Premium
Subcritical crack growth behavior of a perovskite‐structured Ba 0.5 Sr 0.5 Co 0.8 Fe 0.2 O 3−δ oxygen transport membrane
Author(s) -
Wang Li,
Dou Rui,
Wang Gong,
Li Yizhe,
Bai Mingwen,
Hall David,
Chen Ying
Publication year - 2017
Publication title -
international journal of applied ceramic technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.4
H-Index - 57
eISSN - 1744-7402
pISSN - 1546-542X
DOI - 10.1111/ijac.12768
Subject(s) - materials science , perovskite (structure) , stress (linguistics) , bending , diagram , composite material , fracture (geology) , thermodynamics , analytical chemistry (journal) , crystallography , physics , chemistry , statistics , philosophy , linguistics , mathematics , chromatography
Abstract This paper herein studies subcritical crack growth ( SCG ) behavior of a perovskite‐structured Ba 0.5 Sr 0.5 Co 0.8 Fe 0.2 O 3−δ ( BSCF ) as an oxygen transport membrane material. The SCG behavior of BSCF is evaluated by a constant load method and constant stress rate method at room temperature ( RT ) and 800°C in air, respectively. The low crack velocity measurements are carried out by ring‐on‐ring bending tests while the high crack velocity measurements by compact tension tests. The stress rates vary approximately from 0.1012 to 101.2 MP a/min. The fracture stress increases with increasing stress rate at 800°C. The SCG parameter, n, of BSCF is determined to be 24.32 and 13.83 at RT and 800°C in air, respectively. This indicates that BSCF is more susceptible to SCG at 800°C. The strength‐probability‐time ( SPT ) diagram is constructed for design proposes. The stress for a lifetime of 40 years should not exceed 27.21 MP a at RT or 4.53 MP a at 800°C to assure a failure probability below 1%.