The alloy examined had a composition of Ti-22.8Nb- 1.lAl in at. % or Ti-35Nb-5A1 in wt.%; hereafter it will be referred to as Ti-23-1 1. The specimens, which contained 1580 wt ppm oxygen, originated from bar stock which was extruded at 1038°C, using a 22:1 extrusion ratio. All heat treatments were performed by encapsulating the specimens in quartz under a partial pressure of high purity argon with tantalum foil being wrapped around the specimens to getter any residual oxygen. Transmission electron microscopy (TEM) examinations were performed on foils thinned by ion milling using a gun angle of 150 for 10 hours, followed by 2 hours of milling at 5'.Ion milling was performed using a voltage of 3.5 kV and a current of ImA.