Nature of Formation of the Areas Having an Ultrafine Grain Structure in Al-Li-Mg System Alloys


Article Preview

The structure of Al-Li-Mg system alloy 1420, containing a small quantity of Sc, Zr, Ti was investigated in cast, homogenized, hot-pressed, quenched and aged conditions, using the methods of optical metallography, transmission electron microscopy and X-ray examination. An existence of areas, having fine grains (20-30 nm)- "Ultrafine Grain areas"(UFGA) was observed in all the investigated conditions. UFGA are located on the boundaries, sub boundaries and S1(Al2MgLi) phase particles. UFGA can also form near the particles of crystallization origin. These areas have a complex phase composition. Inside the UFGA the particles of S1(Al2MgLi) phase and also δnon-phase, investigated in [1] are always present whereas δ'(Al3Li) precipitations are absent. These areas are formed during crystallization and hot deformation. Their composition changes during the treatment. The nature of these changes is considered.



Materials Science Forum (Volumes 519-521)

Edited by:

W.J. Poole, M.A. Wells and D.J. Lloyd




A.A. Alekseev et al., "Nature of Formation of the Areas Having an Ultrafine Grain Structure in Al-Li-Mg System Alloys", Materials Science Forum, Vols. 519-521, pp. 265-270, 2006

Online since:

July 2006




[1] Alekseev A.A., Lukina E.A., Ermolova M.I., Khokhlatova Mechanism of δ'-phase formation in Al-Li and Al-Li-Mg systems alloys; Materials Science Forum Vols. 396-402 (2002) pp.989-994.


[2] Khokhlatova L.B., Ber L.B., Alekseev A.A., Kolobnev N.I., Ukolova O.G., Lukina E.A. Phase transformation during long-term low temperature exposure of 1424 Al-Li-Mg alloy; Materials Science Forum Vols. 396-402 (2002) pp.1395-1398.


[3] Prasad K.S., Gokhale A.A., Banerjce D., Goel D.B. New nanocrystalline regions in 1420 AlLi alloy; Scripta Metallurgica et Materialia, v. 26, June 15, 1992, pp.1803-1808.


[4] Livanov V.A., Bukhanova A.A., Kolachev B.A. «Struggle with hydrogen embitterment, Aviation Industry», 1957, №7, p.55.

[5] Fridlyander I.N., Chuistov K.V., Berezina A.L. Aluminium-lithium alloys, structure and properties; Kiev, Naukova Dumka (1992).

[6] Elagin V.I., Zakharov V.V., Pavlenko S.G., Rostova T.D. Influence of zraddition on aging of Al-Sc alloy; FММ, 1985, v. 60, issue 1.

[7] Gayle F.W., Levoy N.F., Vander Sande J.B. Transition element modification of Al-Li. J. Metall, 1987, №5, р. 33-35.

[8] Hirsh P.B., Hampfri F.J. Strength and ductility physics /Moscow, «Metallurgy», 1972, p.158.

[9] Setyukov O.A., Krivko A.N., Ruchyova N.V. Effect of heat-treatment conditions on stress relaxation and aging kinetics in Al-Mg-Li alloys, Nonferrous metals, 1994, №4, pp.54-56.