A new statistical method for atom location by channelling-enhanced microanalysis is applied to γ- α2 duplex Ti-Al based alloys containing ternary element additions of V, Cr, Mn, Ga, Y, Zr, Nb, Mo, La, Hf, Ta and W at the 1 at.% level. Incoherent channelling patterns, formed by the variation in characteristic X-ray emission as a function or orientation, are collected from a number of different zone axes from both phases. Comparisons of experimental patterns with calculated maps for various crystallographic sites indicate that the ternary atoms are incorporated substitutionally in the atomic structure of both the γ and the α2-phases and do not occupy interstitial sites. The crystallographic site distribution of the ternary elements is determined through X2-minimization techniques, together with quantitative error limits. The structure of the nonstoichiometric α2-phase is investigated by convergent-beam electron diffraction.
|Number of pages||26|
|Journal||Philosophical Magazine A: Physics of Condensed Matter, Structure, Defects and Mechanical Properties|
|Publication status||Published - 1 Jan 1996|