Superplasticity in a ZK60 magnesium alloy at low temperatures

Journal Article · Fri Jan 22 04:00:00 EST 1999 · Scripta Materialia

DOI:https://doi.org/10.1016/S1359-6462(98)00469-2· OSTI ID:349875

Watanabe, Hiroyuki; Mukai, Toshiji ^[1]; Higashi, Kenji ^[2]

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1. Osaka Municipal Technical Research Inst. (Japan)
2. Osaka Prefecture Univ., Sakai (Japan)

High tensile ductilities associated with superplasticity occur when the grain size is small and typically less than {approximately}10 {micro}m. The conventional superplasticity in pseudo single phase alloys is observed at relatively low strain rate of <10{sup {minus}3} s{sup {minus}1} and at temperatures of {approximately}0.8T{sub m} where T{sub m} is the melting point of the material. Recently, several method have been developed for extreme grain refinement including mechanical alloying, crystallization from amorphous powders, and/or equal-channel-angular-extrusion. Experimental evidence suggests that a reduction in grain size will increase the strain rate and/or decrease the temperature for optimum superplastic flow. The purpose of this paper is to investigate superplastic deformation mechanism at lower temperatures. In this study, mechanical properties in a pseudo single phase magnesium alloy were examined at relatively low homologous temperatures of {approximately}0.5T{sub m}. Based on the constitutive equation for superplastic flow, deformation mechanism at low temperatures is discussed.

• OSTI ID: 349875
• Journal Information: Scripta Materialia, Journal Name: Scripta Materialia Journal Issue: 4 Vol. 40; ISSN 1359-6462; ISSN SCMAF7
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
GRAIN REFINEMENT
MAGNESIUM BASE ALLOYS
PLASTICITY
STRAIN RATE
TEMPERATURE DEPENDENCE