Effect of Homogenization Annealing Treatment on Microstructure and Properties of Fe(Al, Ta)/Fe₂Ta(Al) Eutectic Composites by Electron Beam Floating Zone Melting

Fe(Al, Ta)/Fe₂Ta(Al) eutectic composites exhibit promising application prospects in aerospace engine hot-end components and high-temperature corrosion-resistant structural parts of advanced energy systems due to excellent combination of the Fe-based solid solutions with the high-temperature strength of Fe₂Ta(Al) Laves phases during directional solidifcation process. However, coarse grains in unstable growth zones can be observed, which affects the comprehensive properties of the composite. In this paper, homogenization annealing was carried out on the directionally solidified Fe(Al,Ta)/Fe₂Ta(Al) eutectic composites. Microstructure characteristics, mechanical properties, and corrosion resistance of master alloy, directionally solidified Fe(Al,Ta)/Fe₂Ta(Al) eutectic composites and homogenization annealing-treated Fe(Al,Ta)/Fe₂Ta(Al) eutectic composites, were systematically investigated by scanning electron mircroscope (SEM), x-ray diffraction (XRD), tensile testing, friction experiment and electrochemical experiment, respectively. The results show that the coarser reinforced Fe₂Ta(Al) phases in the unstable growth zones are refined and uniformly distributed after being annealed at 1200 °C for 1 h. The fracture model of Fe(Al, Ta)/Fe₂Ta(Al) eutectic composites changes from pure brittle fracture to quasi-cleavage fracture after homogenization annealing. Meanwhile, strength and toughness are also significantly improved. The friction property and corrosion resistance have also been improved. This provides fundamental insights and technical support for solving the room temperature brittleness of Fe-Al intermetallic compounds, which can facilitate and promote the research and development of new high-temperature structural materials.