New cubic precipitate in Al–3.5Cu–1.0Li–0.5In (wt.%) alloy

Abstract The precipitations of Al–3.5Cu–0.7Li alloy aging at 175 °C were studied by HREM and 3DAP. A new cubic phase precipitate has been discovered as the dominant phase, which is assumed having a cubic structure with a ≈ 0.83 nm and the orientation relationship with the matrix is: (001)p//(001)α, [010]p//[010]α. Considering the good match of observed and simulated HREM images, we suggest that the studied cubic phase is a variant of Al5Cu6Mg2 with Li substituting the Mg positions.