Grain boundary precipitation in Al-Li-Cu alloys. [Al-3%Cu-2%Li and Al-1%Cu-2. 6%Li]

Conference · · TMS (The Metallurgical Society) Paper Selection; (USA)

OSTI ID:5310477

Tosten, M H; Vasudevan, A K; Howell, P R ^[1]

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1. Pennsylvania State Univ., University Park (USA)

Grain Boundary Precipitation in Al-3%Cu-2%Li and Al-l%Cu-2.6%Li alloys has been investigated. It has been found that the equilibrium {Delta} phase precipitates on the high angle boundaries. In addition, a {Delta}{prime} precipitate-free-zone (PFZ) is invariably associated with these boundaries. On the low angle boundaries, the dominant phase is T{sub 1}, although {theta}{prime} has also been observed. On any one planer boundary segment, only one variant of the T{sub 1}, (and/or {theta}{prime}) is observed and this variant is the one which minimizes the angle between the precipitate habit normal and the boundary plane normal. PFZ's were not observed in the vicinity of low angle grain boundaries in the 2.6%Li-1%Cu alloy, but were developed in the 2%Li-3%Cu alloy.

• OSTI ID: 5310477
• Report Number(s): CONF-840909--
• Conference Information: Journal Name: TMS (The Metallurgical Society) Paper Selection; (USA) Journal Volume: 56
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102* -- Metals & Alloys-- Structure & Phase Studies
ALLOYS
ALUMINIUM ALLOYS
ALUMINIUM BASE ALLOYS
CHEMICAL COMPOSITION
COPPER ALLOYS
CRYSTAL STRUCTURE
GRAIN BOUNDARIES
LITHIUM ALLOYS
MICROSTRUCTURE
PHASE STUDIES
PHASE TRANSFORMATIONS
PRECIPITATION
SEPARATION PROCESSES