Influences of strain rate and grain size on yield and serrated flow in commercial Al-Mg alloy 5086

Journal Article · Fri Nov 05 04:00:00 EST 1999 · Scripta Materialia

DOI:https://doi.org/10.1016/S1359-6462(99)00265-1· OSTI ID:20001694

Wagenhofer, M; Erickson-Natishan, M A; Armstrong, R W; Zerilli, F J

Much attention has been paid to the rather special stress-strain characteristics of Al-Mg alloys. Beginning with the pioneering work of Portevin and LeChatelier in 1923, the focus has been on the appearance of tensile band-type deformation markings that are observed coincident with the appearance of serrated flow in stress-strain curves. The serrations are the result of dynamic strain aging (DSA). A major influence of the DSA phenomenon is to produce both a higher flow stress and, very importantly, greater strain hardening at lower strain rates than for higher ones at which serrations do not appear. Physically-based constitutive equations, for example, of Zerilli-Armstrong type, that are derived for thermally-activated dislocation-lattice or dislocation-dislocation interactions, are susceptible to interference from DSA. For this reason, clarification of the importance of strain aging in accounting for laboratory tests of the stress-strain behavior of the alloy has been investigated. Of special interest was the solute influence on the combined yield and strain hardening behavior.

• Research Organization: Univ. of Maryland, College Park, MD (US)
• OSTI ID: 20001694
• Journal Information: Scripta Materialia, Journal Name: Scripta Materialia Journal Issue: 11 Vol. 41; ISSN SCMAF7
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
DISLOCATIONS
FLOW STRESS
GRAIN SIZE
MAGNESIUM ALLOYS
STRAIN AGING
STRAIN RATE
TEMPERATURE DEPENDENCE
YIELD STRENGTH