Creep behavior of a polycrystalline nickel aluminide: Ni-23. 5 at. % Al-0. 5 at. % Hf-0. 2 at. % B

Journal Article · Wed Jan 01 04:00:00 EST 1986 · J. Mat. Res.; (United States)

DOI:https://doi.org/10.1557/JMR.1986.0068· OSTI ID:5774761

Schneibel, J H; Petersen, G F; Liu, C T

The creep behavior of a polycrystalline nickel aluminide with the composition Ni-23.5 at.% Al-0.5 at.% Hf-0.2 at.% B has been measured as a function of stress, temperature, and grain size. At high stresses, of the order of 100 MPa, the strain rate is nonlinear in the stress, with a stress exponent greater than two. Below approximately 10 MPa, at 1033 K, the steady-state strain rate is almost proportional to the stress, indicating that diffusional creep is rate controlling. Calculations of expected Nabarro-Herring and Coble creep rates did not answer whether diffusive mass transport through the grains, or along the grain boundaries, is rate controlling. The grain-size dependence of the strain rate, however, indicates predominance of volume diffusion control, i.e., Nabarro-Herring creep, for our experimental conditions. aluminide

• Research Organization: Metals and Ceramics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 5774761
• Journal Information: J. Mat. Res.; (United States), Journal Name: J. Mat. Res.; (United States) Vol. 1:1; ISSN JMREE
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360103* -- Metals & Alloys-- Mechanical Properties
ALLOYS
ALUMINIUM ALLOYS
ANNEALING
CREEP
CRYSTAL STRUCTURE
GRAIN SIZE
HAFNIUM ADDITIONS
HAFNIUM ALLOYS
HEAT TREATMENTS
HIGH TEMPERATURE
INTERMETALLIC COMPOUNDS
MECHANICAL PROPERTIES
MICROSTRUCTURE
NICKEL ALLOYS
NICKEL BASE ALLOYS
SIZE
STRESSES
TEMPERATURE DEPENDENCE
VERY HIGH TEMPERATURE