MICROSTRUCTURE AND MECHANICAL PROPERTIES OF AN Al-Li-Cu-Mg-Zr ALLOY CONTAINING MINOR LANTHANUM ADDITIONS
(Deptartment of Materials Science and Engineering; Central South University of Technology; Changsha 410083; China)
Abstract: The effect of the addition of minor amounts of La on the microstructure and mechanical properties of an Al-Li-Cu-Mg-Zr alloy was studied.The results showed that in Al-Li alloys some impurities,such as Fe,Si and Na segregated on the grain boundaries,and the addition of minor amounts of La decreased the segregation of these impurities.In addition,La could give rise to grain refinement,and retard the growth of(?)precipitates.The tensile properties and toughness of the Al-Li alloy containing minor amounts of La were improved compared with the La-free Al-Li alloy.
Key words: microstructure; mechanical properties; Al-Li-Cu-Mg-Zr alloy; lanthanum