝石固溶體)的相轉變熱處理溫度會隨氧化鈦添加量的增加而降低，而且熱處理溫度的上升有助於次要相(金紅石、鈦酸鋯、矽酸鋯、鋅或鎂尖晶石)晶體的成長。從X光近吸收邊緣的光譜特徵可知鈦、鋯元素週遭原子結構隨熱處理條件的變化。當試樣從非晶質玻璃相轉變為高度結晶相時，這兩種元素的配位數會從低的配位數轉變為高的配位數（鈦從4配位變為6配位，鋯從6變成8配位）。不過添加氧化鈦4 wt%的試樣就沒有配位數變化的趨勢，但由鈦K層的X光近吸收邊緣光譜相當類似六配位鈦的金紅石結構；而鋯K層的X光近吸收邊緣光譜類則近似於八配位鋯的矽酸鋯結構。紅外光吸收光譜術不能夠直接推測主晶相或是次要相的種類，不過可以間接由吸收波段的變化，判斷參與相變化的元素週邊原子的鍵結與鍵結的振動形式，進一步證實X光粉末繞射中主晶相的變化。
並列摘要
In the thesis, we changed the titanium dioxide contents under different heat treatment conditions to observe the variations of the inner microstructure while the phase transform. X-ray powder diffraction, X-ray absorption spectroscopy and infrared spectroscopy were used. According to the XRD results, while the titanium dioxide contents were increased, the phase transformation temperatures of the main phases (β-quartz solid solutions and β-spodumene solid solutions) were decreased. And then various secondary phases were usually precipitated at higher temperatures. XAS showed that the local environment of Ti and Zr were changed by different thermal treatment conditions. According to the XANES of Ti (Zr) K-edge studies, the coordination numbers changed from lower to higher coordination number while the sample transforms from an amorphous glass to a highly crystalline glass ceramics (Ti from 4 to 6, Zr from 6 to 8). But these phenomena would not be observed at the samples of the 4 wt% TiO2. More information about the materials fine structure can be obtained from infrared spectroscopy data. We could utilize the variations of the IR spectral feature to decide that the bond of the inner atoms, the kinds of bonding vibration and the phase type.