用于牙科应用的细晶白榴石微晶玻璃的成核与结晶。
The nucleation and crystallization of fine grained leucite glass-ceramics for dental applications.
作者信息
Cattell Michael J, Chadwick Thomas C, Knowles Jonathan C, Clarke Richard L, Samarawickrama Dayananda Y D
机构信息
Centre for Adult Oral Health, Barts and the London, Queen Mary's School of Medicine and Dentistry, University of London, Turner Street, Whitechapel, London E1 2AD, UK.
出版信息
Dent Mater. 2006 Oct;22(10):925-33. doi: 10.1016/j.dental.2005.10.003. Epub 2005 Dec 20.
OBJECTIVES
The aims of the study were to control the nucleation and crystal growth of selected aluminosilicate glass powders, to produce uniform leucite glass-ceramic microstructures consisting of fine (<1000 nm) grained leucite crystals.
METHODS
A starting glass composition of wt%; 64.2% SiO(2), 16.1% Al(2)O(3), 10.9% K(2)O, 4.3% Na(2)O, 1.7% CaO, 0.5% LiO(2) and 0.4% TiO(2) was heated in an electric furnace and later quenched to produce glasses. The glass powders were ball milled to two different particle sizes and heat-treated using one and two-step crystallization heat treatments. Dta, Xrd, and Sem analyses was used to characterise and explore the crystallization kinetics of the glasses.
RESULTS
Selected heat treatments of the glass powders produced a uniform distribution of fine tetragonal leucite crystals (mean+/-S.D.) 0.1+/-0.2 microm(2) in the glassy matrix, with minimal matrix microcraking in the glass-ceramics produced. The addition of a two-step heat treatment increased the leucite volume fraction in all instances.
SIGNIFICANCE
Selected crystallization heat treatments and powder particle sizes were used to control the leucite crystal size, distribution and volume fraction, in order to produce uniformly distributed ultra fine grained tetragonal leucite glass-ceramics for dental applications.
目的
本研究的目的是控制选定的铝硅酸盐玻璃粉末的成核和晶体生长，以制备由细晶粒（<1000 nm）白榴石晶体组成的均匀白榴石微晶玻璃微结构。
方法
将质量分数为64.2% SiO₂、16.1% Al₂O₃、10.9% K₂O、4.3% Na₂O、1.7% CaO、0.5% LiO₂和0.4% TiO₂的起始玻璃组合物在电炉中加热，随后淬火以制备玻璃。将玻璃粉末球磨至两种不同的粒径，并采用一步和两步晶化热处理。使用差示热分析（Dta）、X射线衍射（Xrd）和扫描电子显微镜（Sem）分析来表征和探索玻璃的晶化动力学。
结果
对玻璃粉末进行选定的热处理后，在玻璃基体中产生了均匀分布的细小四方白榴石晶体（平均值±标准差），尺寸为0.1±0.2 微米²，所制备的微晶玻璃中的基体微裂纹最少。在所有情况下，添加两步热处理均增加了白榴石的体积分数。
意义
采用选定的晶化热处理和粉末粒径来控制白榴石晶体的尺寸、分布和体积分数，以便制备用于牙科应用的均匀分布的超细晶粒四方白榴石微晶玻璃。
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