Determination of omega phase morphology in Ti-35% Nb by transmission electron microscopy

Abstract

Considerable x-ray diffraction analysis of omega phase in titanium alloys has been reported; however, little direct observation of its occurrence via electron microscopy has been published. In this work we have demonstrated by means of transmission electron microscopy that the omega phase in titanium-35% niobium precipitates as ellipsoids. By means of dark-field and selected area diffraction microscopy, stereographic projections could be constructed which indicate that the major axes of the ellipsoids (the [0001] crystallographic direction) are parallel to [111] directions in the matrix.