Subsurface Facet-fisheye Induced Failure of Titanium Alloy under Very High Cycle Fatigue
Abstract
Very high cycle fatigue test under pulsating tension was performed to investigate the subsurface failure mechanism of a titanium alloy. A peculiar region, called “facets cluster zone (FCZ)”, is located at the center of fisheye. The slip-like patterns on facet surface, coalescence of nanoscale cracks and growth of microcracks in the maximum shear stress plane are observable. Combined with the evaluation of stress intensity factors at crack tips, the subsurface failure processes are summarized as: (a) localization of plastic strain, (b) occurrence of slip lines, (c) nucleation of microcracks, (d) coalescence and growth of microcracks, (f) occurrence of the FCZ, (g) formation of fisheye and (i) unstable crack growth until final fracture.
- Publication:
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Materials Science and Engineering Conference Series
- Pub Date:
- January 2020
- DOI:
- 10.1088/1757-899X/746/1/012017
- Bibcode:
- 2020MS&E..746a2017L