Cyclic response of ultrafine-grained copper at constant plastic strain amplitude
- Kanazawa Univ. (Japan). Dept. of Mechanical Systems Engineering
- Kyoto Univ. (Japan). Dept. of Engineering Physics and Mechanics
- Ufa State Aviation Technical Univ. (Russian Federation). Inst. of Physics of Advanced Materials
The mechanical properties of ultrafine grained (UFG) materials (nanocrystals and submicrocrystalline metals and alloys) have been a subject of growing interest in the last few years. This is largely due to a promising combination of their high mechanical characteristics such as a yield stress and hardness with fairly large plasticity which makes these materials attractive for practical purposes. The first results on fatigue of nanocrystalline copper produced by compaction were recently reported by Witney et al. The fatigue experiments were conducted with the aim of investigating the stability of the internal structure under repeated compressive loading. However, it is generally believed that the development of microstructure in fatigue is primarily due to the to-and-fro motion of dislocations. In this sense, cyclic tension/compression tests seem to be appropriate for the investigation of essential fatigue properties such as cyclic hardening and the Bauschinger effect. The study of both these properties is supposed to shed some light on the mechanisms of deformation of UFG materials. For this purpose the authors examine a cyclic response of UFG copper under fully reversible loading at relatively low plastic strain amplitudes. The main feature of UFG materials prepared by severe plastic deformation is that the grains are separated by high-angle non-equilibrium grain boundaries (GBs) having long range stress fields. The present work is directed, in particular, towards further understanding of the role of GBs in the properties of UFG materials.
- OSTI ID:
- 509170
- Journal Information:
- Scripta Materialia, Journal Name: Scripta Materialia Journal Issue: 11 Vol. 36; ISSN 1359-6462; ISSN SCMAF7
- Country of Publication:
- United States
- Language:
- English
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