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

Journal Article · Sun Dec 31 23:00:00 EST 2006 · 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 Laboratory (ORNL)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 963948
• Journal Information: Scripta Materialia, Journal Name: Scripta Materialia Journal Issue: 3 Vol. 57; ISSN 1359-6462; ISSN SCMAF7
• Country of Publication: United States
• Language: English

Related Subjects

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