Structural Irreversibility and Enhanced Brittleness under Fatigue in Zr-Based Amorphous Solids

Metals

Peng Tong⁴  Despina Louca⁴  Gongyao Wang⁶  Peter K. Liaw⁶  Yoshihiko Yokoyama²  Anna Llobet³  Hiroshi Kawaji¹  Yiming Qiu⁵ 

[1] Materials and Structures Laboratory, Tokyo Institute of Technology, 4259-R3-8 Nagatsuta-cho, Midori-ku, Yokohama 226-8503, Japan; E-Mail:;Institute of Materials Research, Tohoku University, Sendai 980-8577, Japan; E-Mail:;Los Alamos National Laboratory, Lujan Neutron Scattering Center, Los Alamos, NM 87545, USA; E-Mail:;Department of Physics, University of Virginia, VA 22904, USA;NIST center for Neutron Research, Gaithersburg, MD 20899, USA and Department of Materials Science and Engineering, University of Maryland, College Park, MD 20742, USA; E-Mail:;Department of Materials Science and Engineering, The University of Tennessee, Knoxville, TN 37831, USA; E-Mails:

关键词: local structure;    compression fatigue;    dynamics;    VDOS attenuation;   

DOI  :  10.3390/met2040529

来源: mdpi

【 摘 要 】

The effect of fatigue on ZrCuAl amorphous metals induced by mechanical cyclic loading is investigated using inelastic neutron scattering and the pair density function analysis of neutron diffraction data. With cooling, the local atomic structure undergoes reorganization under fatigue that is directly related to the number of fatigue cycles. Also under fatigue, suppression in the atomic dynamics is observed as well. A structural restructuring occurs within a 4 Å radius and intensifies with increasing the compression cycles, whereas the vibrational density of states is attenuated as the intensity shifts towards the elastic, zero-energy transfer peak. The combined static and dynamic structural effects are a signature of the microscopic changes brought about by fatigue, and together may be the onset for subsequent behaviors following extended cyclic loading such as fracture. Even after the load is removed, the structural changes described here remain and increase with repeated cyclic loading which is an indication that the lattice deforms even before shear bands are formed.

【 授权许可】

CC BY   
© 2012 by the authors; licensee MDPI, Basel, Switzerland.