Fracture of Ni with grain-size from nanocrystalline to ultrafine scale under cyclic loading

Journal Article · Mon Jan 01 00:00:00 EST 2007 · Scripta Materialia

DOI:https://doi.org/10.1016/j.scriptamat.2007.04.013· OSTI ID:963948

Cheng, Sheng ^[1]; Stoica, Alexandru Dan ^[1]; Wang, Xun-Li ^[1]; Wang, Gy ^[2]; Choo, Hahn ^[1]; Liaw, Peter K ^[2]

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1. ORNL
2. University of Tennessee, Knoxville (UTK)

A two-step fatigue loading scheme was developed to study the fracture characteristics of nanocrystalline and ultrafine-grained Ni, with grain-sizes of 23 and 260nm, respectively. Cyclic work-hardening, measured by the mid-loop width during cycling, was observed in both types of material in the first loading step. The loop width increases rapidly as the load is upgraded in the second step. Crack initiation and striation have been observed for the first time in nanocrystalline Ni.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: DE-AC05-00OR22725
• OSTI ID: 963948
• Journal Information: Scripta Materialia, Vol. 57, Issue 3; ISSN 1359-6462
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
77 NANOSCIENCE AND NANOTECHNOLOGY
NICKEL
FATIGUE
CRACK PROPAGATION
GRAIN SIZE
STRAIN HARDENING
NANOSTRUCTURES