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The effect of TiO 2 additions on CaO–MgO–Al 2 O 3 –SiO 2 ( CMAS ) crystallization behavior from the melt
Author(s) -
Webster Rebekah I.,
Opila Elizabeth J.
Publication year - 2019
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.16180
Subject(s) - crystallization , aluminosilicate , differential scanning calorimetry , materials science , melilite , scanning electron microscope , diopside , anorthite , chemical engineering , mineralogy , analytical chemistry (journal) , calcium aluminosilicate , energy dispersive x ray spectroscopy , metallurgy , chemistry , composite material , thermodynamics , organic chemistry , engineering , physics , spinel , catalysis
Titania (TiO 2 ) was introduced into a model calcium‐magnesium aluminosilicate ( CMAS ) glass in additions of 5‐20 wt%. The crystallization behavior of the mixtures was characterized over a series of temperature profiles and compared to that of CMAS alone. X‐ray diffraction, differential scanning calorimetry, light and scanning electron microscopy, and energy dispersive spectroscopy were used to characterize glass and crystalline products. Titania additions in the amount of approximately 12.5‐20 wt% aided in the formation of CaTiO 3 from melts equilibrated at either 1300 or 1500°C and cooled at 10°C/min. Holding CMAS + TiO 2 (TiO 2 ≥ 10 wt%) at 900°C after cooling from 1300/1500°C resulted in the formation of additional crystalline phases including melilite, paqueite, and diopside. Implications for CMAS interactions with thermal and environmental barrier coatings are discussed.