A high strength Al–Li alloy produced by laser powder bed fusion: Densification, microstructure, and mechanical properties

Abstract

High strength 2195 Al–Li alloy samples produced by laser powder bed fusion (LPBF) were obtained in this study. The microstructure and mechanical properties were investigated for both the as-fabricated and T6 heat-treated samples. The as-fabricated sample showed a coarse columnar grain microstructure, heterogeneous element distribution, high density of dislocations, and complex precipitation types. After T6 heat treatment, the dominate strengthening T1 (Al2CuLi) plates precipitated in the matrix, and the dislocation density remained high. The as-fabricated 2195 sample showed a yield strength (YS) of 207.7 ± 1.5 MPa, an ultimate tensile strength (UTS) of 340.7 ± 2.9 MPa, and elongation of 17.2 ± 0.9%. After T6 heat treatment, the YS and UTS were dramatically increased to 521.3 ± 14.4 MPa and 587.0 ± 7.2 MPa, and the elongation was 6.9 ± 0.3%. The LPBF of the high strength Al–Li alloy was successfully confirmed.