Stress corrosion cracking facet crystallography of Ti–8Al–1Mo–1V

The spatial and crystallographic orientations of facets formed during stress corrosion cracking of Ti–8Al–1Mo–1V have been characterized using quantitative fractography and electron backscatter diffraction. The results indicate that most facets are formed nearly perpendicular to the loading direction on irrational {h k i l} planes. The facets were imaged with high resolution scanning electron microscopy and were found to contain evidence of localized plastic flow despite their “brittle” appearance at moderate magnification. Some fracture planes were related to titanium hydride habit planes, however, the mechanism of faceted growth does not appear to involve hydride nucleation, growth, and fracture, but rather hydrogen enhanced localized plasticity.