Nucleation mechanisms in a SiO2-Li2O-P2O5-ZrO2 biomedical glass-ceramic: Insights on crystallisation, residual glasses and Zr4+ structural environment

Author(s):  
M.R. Cicconi ◽  
R. Belli ◽  
M. Brehl ◽  
J. Lubauer ◽  
T. Hayakawa ◽  
...  
Author(s):  
P.P.K. Smith

Grains of pigeonite, a calcium-poor silicate mineral of the pyroxene group, from the Whin Sill dolerite have been ion-thinned and examined by TEM. The pigeonite is strongly zoned chemically from the composition Wo8En64FS28 in the core to Wo13En34FS53 at the rim. Two phase transformations have occurred during the cooling of this pigeonite:- exsolution of augite, a more calcic pyroxene, and inversion of the pigeonite from the high- temperature C face-centred form to the low-temperature primitive form, with the formation of antiphase boundaries (APB's). Different sequences of these exsolution and inversion reactions, together with different nucleation mechanisms of the augite, have created three distinct microstructures depending on the position in the grain.In the core of the grains small platelets of augite about 0.02μm thick have farmed parallel to the (001) plane (Fig. 1). These are thought to have exsolved by homogeneous nucleation. Subsequently the inversion of the pigeonite has led to the creation of APB's.


Author(s):  
T.R. Dinger ◽  
G. Thomas

The use of Si3N4, alloys for high temperature, high stress structural applications has prompted numerous studies of the oxynitride glasses which exist as intergranular phases in their microstructures. Oxynitride glasses have been investigated recently in their bulk form in order to understand their crystallization behavior for subsequent Si3N4 applications and to investigate their worth as glass-ceramic precursors. This research investigates the crystallization sequence of a glass having a normalized composition of Y26Si30Al11 ON11 and lying in the A1N-Y2O3-SiO2 section of the Y-Si-Al-O-N system. Such glasses exist as intergranular phases in the technologically important Y2O3/Al2O3-fluxed Si3N4 alloys.


1986 ◽  
Vol 47 (C8) ◽  
pp. C8-901-C8-904 ◽  
Author(s):  
G. N. GREAVES ◽  
P. J. HALFPENNY ◽  
G. M. LAMBLE ◽  
K. J. ROBERTS

2008 ◽  
Author(s):  
Xiaomei Guo ◽  
Kewen Kevin. Li ◽  
Xuesheng Chen ◽  
Yingyin Kevin. Zou ◽  
Hua Jiang

2013 ◽  
Vol 12 (2) ◽  
pp. 337-342 ◽  
Author(s):  
Firuta Goga ◽  
Roxana Dudric ◽  
Calin Cormos ◽  
Florica Imre ◽  
Liliana Bizo ◽  
...  

2004 ◽  
Vol 46 (5) ◽  
pp. 243-247
Author(s):  
Wolfram Harbich ◽  
Udo Mücke ◽  
Georg Berger

2004 ◽  
Vol 95 (2) ◽  
pp. 97-101 ◽  
Author(s):  
Hongyuan Sun ◽  
Qiye Wen ◽  
Peixin Zhang ◽  
Jianhong Liu ◽  
Qianling Zhang ◽  
...  

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