An in situ high-temperature X-ray diffraction study of early-stage crystallization in lithium alumosilicate glass-ceramics

作者：Dressler Martina; Rü dinger Bernd; Deubener Joachim^*

来源：Journal of the American Ceramic Society, 2011, 94(5): 1421-1426.

DOI：10.1111/j.1551-2916.2010.04252.x

• Alumosilicates
• Avrami analysis
• Crystal size
• Crystallization process
• High temperature X-ray diffraction
• In-situ
• Kinetic exponent
• Lattice parameters
• Number density
• Quartz solid solution
• Si/Al ratio
• Temporal development
• Two stage
• Unit cell parameters

In situ high-temperature X-ray diffraction data have been collected for the crystallization of high-quartz solid solution (hq-ss) in a Li 2O-Al2O3-SiO2 glass-ceramic. The temporal development of the number density, size, and unit cell parameters of hq-ss crystals indicated a two-stage crystallization process. At the early stage, lattice parameters of hq-ss crystals were constant. Their number density increased at a maximum rate of 1.7×1012&middot(mm 3&middotmin)-1 up to 1.4×1014 mm -3, while hq-ss grew linear with time at a maximum rate of &asyum;1 nm/min up to a size of &asyum;21 nm. In contrast, a decrease of the a-unit cell parameter, characteristic for increasing Si/Al ratios of the hq-ss crystals, was evident at the later stage. At this stage, the average crystal size was >21 nm. Their number density was constant or decreased linearly with time. The growth kinetics were very shallow with the exponent &asyum;1/50, but reached for crystals >30 nm cube root dependence typical for diffusion-controlled ripening. Avrami analysis of the volume fraction Vf confirmed these findings and resulted in a kinetic exponent in the range from 3.5 to 4.8 for the first (Vf<45%) and <0.3 for the second stage. ? 2010 The American Ceramic Society.

• 出版日期2011