Ym. Sung et S. Kim, Sintering and crystallization of off-stoichiometric SrO center dot Al2O3 center dot 2SiO(2) glasses, J MATER SCI, 35(17), 2000, pp. 4293-4299
Grass-ceramics with the celsian-corundum binary join composition of 88.8 wt
% SrO . Al2O3. 2SiO(2) -11.2 wt% Al2O3, (SA2S-A), were fabricated by pressu
reless sintering and investigated for their sintering and crystallization b
ehaviors. The (SA2S-A) glass powder showed crystallization peak and melting
temperatures of similar to 1059 and 1550 degrees C, respectively and high
sintering ability. The (SA2S-A) glass powders containing B2O3, (SA2S-A)B an
d those containing B2O3 and TiO2, (SA2S-A)BT showed lowered crystallization
peak temperatures of 1033 and 997 degrees C, respectively. By applying Kis
siger analyses to the DTA data of the (SA2S-A), (SA2S-A)B and (SA2S-A)BT gl
ass powders, the activation energy values for crystallization were determin
ed as 488, 370 and 333 kJ/mol, respectively. The Ozawa analyses on the DTA
data gave the Avrami parameter values at 1.2, 1.1 and 1.9, respectively for
the (SA2S-A), (SA2S-A)B and (SA2S-A)BT glass powders. The x-ray diffractio
n (XRD) patterns of the (SA2S-A) glass-ceramics, crystallized at 1100 degre
es C for 4 h, showed formation of both the monocelsian and hexacelsian phas
es. The (SA2S-A)B and (SA2S-A)BT glass-ceramics crystallized at 1100 degree
s C for 1 h, showed formation of the phase-pure monocelsian and did not sho
w any evidence of the hexacelsian formation prior to the monocelsian format
ion. (C) 2000 Kluwer Academic Publishers.