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Corrosion Behavior of Single‐Crystal Alumina in Argon, Air, and Water Vapor Atmospheres at 1700‐2000°C
Author(s) -
Yue XueMei,
Zhang GuoJun,
Watanabe Tadahiko,
Tai WeonPil
Publication year - 1999
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.1151-2916.1999.tb02122.x
Subject(s) - corrosion , argon , water vapor , materials science , metallurgy , impurity , crystal (programming language) , composite material , chemistry , organic chemistry , computer science , programming language
The results for the corrosion of alumina single crystals at 1700‐2000°C in argon, argon/water vapor, air, and air/water vapor for 10 h are reported. There were no obvious weight and volume changes after corrosion. White spots were observed on the surfaces of the specimens after corrosion tests. The initial temperature for the appearance of these white spots was 1800°C for argon and air, 1900°C for argon/water vapor, and 2000°C for air/water vapor. These white spots were likely formed by internal impurities, which diffused outward to the surface and coalesced at high temperatures. There was no evidence of corrosion damage inside the specimens. The flexural strength of the specimens was clearly enhanced after the corrosion tests and showed no evident relation to the corrosion conditions. This increase in strength after corrosion was likely due to the healing of surface machining flaws. The surface flaw healing temperature for alumina crystals was higher than 1400°C.