Analysis on the amplitude of serrated flow associated with the Portevin-LeChatelier effect of substitutional fcc alloys

M. C. Chen, L. H. Chen, T. S. Lui

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12 Citations (Scopus)

Abstract

The serration of flow curve is a common feature of the Portevin-LeChatelier effect of substitutional fee alloys. Under the condition that the onset strain of serration decreases with increasing temperature, previous experimental results have shown that the serration stress amplitude, Δσ-, increases with increasing strain (ε) and temperature (T); it decreases with increasing grain size (d) and strain rate (ε). A conventional rationalization assumes that Δσ is proportional to the number of solute atoms, N, in dislocation atmospheres, where N is a function of the diffusion coefficient, aging time, and temperature. By adopting this approach and taking into account the effects of strain rate, strain, and grain size, the relation Δ7sigma; ∝ [ε-1 εβ(1/2 + γ) d-n(1/2 + γ) T-1 exp (-Q/kT)]2/3 is proposed, where Q is the activation energy associated with substitutional diffusion. The proposed model fits well with the experimental data of an Al-3.7 wt pet Mg alloy.

Original languageEnglish
Pages (from-to)1691-1694
Number of pages4
JournalMetallurgical and Materials Transactions A: Physical Metallurgy and Materials Science
Volume27
Issue number6
DOIs
Publication statusPublished - 1996 Jan 1

All Science Journal Classification (ASJC) codes

  • Condensed Matter Physics
  • Mechanics of Materials
  • Metals and Alloys

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