The phase transformation and microstructures of B-doped Ni-23at%Al-11.84at%Fe alloy were studied by transmission electron microscopy and X-ray diffraction. The alloy consists of ordered L12 phase (γ′), ordered B2 phase (β) and disordered face-centered cubic phase (γ). Disordered γ phase deposited preferentially at the antiphase domain boundaries. There was no difference in crystal orientations of γ phase and γ′ phase, but γ phase contains slightly higher iron. Tiny particles of γ′ phase also precipitated from γ phase during slow cooling to room temperature. The orientation relationship between β phase and γ′ phase and the crystal structure of NiAl martensite formed during quenching were determined. The substructures of the martensite were analyzed. Further ordering could occur during quenching.

Phase Transformation and Microstructures of B-doped Ni3Al with Iron Additions. Kong, X., Jin, T.: Rare Metals, 1991, 10[2], 86-92