Published online by Cambridge University Press: 01 January 1992
Microstructural observations, phase identification, and hardness measurements of several ternary and quaternary A13Nb− and A13Ti-based alloys containing Ni or Fe have been carried out after homogenization at 1100°C. An L12 phase is formed in an (A1,Fe)3Ti-based alloy when a small amount of Nb is added. Conversely, in Al-Nb-Ni alloys whose compositions are based on Al3Nb, no L12 phase has been detected. In this case, alloys are either three-phase(B2, DO22 and Laves) or two-phase(B2 and Laves). The absence of the Ll2 phase formation in AlgNb-based alloys containing Ni is attributed to limited solubility of Ni in the Al3Nb compound. Rapidly solidified and slowly cooled specimens have also been analyzed.