Sintering and heat treatment of Al_(15)Ti5Co_(35)Ni_(25)Fe_(20) high-entropy alloy

摘要

The new Al_(15)Ti5Co_(35)Ni_(25)Fe_(20) high entropy alloy was obtained by the powder metallurgy from the elemental powders (-325 mesh). The obtained alloy should be characterized by the dual BCC + FCC phase microstructure according to the valence electron concentration calculations (VEC=7.9). The main aim of the research was to determine the optimal conditions for sintering and heat treatment of Al_(15)Ti5Co_(35)Ni_(25)Fe_(20) high entropy alloy. The alloy was sintered for 40 minutes at 600 °C for the preliminary consolidation of the powders and initial diffusion of the material. Then samples were annealed at various temperatures: 700, 800, 900, 1000 °C for 1 hour. Samples after annealing were characterized by the XRD and SEM. For the chosen temperature the annealing time was elongated to 2, 3, 5, 10 and 20 hours. The chemical homogeneity was determined.