Growth of surface and corner cracks in beta-processed and mill-annealed Ti-6Al-4V

Technical Report · Tue Jul 01 04:00:00 EDT 1975

OSTI ID:7246548

Bell, P D

Empirical stress-intensity expressions were developed to relate the growth of cracks from corner flaws to the growth of cracks from surface flaws. An experimental program using beta-processed Ti-6Al-4V verified these expressions for stress ratios, R greater than or equal to 0. An empirical crack growth-rate expression which included stress-ratio and stress-level effects was also developed. Cracks grew approximately 10 percent faster in transverse-grain material than in longitudinal-grain material and at approximately the same rate in longitudinal-grain mill-annealed Ti-6Al-4V. Specimens having surface and corner cracks and made of longitudinal-grain, beta-processed material were tested with block loads, and increasing the stresses in a block did not significantly change the crack growth rates. Truncation of the basic ascending stress sequence within a block caused more rapid crack growth, whereas both the descending and low-to-high stress sequences slowed crack growth.

• Research Organization: National Aeronautics and Space Administration, Langley Station, Va. (USA). Langley Research Center
• OSTI ID: 7246548
• Report Number(s): N-75-27135; NASA-TN-D-7922; L-8864
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360103* -- Metals & Alloys-- Mechanical Properties
ALLOYS
ALUMINIUM ALLOYS
CRACKS
DEFECTS
DIAGRAMS
FATIGUE
FRACTURE PROPERTIES
MECHANICAL PROPERTIES
STRESSES
TITANIUM ALLOYS
TITANIUM BASE ALLOYS
VANADIUM ALLOYS