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Low‐Silica Glasses Based on Calcium Aluminates
Author(s) -
ONODA G. Y.,
BROWN S. D.
Publication year - 1970
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/j.1151-2916.1970.tb12114.x
Subject(s) - liquidus , aluminate , materials science , annealing (glass) , mineralogy , quenching (fluorescence) , analytical chemistry (journal) , chemical engineering , composite material , chemistry , cement , alloy , chromatography , engineering , physics , quantum mechanics , fluorescence
An exploratory study of the effects of compositional variation on glass formation in low‐silica aluminate compositions revealed that CaO is essential for glass formation at ordinary quenching rates. Other oxides, such as Li 2 O, MgO, BaO, ZnO, Na 2 O, K 2 O, BeO, B 2 O 3 , and PbO, can be present in the glass in limited amounts (in some cases up to 30 mol%). A necessary, but insufficient, condition for easy glass formation is that the ratio of oxygen ions to network‐forming cations (assumed to be Si 4+ and Al 3+ ) be ∼2.5. The glass‐forming compositions were also characterized by liquidus temperatures below ∼1500°C (2732°F). Young's modulus ranged from 13.0 to 17.8×10 6 psi. Glasses containing network‐modifying cations with high field strengths generally had the higher moduli. Strength (420,000 to 650,000 psi in 0.3‐mil fibers), static fatigue, viscosity, annealing, and surface tension were studied to a limited extent for the composition (in mol%) 30Al 2 O 3 ‐4SiO 2 ‐60CaO‐6MgO.