The Au diffusion in the Ti3Al compound was investigated at six compositions from 25 to 35 at. pct Al by using the diffusion couples (Ti-X at. pct Al/Ti-X at. pct Al-2 at. pct Au; X = 25, 27, 29, 31, 32, and 35) at 1273 to 1423 K. The diffusion coefficients of Au in Ti3Al (D AuTi3Al) are relatively close to those of Ti. The DAuTi3AlS slightly increase with Al concentration within the same order of magnitude. The activation energies of Au diffusion, QAuTi 3AlS evaluated from the Arrhenius plots were relatively close to those of Ti diffusion, QAuTi3 AlS rather than those of Al diffusion, QAu Ti3AlS; therefore, it was suggested that Au atoms diffuse by the sublattice diffusion mechanism in which Au atoms substitute for Ti sites preferentially in Ti3Al and diffuse by vacancy mechanism on Ti sublattice. The influence of the D019 ordered structure (hcp base) of Ti3Al on diffusion of Au and other elements is discussed by comparing the diffusivities in Ti3Al and α-Ti.
|Number of pages||8|
|Journal||Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science|
|Publication status||Published - 2009 Dec 1|
ASJC Scopus subject areas
- Condensed Matter Physics
- Mechanics of Materials
- Metals and Alloys