Structural and Phase Characteristics of the Ni 3 Al-Based Intermetallic Alloy Fabricated by High-Gradient Directional Solidification and Selective Laser Melting

The microstructure and the phase composition of an experimental Ni 3 Al-based intermetallic alloy containing (wt %) 7.8 Al, 14.5 Ta, 0.9 Mo, 0.5 W, 0.5 Re, 0.15 C, and Ni for balance, which was prepared by slow (6 mm/h) high-gradient (15°C/mm) directional solidification and selective laser melting, are studied, and the lattice parameters of phases and solidus and liquidus temperatures are determined. The phase compositions of the intermetallic alloy samples prepared by these technologies are found to be identical and consist of a γ'-phase matrix and TaC carbide particles.