Hydrogen effects on the mechanical properties of Al-Li 2090 alloy in an acid environment

Journal Article · Tue Jan 06 04:00:00 EST 1998 · Scripta Materialia

DOI:https://doi.org/10.1016/S1359-6462(97)00480-6· OSTI ID:603871

Velez, E; Sundaram, P A ^[1]

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1. Univ. of Puerto Rico, Mayaguez (Puerto Rico). Dept. of Mechanical Engineering

Although aluminum-lithium alloys are attractive materials for aeronautic and aerospace applications because of their lower density and higher elastic modulus compared to conventional aluminum alloys, their bane is their poor ductility and susceptibility to environment induced cracking (EIC). EIC of Al-Li alloys has been fairly well researched and the role of hydrogen in causing this phenomenon has been proposed. Of the various mechanisms proposed to explain the phenomenon of hydrogen embrittlement (HE) in Al-Li alloys, the formation of brittle hydrides, LiH and LiAlH{sub 4} has been indicated as the cause of embrittlement. This mechanism has been accepted widely, both for precharged specimens and in stress-corrosion cracking. Literature is not consistent with regard to the phenomenon of HE in Al-Li alloys, believed to be due to the widely varying experimental conditions used by each group of investigators. There is also no general agreement on the effect of aging temper on HE in these alloys. Some investigators note that the HE resistance is poor for the overaged (OA) condition while others claim the underaged (UA) temper as having poor resistance to HE. Some others have also reported that the peak aged (PA) temper is most resistant to HE. Most studies of HE for the Al-Li alloy system has been carried out in a NaOH environment. The main objective of this study is to obtain an understanding of the effect of hydrogen on the mechanical properties of a 2090 commercial alloy using electrolytic charging conditions in an acid environment for different tempers.

• OSTI ID: 603871
• Journal Information: Scripta Materialia, Journal Name: Scripta Materialia Journal Issue: 3 Vol. 38; ISSN 1359-6462; ISSN SCMAF7
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
36 MATERIALS SCIENCE
AEROSPACE INDUSTRY
AGING
ALUMINIUM BASE ALLOYS
HYDROGEN EMBRITTLEMENT
LITHIUM ALLOYS
MECHANICAL PROPERTIES