Hydrogen embrittlement of aged and retrogressed-reaged Al-Li-Cu-Mg alloys

Journal Article · Tue Apr 01 04:00:00 EST 1997 · Acta Materialia

DOI:https://doi.org/10.1016/S1359-6454(96)00287-X· OSTI ID:474171

Thakur, C; Balasubramaniam, R ^[1]

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1. Indian Inst. of Tech., Kanpur (India). Dept. of Materials and Metallurgical Engineering

The hydrogen embrittlement (HE) of Al-2.30 Li-1.24 Cu-0.80 Mg-0.12 Zr and Al-1.90 Li-1.80 Cu-1 Mg-0.09 Zr alloys in different artificial aging tempers and after retrogression and reaging (RRA) treatments has been investigated by tensile testing hydrogen precharged specimens. The influence of RRA and hydrogen charging on the dislocation structure was studied by TEM. The under-aged temper was the most susceptible while the peak-aged temper was the most resistant to HE. The RRA treatment improved the HE resistance of all the tempers. This has been attributed to the reduction in dislocation density upon retrogression and reaging. The alloy with the lower Li content exhibited improved HE resistance. Flat fractographic features near the surface of the hydrogen charged specimen have been correlated to the depth of hydrogen penetration. The formation of LiAlH{sub 4} and LiH in hydrogen charged Al-Li alloys has been confirmed by X-ray diffraction studies. The hydrogen-dislocation interaction and hydride cracking mechanisms of HE have been addressed.

• Sponsoring Organization: Government of India, New Delhi (India)
• OSTI ID: 474171
• Journal Information: Acta Materialia, Journal Name: Acta Materialia Journal Issue: 4 Vol. 45; ISSN 1359-6454; ISSN ACMAFD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
AEROSPACE INDUSTRY
AGING
ALUMINIUM BASE ALLOYS
COPPER ALLOYS
DISLOCATIONS
FRACTOGRAPHY
HEAT TREATMENTS
HYDROGEN EMBRITTLEMENT
LITHIUM ALLOYS
MAGNESIUM ALLOYS
PRECIPITATION
ZIRCONIUM ADDITIONS