TY  - JOUR
AU  - El-Buaishi, Nozhat Moftah
AU  - Veljović, Đorđe
AU  - Jokić, Bojan
AU  - Radovanović, Željko
AU  - Steins, Ints
AU  - Janaćković, Đorđe
AU  - Petrović, Rada
PY  - 2013
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2531
AB  - Cordierite powders synthesized by colloidal and alkoxide sol-gel methods were conventionally and spark-plasma sintered. The powders for the sintering investigations were obtained by calcination of the gels at a temperature where alpha-cordierite is formed (crystalline powders) or at a temperature where densification without crystallization of silica-containing component occurred (amorphous powders). All the calcinated gels were ground for 3 h, uniaxial pressed at 400 MPa and sintered conventionally at 1400, 1430 and 1450 degrees C for 2 h. In order to improve the sintering behavior of the cordierite powders, spark-plasma sintering (SPS) was applied. The microstructures and the phase composition of the obtained cordierite materials were analyzed using scanning electron microscopy (SEM) and X-ray diffraction analysis and the mechanical properties of the materials were determined. It was shown that the sinterability of the colloidal powders was much better than that of the alkoxide powders. Conventional sintering at 1400 degrees C of the crystalline powder produced by the colloidal method gave the material of the best mechanical properties. The sinterability of the crystalline alkoxide cordierite powder was highly improved by spark-plasma sintering at a lower sintering temperature (1350 degrees C), for a very short period of tithe (7 min). The density of the obtained material was very close to the theoretical density of alpha-cordierite and the mechanical properties were better than those of materials obtained by conventional sintering.
PB  - Elsevier Sci Ltd, Oxford
T2  - Ceramics International
T1  - Conventional and spark-plasma sintering of cordierite powders synthesized by sol-gel methods
EP  - 5854
IS  - 5
SP  - 5845
VL  - 39
DO  - 10.1016/j.ceramint.2012.12.101
ER  - 

@article{
author = "El-Buaishi, Nozhat Moftah and Veljović, Đorđe and Jokić, Bojan and Radovanović, Željko and Steins, Ints and Janaćković, Đorđe and Petrović, Rada",
year = "2013",
abstract = "Cordierite powders synthesized by colloidal and alkoxide sol-gel methods were conventionally and spark-plasma sintered. The powders for the sintering investigations were obtained by calcination of the gels at a temperature where alpha-cordierite is formed (crystalline powders) or at a temperature where densification without crystallization of silica-containing component occurred (amorphous powders). All the calcinated gels were ground for 3 h, uniaxial pressed at 400 MPa and sintered conventionally at 1400, 1430 and 1450 degrees C for 2 h. In order to improve the sintering behavior of the cordierite powders, spark-plasma sintering (SPS) was applied. The microstructures and the phase composition of the obtained cordierite materials were analyzed using scanning electron microscopy (SEM) and X-ray diffraction analysis and the mechanical properties of the materials were determined. It was shown that the sinterability of the colloidal powders was much better than that of the alkoxide powders. Conventional sintering at 1400 degrees C of the crystalline powder produced by the colloidal method gave the material of the best mechanical properties. The sinterability of the crystalline alkoxide cordierite powder was highly improved by spark-plasma sintering at a lower sintering temperature (1350 degrees C), for a very short period of tithe (7 min). The density of the obtained material was very close to the theoretical density of alpha-cordierite and the mechanical properties were better than those of materials obtained by conventional sintering.",
publisher = "Elsevier Sci Ltd, Oxford",
journal = "Ceramics International",
title = "Conventional and spark-plasma sintering of cordierite powders synthesized by sol-gel methods",
pages = "5854-5845",
number = "5",
volume = "39",
doi = "10.1016/j.ceramint.2012.12.101"
}

El-Buaishi, N. M., Veljović, Đ., Jokić, B., Radovanović, Ž., Steins, I., Janaćković, Đ.,& Petrović, R.. (2013). Conventional and spark-plasma sintering of cordierite powders synthesized by sol-gel methods. in Ceramics International
Elsevier Sci Ltd, Oxford., 39(5), 5845-5854.
https://doi.org/10.1016/j.ceramint.2012.12.101

El-Buaishi NM, Veljović Đ, Jokić B, Radovanović Ž, Steins I, Janaćković Đ, Petrović R. Conventional and spark-plasma sintering of cordierite powders synthesized by sol-gel methods. in Ceramics International. 2013;39(5):5845-5854.
doi:10.1016/j.ceramint.2012.12.101 .

El-Buaishi, Nozhat Moftah, Veljović, Đorđe, Jokić, Bojan, Radovanović, Željko, Steins, Ints, Janaćković, Đorđe, Petrović, Rada, "Conventional and spark-plasma sintering of cordierite powders synthesized by sol-gel methods" in Ceramics International, 39, no. 5 (2013):5845-5854,
https://doi.org/10.1016/j.ceramint.2012.12.101 . .

TY  - JOUR
AU  - El-Buaishi, Nozhat Moftah
AU  - Janković-Častvan, Ivona
AU  - Jokić, Bojan
AU  - Veljović, Đorđe
AU  - Janaćković, Đorđe
AU  - Petrović, Rada
PY  - 2012
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2199
AB  - The purpose of the research was to investigate crystallization behavior and sintering of cordierite synthesized by a low-price aqueous sol gel route starting from silicic acid and magnesium and aluminum salts. Viscous sintering of the gel occurred in the temperature range of 800-850 degrees C, followed by mu-cordierite crystallization at about 900 degrees C, which proves the homogeneity of the gel. Decreasing of mu-cordierite crystallinity in a wide temperature range prior to commencing of alpha-cordierite crystallization at about 1200 degrees C indicates reconstructive type of mu- - gt  alpha-cordierite transformation. The transformation was fully completed at 1350 degrees C. The value of the Avrami parameter indicates that mu-cordierite crystallization was controlled by surface or interface nucleation, which implies that viscous sintering occurred in the primary gel particles, which leads to shrinkage, and thereafter nucleation occurred on the surface or interface of the particles. The overall activation energy of mu-cordierite crystallization was 382.0 kJ/mol. The sinterability of the powder obtained by calcination at 1300 degrees C, where well-crystallized alpha-cordierite was formed, was better than that of the powder obtained by calcination at 850 degrees C, where the most intensive shrinkage occurred before the onset of crystallization of mu-cordierite.
PB  - Elsevier Sci Ltd, Oxford
T2  - Ceramics International
T1  - Crystallization behavior and sintering of cordierite synthesized by an aqueous sol-gel route
EP  - 1841
IS  - 3
SP  - 1835
VL  - 38
DO  - 10.1016/j.ceramint.2011.10.008
ER  - 

@article{
author = "El-Buaishi, Nozhat Moftah and Janković-Častvan, Ivona and Jokić, Bojan and Veljović, Đorđe and Janaćković, Đorđe and Petrović, Rada",
year = "2012",
abstract = "The purpose of the research was to investigate crystallization behavior and sintering of cordierite synthesized by a low-price aqueous sol gel route starting from silicic acid and magnesium and aluminum salts. Viscous sintering of the gel occurred in the temperature range of 800-850 degrees C, followed by mu-cordierite crystallization at about 900 degrees C, which proves the homogeneity of the gel. Decreasing of mu-cordierite crystallinity in a wide temperature range prior to commencing of alpha-cordierite crystallization at about 1200 degrees C indicates reconstructive type of mu- - gt  alpha-cordierite transformation. The transformation was fully completed at 1350 degrees C. The value of the Avrami parameter indicates that mu-cordierite crystallization was controlled by surface or interface nucleation, which implies that viscous sintering occurred in the primary gel particles, which leads to shrinkage, and thereafter nucleation occurred on the surface or interface of the particles. The overall activation energy of mu-cordierite crystallization was 382.0 kJ/mol. The sinterability of the powder obtained by calcination at 1300 degrees C, where well-crystallized alpha-cordierite was formed, was better than that of the powder obtained by calcination at 850 degrees C, where the most intensive shrinkage occurred before the onset of crystallization of mu-cordierite.",
publisher = "Elsevier Sci Ltd, Oxford",
journal = "Ceramics International",
title = "Crystallization behavior and sintering of cordierite synthesized by an aqueous sol-gel route",
pages = "1841-1835",
number = "3",
volume = "38",
doi = "10.1016/j.ceramint.2011.10.008"
}

El-Buaishi, N. M., Janković-Častvan, I., Jokić, B., Veljović, Đ., Janaćković, Đ.,& Petrović, R.. (2012). Crystallization behavior and sintering of cordierite synthesized by an aqueous sol-gel route. in Ceramics International
Elsevier Sci Ltd, Oxford., 38(3), 1835-1841.
https://doi.org/10.1016/j.ceramint.2011.10.008

El-Buaishi NM, Janković-Častvan I, Jokić B, Veljović Đ, Janaćković Đ, Petrović R. Crystallization behavior and sintering of cordierite synthesized by an aqueous sol-gel route. in Ceramics International. 2012;38(3):1835-1841.
doi:10.1016/j.ceramint.2011.10.008 .

El-Buaishi, Nozhat Moftah, Janković-Častvan, Ivona, Jokić, Bojan, Veljović, Đorđe, Janaćković, Đorđe, Petrović, Rada, "Crystallization behavior and sintering of cordierite synthesized by an aqueous sol-gel route" in Ceramics International, 38, no. 3 (2012):1835-1841,
https://doi.org/10.1016/j.ceramint.2011.10.008 . .