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Low‐temperature oxidation‐induced crack healing in Ti 2 Al 0.5 Sn 0.5 C–Al 2 O 3 composites
Author(s) -
Bei Guoping,
Mačković Mirza,
Spiecker Erdmann,
Greil Peter
Publication year - 2019
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.13315
Subject(s) - materials science , scanning electron microscope , annealing (glass) , composite material , composite number , transmission electron microscopy , volume fraction , microstructure , energy dispersive x ray spectroscopy , nanotechnology
The oxidation‐induced crack healing of an Al 2 O 3 composite loaded with various volume fractions of Ti 2 Al 0.5 Sn 0.5 C repair filler particles was investigated by annealing in air at a relatively low temperature of 700°C. After annealing a composite with 20 vol.% repair fillers (with a particle size of ~5.6 µm) for 48 hours, artificial indentation cracks prepared on the surface, as well as pores near the surface, were completely healed by filling with condensed oxidation products. Additionally, minor fraction of metallic Sn was detected. A complementary study by X‐ray diffraction, transmission electron microscopy, scanning electron microscopy, and energy dispersive X‐ray spectroscopy revealed that nano‐sized oxidation products (SnO 2 , TiO 2 , and α‐Al 2 O 3 phase) were formed as major crack‐filling species. After healing, the strength recovery of the Al 2 O 3 composites was significantly improved in the composites loaded with more than 10 vol.% repair fillers and achieved 107% at 700 for 48 hours.