TY - JOUR
T1 - Variation in viscosity of aluminosilicate melts with MgO/CaO molar ratio
T2 - Influence of five-fold coordinated aluminum
AU - Kim, Kyung Ho
AU - Sukenaga, Sohei
AU - Tashiro, Masanori
AU - Kanehashi, Koji
AU - Yoshida, Sinichiro
AU - Shibata, Hiroyuki
N1 - Funding Information:
This work was supported in-part by JSPS KAKENHI (Grant Number 19K05106) and the Dynamic Alliance for Open Innovation Bridging Human, Environment and Materials from the Ministry of Education, Culture, Sports, Science and Technology of Japan (MEXT).
Publisher Copyright:
© 2022
PY - 2022/7/1
Y1 - 2022/7/1
N2 - Viscosity of aluminosilicate melts is important for estimating transport phenomena in industrial processes. Viscosity variations with increasing MgO/CaO molar ratio have been reported for CaO–MgO–SiO2 (CMS) and CaO–MgO–Al2O3–SiO2 (CMAS) systems; however, the viscosity variation was not clearly correlated with the change in the melt structure. The present study investigated the influence of the MgO/CaO molar ratio on the viscosity of CMAS melts at temperatures higher than the liquidus using the rotating crucible method. The viscosity decreased with increasing substitution of CaO by MgO in the chosen CMAS system, whereas the opposite behavior has been reported for the CMS system. Aluminum-27 magic-angle spinning nuclear magnetic resonance spectra of the CMAS glasses show that the fraction of aluminum atoms in five-fold coordination ([5]Al) increased with increasing substitution of CaO by MgO. Our findings indicate that the formation of [5]Al reduces the viscosity of aluminosilicate melts.
AB - Viscosity of aluminosilicate melts is important for estimating transport phenomena in industrial processes. Viscosity variations with increasing MgO/CaO molar ratio have been reported for CaO–MgO–SiO2 (CMS) and CaO–MgO–Al2O3–SiO2 (CMAS) systems; however, the viscosity variation was not clearly correlated with the change in the melt structure. The present study investigated the influence of the MgO/CaO molar ratio on the viscosity of CMAS melts at temperatures higher than the liquidus using the rotating crucible method. The viscosity decreased with increasing substitution of CaO by MgO in the chosen CMAS system, whereas the opposite behavior has been reported for the CMS system. Aluminum-27 magic-angle spinning nuclear magnetic resonance spectra of the CMAS glasses show that the fraction of aluminum atoms in five-fold coordination ([5]Al) increased with increasing substitution of CaO by MgO. Our findings indicate that the formation of [5]Al reduces the viscosity of aluminosilicate melts.
KW - Alkaline-earth aluminosilicate melts and glasses
KW - Aluminum-27 MAS NMR
KW - CaO–MgO–AlO–SiO (CMAS)
KW - Structure
KW - Viscosity
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U2 - 10.1016/j.jnoncrysol.2022.121600
DO - 10.1016/j.jnoncrysol.2022.121600
M3 - Article
AN - SCOPUS:85127712065
SN - 0022-3093
VL - 587
JO - Journal of Non-Crystalline Solids
JF - Journal of Non-Crystalline Solids
M1 - 121600
ER -