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The metallographic characteristics of fatigue cracks in the titanium alloy IMI829 at 400°C and 600°C
Author(s) -
Hamdy M. M.,
Noble B.,
Waterhouse R. B.
Publication year - 1983
Publication title -
journal of microscopy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.569
H-Index - 111
eISSN - 1365-2818
pISSN - 0022-2720
DOI - 10.1111/j.1365-2818.1983.tb04549.x
Subject(s) - microstructure , materials science , alloy , fretting , titanium alloy , metallurgy , tension (geology) , fatigue testing , composite material , ultimate tensile strength
SUMMARY High temperature fatigue tests under fluctuating axial tension were carried out on the alloy in the fully heat treated condition, the microstructure consisting of a β matrix containing colonies of aligned α‐platelets. Fatigue cracks were initiated by fretting at temperatures of 400°C and 600°C. A detailed metallographic examination has been made of the fretted region and the resulting fatigue crack and these characteristics have been related to the microstructure of the alloy. At test temperatures of 400°C the fatigue cracks initially propagated at right angles to the α‐platelets but where their orientation was unfavourable, propagation also occurred parallel to the α‐platelets. At test temperatures of 600°C the initial direction of crack propagation was independent of the microstructure.