Fatigue crack propagation in single-crystal CMSX-2 at elevated temperature

Journal Article · Sun Aug 01 00:00:00 EDT 1993 · Journal of Materials Engineering and Performance; (United States)

DOI:https://doi.org/10.1007/BF02661731· OSTI ID:5448043

Antolovich, B F; Saxena, A ^[1]; Antolovich, S D ^[2]

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1. Georgia Inst. of Tech., Atlanta, GA (United States). School of Materials Science and Engineering
2. Washington State Univ., Pullman, WA (United States). Dept. of Mechanical and Materials Engineering

The fatigue crack propagation (FCP) behavior of the nickel-base superalloy CMSX-2 in single-crystal form was investigated. Tests were conducted for two temperatures (25 and 700 C), two orientations ([001][110] and [001][010]), and in two environments (laboratory air and ultra-high vacuum 10[sup [minus]7] torr). Following FCP testing, the fracture surfaces were examined using scanning electron microscopy (SEM). The FCP rates were found to be relatively independent of the temperature, environment, and orientation when correlated with the conventional mode 1 stress-intensity factor. Examination of the fracture surfaces revealed two distinct types of fracture. One type was characterized by [111] fracture surfaces, which were inclined relative to both the loading and crack propagation directions. These features, although clearly a result of the fatigue process, resembled cleavage fractures along [111] planes. Such features were observed at 25 and 700 C; they were the only features observed for the 25 C tests. The second type had a macroscopically dull loading appearance, was microscopically rough, and grew normal to the loading axis. These features were observed on the specimens tested at 700 C (in both air and vacuum) and appeared similar to conventional fatigue fractures. Although in this region the crack plane was macroscopically normal to the loading direction, it deviated microscopically to avoid shearing the [gamma][prime] precipitates.

• OSTI ID: 5448043
• Journal Information: Journal of Materials Engineering and Performance; (United States), Journal Name: Journal of Materials Engineering and Performance; (United States) Vol. 2:4; ISSN 1059-9495; ISSN JMEPEG
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360103* -- Metals & Alloys-- Mechanical Properties
ALLOYS
CRACK PROPAGATION
DATA
ENGINES
EXPERIMENTAL DATA
GAS TURBINE ENGINES
GRAIN ORIENTATION
HEAT ENGINES
HEAT RESISTANT MATERIALS
HEAT RESISTING ALLOYS
INFORMATION
INTERNAL COMBUSTION ENGINES
LIFETIME
MATERIALS
MATERIALS TESTING
MECHANICAL TESTS
MICROSTRUCTURE
NICKEL ALLOYS
NICKEL BASE ALLOYS
NUMERICAL DATA
ORIENTATION
SERVICE LIFE
TESTING