Plastic flow and fatigue behavior of alpha--beta titanium alloys. Annual report No. 1, 1 Apr 75--31 Mar 76. [Ti--6Al--4V and Ti--6Al--2Sn--4Zr--6Mo]

Technical Report · Tue Jun 01 04:00:00 EDT 1976

OSTI ID:7305739

Margolin, H; Mahajan, Y

Void formation, void growth and tensile fracture was studied in ELI Ti--6Al--4V heat treated to strengths of 110 ksi (758 MN/sup 2/) to 140 ksi (965 MN/sup 2/) for both equiaxed and Widmanstatten plus grain boundary alpha structures. Void formation occurred at alpha--matrix interface, at alpha--alpha boundaries and at twin--untwin interfaces within alpha particles. Void growth was found to be a function of microstructure, being more rapid at grain boundary alpha--matrix locations than in equiaxed alpha structures. A plot of corrected fracture stress shows separate curves with about the same slope forequiaxed and grain boundary alpha structures, with the equiaxed alpha structures showing the higher fracture stresses. The dependency of void growth at grain boundaries on grain size and strain hardening rate is discussed. Initial work on low cycle fatigue behavior at constant strain of the Ti--6Al--2Sn--4Zr--6Mo alloy is outlined, and plans for the study of factors controlling the yield strength of alpha--beta Ti alloys are presented. (GRA)

• Research Organization: Polytechnic Inst. of Brooklyn, NY (USA)
• OSTI ID: 7305739
• Report Number(s): AD-A-026609
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360103* -- Metals & Alloys-- Mechanical Properties
ALLOY SYSTEMS
ALLOYS
ALUMINIUM ALLOYS
CRYSTAL STRUCTURE
ELEMENTS
FAILURES
HARDENING
MECHANICAL PROPERTIES
METALS
MICROSTRUCTURE
MOLYBDENUM
REFRACTORY METALS
SIZE
TENSILE PROPERTIES
TIN ALLOYS
TITANIUM ALLOYS
TITANIUM BASE ALLOYS
TRANSITION ELEMENTS
VANADIUM ALLOYS
YIELD STRENGTH
ZIRCONIUM