MgO-ZnO-Al2O3-SiO2玻璃陶瓷之相變化與性質研究

Phase Transformation and Properties of MgO-ZnO-Al2O3-SiO2 Glass-Ceramics

蔡維哲(Wei-Che Tsai)

指導教授 ： 徐錦志

大同大學/工程學院/材料工程學系所/碩士(2005年)

摘要

具有高彈性模數、優異強度、表面平坦性及韌性之微晶玻璃陶瓷已被發展用來當作電腦硬碟基材之材料。本研究是以MgO - ZnO - Al2O3 - SiO2為主要的成分，再添加不同TiO2含量作為成核劑，用高溫熔淬的方式製備出玻璃塊材，再施以成核及成長熱處理，希望得到其主結晶相為spinel + enstatite之玻璃陶瓷。
實驗結果顯示，當TiO2含量增加，玻璃產生相分離之能力上升，但當TiO2含量≧13.5wt﹪，會降低起始玻璃的形成能力，造成結晶。故本研究中設計一種三階段式熱處理，可將有效獲得主結晶相為spinel + enstatite之TiO2含量降低，並且抑制high-quartz s.s.析出。
在機械性質方面，隨著熱處理溫度升高，其硬度與楊氏係數皆明顯上升，楊氏係數最高可達155 GPa。

關鍵字

表面粗度 ； 楊氏係數 ； 玻璃陶瓷 ； 磁碟機板 ； 三階段式熱處理 ； 維克式硬度

並列摘要

Nanocrystalline glass-ceramics with high elastic modulus, moderate strength, extremely smooth polished surface, and toughness have been developed recently for potential use as magnetic disk substrate in computer hard drives. The major objective of this study is to explore the effect of TiO2 on the crystallization and properties of MgO - ZnO - Al2O3 - SiO2 glass-ceramics. The parent glasses was formed by a melt-quench process, then subjected to nucleation and crystallization heat-treatment to convert it into glass-ceramics containing spinel and enstatite as the major crystalline phases.
The experimental results indicate that while increases in the TiO2 amount enhanced the phase separation of glass, the glass formation ability was reduced. In this study, a three-stage crystallization heat treatment was proposed to decrease the TiO2 amount that is required for fabricating spinel + enstatite glass-ceramics, and inhibiting the precipitation of high-quartz s.s..
The Vickers hardness and Young’s modulus of the glass-ceramics increased obviously with the increase in the heat-treatment temperature. The highest Young’s modulus that can be reached is 155 GPa.

並列關鍵字

glass-ceramics ； magnetic disk substrate ； spinel-enstatite ； surface roughness ； three-stage heat treatment ； vickers hardness ； young's modulus

參考文獻

[1] R.A. Miller, “Substrates for Magnetic Hard Disks for Gigabit Recording” IEEE Trans. Mag., 32, 1805-1811 (1996).

[5] L.R. Pinckney and G.H. Beall, “Nanocrystalline non-alkali glass-ceramics,” J. Non-Cryst. Solids, 219, 219-227 (1997).

[6] G. H. Beall, “Chain Silicate Glass-Ceramics,” J. Non-Cryst. Solids, 129, 163-173 (1997).

[12] P. Wang, T. Hőche, C. Rűssel and J. D. Schnapp, “Microstructure - property relationship in high - strength MgO-Al2O3-SiO2-TiO2 glass-ceramics,” J. Non-Cryst. Solids, 298, 137-145 (2002).

[13] J. H. Simmons et al., “Nucleation and Crystallization in Glass” The Am. Cera. Soc., Inc. Columbus, Ohio, 1-48 (1982).