Cavitation in the neck of a deformed Ti-47Al-2Nb-2Cr creep specimen

Journal Article · Wed May 15 04:00:00 EDT 1996 · Scripta Materialia

DOI:https://doi.org/10.1016/1359-6462(96)00023-1· OSTI ID:247988

Sneary, P R; Beals, R S; Bieler, T R ^[1]

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1. Michigan State Univ., East Lansing, MI (United States). Dept. of Materials Science and Mechanics

In creep deformation, intergranular cavitation is the predominant damage process that leads to fracture. In addition to the strain rate, nucleation and growth of cavities are the most important issues to examine when considering material lifetimes. Cavities tend to grow on boundaries normal to the tensile stress axis. Constrained cavity growth models describe how the growth rate is retarded due to the need for the surrounding matrix to accommodate the volume increase. Near-{gamma} TiAl has a microstructure that is very sensitive to heat treatment and deformation history. In this study, the authors investigate a necked creep specimen upon which creep rates were evaluated in a history that started with a large stress and steadily decreased by stress changes through the end of the experiment. Since creep rates at similar stresses are as much as an order of magnitude higher than in a specimen deformed in a generally increasing stress change history, the cavitation evident in the neck is expected to be strongly affected by the particular deformation history in the material.

• OSTI ID: 247988
• Journal Information: Scripta Materialia, Journal Name: Scripta Materialia Journal Issue: 10 Vol. 34; ISSN 1359-6462; ISSN XZ503X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
CHROMIUM ALLOYS
CRACKS
DEFORMATION
DIFFUSION
GRAIN BOUNDARIES
INTERMETALLIC COMPOUNDS
NIOBIUM ALLOYS
NUCLEATION
POROSITY
STRAIN RATE
STRESSES
TITANIUM ALLOYS
VACANCIES