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
- 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, Vol. 46, Issue 12; Other Information: PBD: 24 Jul 1998
- Country of Publication:
- United States
- Language:
- English
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