Effect of two-stage strain-rate test on the superplastic behavior of an Al-Li-Cu-Mg-Zr alloy; Microstructural characterization

Journal Article · Tue Jan 01 04:00:00 EST 1991 · Scripta Metallurgica; (United States)

DOI:https://doi.org/10.1016/0956-716X(91)90364-7· OSTI ID:5343901

Liu, Q ^[1]; Yang, J; Yao, M ^[2]

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1. Analysis and Measurement Centre, Harbin Inst. of Technology, Harbin 150006 (CN)
2. Dept. of Metals and Technology, Harbin Inst. of Technology, Harbin 150006 (CN)

The effect of two-stage strain rate tests on the mechanical behavior of a warm-rolled Al-Li-Cu-Mg-Zr alloy during superplastic deformation has been studied. The results showed that a two-stage strain rate test produces much higher elongation than that of single strain rate tests. The optimum deformation parameters correspond to the proper combination of strain rate hardening and strain hardening during the second stage of superplastic deformation. The paper examines the effect of two-stage strain rate tests on microstructural changes during superplastic deformation of an Al-Li-Cu-Mg-Zr alloy, and relates these changes to the superplasticity, as well as the effect of the first stage strain rate on the deformation-induced recrystallized grain size and the conversion rate from the subgrain structure to the high angle grain boundary structure. The results show that the higher first stage strain rate results in a faster deformation-induced recrystallization rate and a finer recrystallized grain size. The microstructure formed using the optimum first stage deformation parameters is characterized by stable fine recrystallized grains and less cavitation. Both a higher first stage strain rate and first stage strain may result in severe cavitation. The grain growth of the fine grains results in high strain hardening, necking resistance and great elongations during the second stage low strain rate deformation.

• OSTI ID: 5343901
• Journal Information: Scripta Metallurgica; (United States), Journal Name: Scripta Metallurgica; (United States) Vol. 25:1; ISSN 0036-9748; ISSN SCRMB
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102* -- Metals & Alloys-- Structure & Phase Studies
360103 -- Metals & Alloys-- Mechanical Properties
ALLOYS
ALUMINIUM ALLOYS
CHEMICAL REACTION KINETICS
COPPER ALLOYS
CRYSTAL STRUCTURE
GRAIN BOUNDARIES
HEAT RESISTANT MATERIALS
HEAT RESISTING ALLOYS
KINETICS
LITHIUM ALLOYS
MAGNESIUM ALLOYS
MATERIALS
MECHANICAL PROPERTIES
MICROSTRUCTURE
PLASTICITY
REACTION KINETICS
RECRYSTALLIZATION
ZIRCONIUM ALLOYS