Enhancement of fatigue crack growth and fracture resistance in Ti--6Al--4V and Ti--6Al--6V--2Sn through microstructural modification

Technical Report · Wed Nov 24 04:00:00 EST 1976

OSTI ID:7328663

Yoder, G R; Cooley, L A; Crooker, T W

Significant enhancement of fatigue crack propagation resistance and plane-strain fracture toughness was obtained in commercial-purity Ti--6Al--4V and Ti--6Al--6V--2Sn by microstructural modification. These alloys were studied in 25.4-mm-thick plates with interstitial oxygen contents of 0.20 and 0.17 wt%, respectively. Heat treatments were chosen to provide widely varied microstructures; they were a mill anneal, a recrystallization anneal, and a beta anneal. The beta anneal was found to be best for improving the crack tolerance properties in question, but it reduced yield strength 9-14% from levels associated with the original mill anneal. The recrystallization anneal significantly enhanced plane-strain fracture toughness and marginally improved fatigue crack propagation resistance with negligible loss of yield strength. 10 tables, 8 fig.

• Research Organization: Naval Research Lab., Washington, DC (USA)
• OSTI ID: 7328663
• Report Number(s): NRL-8049
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360103* -- Metals & Alloys-- Mechanical Properties
ALLOYS
ALUMINIUM ALLOYS
ANNEALING
CRACKS
CRYSTAL STRUCTURE
FATIGUE
FRACTURE PROPERTIES
HEAT TREATMENTS
MECHANICAL PROPERTIES
MICROSTRUCTURE
PLATES
RECRYSTALLIZATION
TIN ALLOYS
TITANIUM ALLOYS
TITANIUM BASE ALLOYS
VANADIUM ALLOYS
YIELD STRENGTH