Influence of heat treatment and grain shape on exfoliation corrosion of Al-Li alloy 8090

Journal Article · Fri Oct 01 04:00:00 EDT 1993 · Corrosion (Houston); (United States)

DOI:https://doi.org/10.5006/1.3316001· OSTI ID:5857381

Kelly, D J; Robinson, M J ^[1]

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1. Cranfield Univ., Bedfordshire (United Kingdom). School of Industrial and Manufacturing Science

Exfoliation of aluminum-lithium (Al-Li) alloy 8090 (UNS A98091) in plate and sheet form was studied by measuring the compressive forces generated by voluminous grain boundary corrosion products. The forces were shown to be related closely to grain shape, with more elongated microstructures generating higher forces. Aging treatment of the alloy also was a factor. Corrosion product forces were ranked in the order: under-aged > over-aged > peak-aged. High susceptibility of the over-aged temper in 8090 differed from that of conventional, precipitation-hardened Al alloys and was attributed to the formation of anodic phases in the Li containing material. Stress corrosion tests were performed on the plate using double-cantilever beam specimens. The sheet was tested under constant load in the through-thickness direction. K[sub iscc] values, the limiting values of stress intensity for stress corrosion to occur, were compared with the maximum corrosion product forces and supported the proposition that exfoliation proceeded by a stress-assisted corrosion mechanism.

• OSTI ID: 5857381
• Journal Information: Corrosion (Houston); (United States), Journal Name: Corrosion (Houston); (United States) Vol. 49:10; ISSN 0010-9312; ISSN CORRAK
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360105* -- Metals & Alloys-- Corrosion & Erosion
AGING
ALLOYS
ALUMINIUM ALLOYS
CHEMICAL REACTIONS
CORROSION
CRACKING
DECOMPOSITION
GRAIN SIZE
HEAT TREATMENTS
LITHIUM ALLOYS
MICROSTRUCTURE
PYROLYSIS
SIZE
STRESS CORROSION
THERMOCHEMICAL PROCESSES