Microstructure and micro-area composition of Zirlo alloy and M5 alloy

The microstructure and micro-area composition of Zirlo alloy and M5 alloy were analyzed by high-resolution transmission electron microscope and energy dispersive spectrometer. The results show that the spherical second phase in M5 alloy was dispersed on the grain boundary and in the grain, and the size was about 50 nm. The main components of the second phase were Zr element and Nb element, and the second phase was β-Nb phase with body-centered cubic structure. Two kinds of second phase particles with different sizes were dispersed in Zirlo alloy. One was β-Nb with body-centered cubic structure, and the size was 20－40 nm. The other was Fe₂Nb_0.4Zr_0.6 phase with a close-packed hexagonal structure, with a size of about 100 nm.