|Enhanced cyclic deformation responses of ultrafine-grained Cu and nanocrystalline Cu-Al alloys|
|X. H. An; S. D. Wu; Z. G. Wang; Z. F. Zhang
|Source Publication||Acta Materialia
|Abstract||Cyclic deformation responses of ultrafine-grained (UFG) Cu and nanocrystalline (NC) Cu Al alloys produced by equal channel angular pressing were investigated systematically by applying low-cycle fatigue (LCF) and high-cycle fatigue (HCF) tests. Based on the dependence of the fatigue life (N-f) on the total strain amplitude (Delta epsilon(t)/2) and stress amplitude (Delta sigma/2) in comparison with that of UFG Cu, the LCF life and HCF strength, especially fatigue endurance limits, of NC Cu Al alloys, were enhanced strikingly at the same time as their stacking fault energies (SFE) decreased. These upgraded fatigue performances with lowering of the SFE in NC Cu Al alloys can be attributed not only to the simultaneous increase in their monotonic strength and ductility on the macroscale, but also to the crucially decreased cyclic softening behavior on the microscale. It was found that substantial grain growth and large-scale shear bands, both of which are essential ingredients, resulting in significant cyclic softening and then deterioration in the LCF life of UFG and NC materials, were reduced advantageously on decreasing the SFE in NC Cu-Al alloys. Moreover, the dominant fatigue damage micro-mechanism was also transformed inherently from extensive grain boundary (GB) migration in UFG Cu to other local GB activities such as atom shuffling or GB sliding/rotation in NC Cu Al alloy with low SFE. (C) 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.|
|description.department||[an, x. h.
; wu, s. d.
; wang, z. g.
; zhang, z. f.] chinese acad sci, inst met res, shenyang natl lab mat sci, shenyang 110016, peoples r china.
; an, xh (reprint author), chinese acad sci, inst met res, shenyang natl lab mat sci, 72 wenhua rd, shenyang 110016, peoples r china.
Nanocrystalline Cu-al Alloys
Fatigue Damage Mechanism
X. H. An,S. D. Wu,Z. G. Wang,et al. Enhanced cyclic deformation responses of ultrafine-grained Cu and nanocrystalline Cu-Al alloys[J]. Acta Materialia,2014,74:200-214.
X. H. An,S. D. Wu,Z. G. Wang,&Z. F. Zhang.(2014).Enhanced cyclic deformation responses of ultrafine-grained Cu and nanocrystalline Cu-Al alloys.Acta Materialia,74,200-214.
X. H. An,et al."Enhanced cyclic deformation responses of ultrafine-grained Cu and nanocrystalline Cu-Al alloys".Acta Materialia 74(2014):200-214.
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