Structure-property relationships and densification-crystallization behaviours of simplified lithium disilicate glass compositions
authors Fernandes, HR; Tulyaganov, DU; Pascual, MJ; Ferreira, JMF
nationality International
journal CERAMICS INTERNATIONAL
author keywords Microstructure-final; Thermal properties; Glass; Glass-ceramics
keywords MAS-NMR; LI2O-SIO2 GLASS; FORMING ABILITY; CERAMICS; K2O; MICROSTRUCTURE; STRENGTH; SYSTEM; AL2O3; MELTS
abstract The role of each oxide component on the structure of molten glass and on their densification and crystallization behaviours is expected to be more easily assessed for compositions comprising a small number of components. In the present work, binary (Li2O-SiO2), ternary (Li2O-Al2O3-SiO2), and quaternary (Li2O-K2O-Al2O3-SiO2) glass compositions were selected. The aim was to investigate the relationships between the compositions and structure of the glasses, namely, the effects of each component on the extent of liquid-in-liquid phase separation, their thermal behaviour and the phase assemblage in the disilicate glass-ceramics. The distribution of structural units in the experimental glasses was assessed using Si-29 MAS-NMR spectroscopy. Adding Al2O3 played a dual role as network former and modifier when added to the binary system by enhancing Q(2) and diminishing Q(3) structural units. The processing window for sintering, the difference between the onset of crystallisation and glass-transition temperature (T-c-T-g), was too narrow for the less polymerised network structures (binary and ternary systems), hindering the densification of the corresponding glass powder compacts. Oppositly, compositions in the quaternary system featured excellent densification behaviour coupled with high mechanical strength. These features derive from a more rigid glass network comprising four coordinated (AlO4/2)(-) units and K+ cations in its vicinity. (C) 2013 Elsevier Ltd and Techna Group S.r.l. All rights reserved.
publisher ELSEVIER SCI LTD
issn 0272-8842
year published 2014
volume 40
issue 1
beginning page 129
ending page 140
digital object identifier (doi) 10.1016/j.ceramint.2013.05.113
web of science category Materials Science, Ceramics
subject category Materials Science
unique article identifier WOS:000330820500018
  ciceco authors
  impact metrics
journal analysis (jcr 2017):
journal impact factor 3.057
5 year journal impact factor 2.882
category normalized journal impact factor percentile 94.444
dimensions (citation analysis):
altmetrics (social interaction):



 


Apoio

1suponsers_list_ciceco.jpg