On the Partial Atomic Volume of Aluminium in the Titanium-rich Phases of the Binary System Ti-Al

The dependence of the unit cell parameters upon the mole fraction of aluminium as well as that upon temperature and also the macroscopic density were investigated in the homogeneity range (0.25 0.25, titanium is substituted by aluminium without structural-vacancy formation. The axial ratio c/a changes neither with temperature nor with mole fraction. The average atomic volume deviates strongly from the additivity of the pure elements titanium and aluminium. The partial atomic volume of aluminium in the titanium-rich phases belonging to the magnesium^ family shows a significant small value, VM/T 14.75 A3, and indicates (i) an effective charge transfer and (ii) the strong bonding between aluminium and titanium atoms in this advanced engineering intermetallic. © 2000 Carl Hanser Verlag. All rights reserved.