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Alumina Volatility in Water Vapor at Elevated Temperatures
Author(s) -
Opila Elizabeth J.,
Myers Dwight L.
Publication year - 2004
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.1551-2916.2004.01701.x
Subject(s) - sapphire , volatilisation , volatility (finance) , water vapor , vapour pressure of water , partial pressure , vapor pressure , analytical chemistry (journal) , oxygen , materials science , enthalpy , chemistry , thermodynamics , environmental chemistry , organic chemistry , optics , laser , physics , financial economics , economics
The volatility of alumina in high‐temperature water vapor was determined by a weight loss technique. Sapphire coupons were exposed at temperatures between 1250° and 1500°C, water partial pressures between 0.15 and 0.68 atm in oxygen, a total pressure of 1 atm, and flowing gas velocities of 4.4 cm/s. The water vapor pressure dependence of sapphire volatility was consistent with Al(OH) 3 ( g ) formation. The enthalpy of reaction to form Al(OH) 3 ( g ) from sapphire and water vapor was determined to be 210 ± 20 kJ/mol, comparing favorably to other studies. Microstructural examination of tested sapphire coupons revealed surface rearrangement consistent with a volatilization process.