Thermodynamics of Titanium Alloys. II. The Titanium-Aluminum System.

Activities of titanium and aluminum were measured at 1780K in the body-centered cubic beta phase of the titanium-aluminum system, from zero to forty atomic percent aluminum, using three Knudsen effusion-time-of-flight mass spectrometer techniques. In the first technique the alloy of interest is placed in an ordinary Knudsen cell and the Al27 and Ti48 peak intensities are monitored as a function of composition from zero to forty atomic percent aluminum. In the second technique, aluminum weight loss experiments are carried out to determine the activity of aluminum as a function of composition from fifteen to forty atomic percent aluminum. In the third technique, the triple Knudsen cell is used to measure the activity of titanium. Author