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 Nb 2 Al 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 Nb 3 Al are made with the low temperature P/M processed Al5 phase.