Near-threshold fatigue crack growth phenomena at elevated temperature in titanium alloys. [Ti-4Al, Ti-8Al, and Ti-6242S]

Conference · · TMS (The Metallurgical Society) Paper Selection; (USA)

OSTI ID:5442462

Allison, J E; Williams, J C ^[1]

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1. Carnegie-Mellon Univ., Pittsburgh, PA (USA)

The fatigue crack growth response of three titanium alloys (Ti-4Al, Ti-8Al, and Ti-6242S) has been investigated at 510 C with special emphasis placed on near-threshold growth rates at a load ratio of 0.1. At high delta K, growth rates at 510 C were substantially higher than growth rates determined at room temperature. When experiments were conducted in air, at low delta K all three alloys exhibited an abrupt crack growth arrest phenomenon. An oxide build-up was observed on the fracture surface, which was especially pronounced at the point of crack arrest. For specimens tested in an inert environment or at room temperature this crack arrest phenomenon was not observed. These results suggest the occurrence of an accelerated form of oxide-induced crack closure; this crack closure process and other possible mechanisms are discussed.

• OSTI ID: 5442462
• Report Number(s): CONF-840909--
• Conference Information: Journal Name: TMS (The Metallurgical Society) Paper Selection; (USA) Journal Volume: 56
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360103* -- Metals & Alloys-- Mechanical Properties
AIR
ALLOYS
ALUMINIUM ALLOYS
CHALCOGENIDES
CLOSURES
COATINGS
CRACK PROPAGATION
CRACKS
FATIGUE
FLUIDS
FRACTURE MECHANICS
GASES
INERT ATMOSPHERE
MECHANICAL PROPERTIES
MECHANICS
OXIDES
OXYGEN COMPOUNDS
PROTECTIVE COATINGS
SYNTHESIS
TEMPERATURE DEPENDENCE
TITANIUM ALLOYS
TITANIUM BASE ALLOYS