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Effect of High‐Energy Ball Milling and Silica Fume Addition in BaCO 3 – Al 2 O 3 . Part I: Formation of Cementing Phases
Author(s) -
Kumar Pattem Hemanth,
Srivastava Abhinav,
Kumar Vijay,
Kumar Pradeep,
Singh Vinay Kumar
Publication year - 2014
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/jace.13173
Subject(s) - materials science , calcination , ball mill , aluminate , barium , chemical engineering , amorphous solid , mineralogy , phase (matter) , metallurgy , chemistry , crystallography , cement , biochemistry , engineering , catalysis , organic chemistry
The effects of high‐energy ball milling and subsequent calcination on the formation of barium aluminate cementing phases using mixtures of Al 2 O 3 and BaCO 3 were investigated. Silica fume was further added in the raw mixtures to observe its role on the cementing phase formation. Results indicated that the decomposition temperature of BaCO 3 lowered remarkably with the increase in milling time. Barium aluminate cements with grain size in nanometer range were obtained from high‐energy ball‐milled raw mixtures. X‐ray diffraction ( XRD ) results confirmed several crystalline barium‐silicate and barium aluminate phases present. Formation of crystalline BaO · Al 2 O 3 phase was observed between 1000°C and 1100°C in the raw mixtures, which were obtained in amorphous state after milling for 5 h. This temperature is at least 300°C lower than that used in the traditional solid‐state method. Fume SiO 2 additions resulted in BaO · Al 2 O 3 ·2 SiO 2 (celsian) formation which acted as a retarder, provides more workability and mechanical strength.