Fatigue crack nucleation in metallic materials

Technical Report · Thu Apr 01 04:00:00 EST 1999

DOI:https://doi.org/10.2172/334214· OSTI ID:334214

Peralta, P ^[1]; Laird, C ^[2]; Ramamurty, U ^[3]; Suresh, S ^[4]; Campbell, G H; King, W E ^[5]; Mitchell, T E ^[6]

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1. Arizona State Univ., Tempe, AZ (United States). Dept. of Mechanical and Aerospace Engineering
2. Univ. of Pennsylvania, Philadelphia, PA (United States). Dept. of Materials Science and Engineering
3. Nanyang Technological Univ. (Singapore). School of Mechanical and Production Engineering
4. Massachusetts Inst. of Tech., Cambridge, MA (United States). Dept. of Materials Science and Engineering
5. Lawrence Livermore National Lab., CA (United States)
6. Los Alamos National Lab., NM (United States). Center for Materials Science

The process of fatigue crack nucleation in metallic materials is reviewed placing emphasis in results derived for pure FCC metals with wavy slip behavior. The relationship between Persistent Slip Bands (PSB`s) and crack initiation will be examined for both single crystals and polycrystals, including the conditions for inter- and transgranular crack nucleation and their connection to type of loading, crystallography and slip geometry. The latter has been found to be an important parameter in the nucleation of intergranular cracks in polycrystals subjected to high strain fatigue, whereby primary slip bands with long slip lengths impinging on a grain boundary produce intergranular crack nucleation under the right conditions. Recent results related to intergranular crack nucleation in copper bicrystals and crack nucleation in Cu/Sapphire interfaces indicate that this mechanism controls crack nucleation in those simpler systems as well. Furthermore, it is found that under multiple slip conditions the crack nucleation location is controlled by the presence of local single slip conditions and long slip lengths for a particular Burgers vector that does not have to be in the primary slip system.

• Research Organization: Los Alamos National Lab., NM (United States)
• Sponsoring Organization: USDOE Office of Energy Research, Washington, DC (United States)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 334214
• Report Number(s): LA-UR--99-594; CONF-981216--; ON: DE99002227
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
COMPOSITE MATERIALS
COPPER
CRACKS
EXPERIMENTAL DATA
FATIGUE
FRACTURE PROPERTIES
NUCLEATION
SAPPHIRE
SLIP
STRAINS