Long distance roughness of fracture surfaces in heterogeneous materials

Book · Sun Aug 01 04:00:00 EDT 1999

OSTI ID:364069

Hinojosa, M ^[1]; Bouchaud, E ^[2]; Nghiem, B ^[3]

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1. Univ. Autonoma de Neuvo Leon, San Nicolas de los Garza (Mexico)
2. Office Nationale d`Etudes et de Recherches Aerospatiales, Chatillon (France)
3. Lab. CNRS/Saint Gobain, Aubervilliers (France)

The long distance roughness of fatigue fracture surfaces of a nickel-based superalloy is reported for two samples of different grain size. Statistical analysis over a wide range of length scales, from a few nanometers to a few millimeters, using scanning electron microscopy and atomic force microscopy allows to obtain accurately the self-affine correlation length. Long distance fracture profiles of 14,000 points were obtained and digitized from overlapping electron micrographs at a resolution of 0.22 micrometers/point. The authors have also analyzed the long distance roughness of the mirror zone on a soda-lime glass using atomic force microscopy. In the case of the nickel superalloy, correlation lengths are found to correspond well to the grain size. This result gives information about the mechanism of crack propagation in heterogeneous materials and shows that the correlation length of fracture surfaces is of the order of the largest microstructural heterogeneity.

• OSTI ID: 364069
• Report Number(s): CONF-981104--
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CRACK PROPAGATION
EXPERIMENTAL DATA
FATIGUE
FRACTURES
GLASS
GRAIN SIZE
NICKEL BASE ALLOYS
ROUGHNESS