Characterization of Nb-8 wt.% Al wires by analytical electron microscopy

Analytical electron microscopic observations of longitudinal cross-sections of Nb-8 wt.% Al powder metallurgy processed wire are presented. Grains were found of unreacted Nb, Nb-Al which was identified as Al5 Nb-Al by convergent beam electron diffraction (CBED), and Nb-Al grains identified as Nb2Al by CBED. No unreacted Al is found. High resolution TEM views for each phase and for regions at the phase boundaries are also presented. Comparisons of the composition of arc melted Nb3Al are made with the low temperature P/M processed Al5 phase.