Independent and combined roles of trace Mg and Ag additions in properties precipitation process and precipitation kinetics of Al-Cu-Li-(Mg)-(Ag)-Zr-Ti alloys

Journal Article · Fri Jul 24 04:00:00 EDT 1998 · Acta Materialia

DOI:https://doi.org/10.1016/S1359-6454(98)00079-2· OSTI ID:634675

Huang, B P; Zheng, Z Q ^[1]

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1. Central South Univ. of Technology, Changsha (China). Dept. of Materials Science and Engineering

The independent and combined roles of trace Mg and Ag additions in properties and precipitation of Al-Cu-Li-(Mg)-(Ag)-Zr-Ti alloys were studied. The independent roles of Mg additions are to promote the T{sub 1} precipitation, decrease activation energy for the growth of {theta}{prime} plates and reduce lengthening rates of T{sub 1} and {theta}{prime} plates. The independent roles of Ag additions are to retard GP-zone formation, stimulate the T{sub 1} precipitation and enhance the lengthening rates of T{sub 1} and {theta}{prime} plates. The combined additions of Mg and Ag augment and accelerate the nucleation of T{sub 1} phases. The potent role of independent Mg additions in promoting the precipitation of {theta}{prime} is still effective in the presence of Ag, but it is weakened due to the strong interaction of Mg with Ag. The role of Ag as a stimulus in the lengthening of {theta}{prime} plates is diminished in the presence of Mg additions. The growth of T{sub 1} is controlled by Cu solute diffusion along dislocations regardless of alloy contents of Mg and Ag. The growth of {theta}{prime} plates in the Ag-free alloy is controlled by vacancy-assisted diffusion of Cu.

• OSTI ID: 634675
• Journal Information: Acta Materialia, Journal Name: Acta Materialia Journal Issue: 12 Vol. 46; ISSN 1359-6454; ISSN ACMAFD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
COPPER ALLOYS
LITHIUM ALLOYS
MAGNESIUM ADDITIONS
METALLURGICAL EFFECTS
MICROSTRUCTURE
PRECIPITATION
SILVER ADDITIONS
TITANIUM ALLOYS
ZIRCONIUM ALLOYS