N. Boukos et al., Transmission electron microscopy and X-ray diffraction study of T-1 and Omega precipitates in Al-Li alloys, PHIL MAG A, 80(5), 2000, pp. 1055-1063
Two Al-Li-Cu-Mg based alloys were studied by means of transmission electron
microscopy and X-ray diffraction. Apart from the well known precipitation
of delta', beta', S' and T-1 phases in both alloys, coprecipitation of the
Omega phase was observed in the low Li, high Cu:Mg,Ag containing alloy. Sim
ulation and experimental electron nanodiffraction and X-ray diffraction tec
hniques were used in order to differentiate the T-1 From the Omega phase. T
he Omega precipitates seem to nucleate preferentially on subgrain boundarie
s, possibly due to the higher dislocation density at the boundaries compare
d with that of the matrix inside the grains.