Journal of Dental Research, Vol 60, 883-889, Copyright © 1981 by International & American Associations for Dental Research Online Journals
Determination of the AuCu superlattice formation region in gold-copper-silver ternary system
T. Uzuka, Y. Kanzawa and K. Yasuda
The composition and temperature range of the AuCu-type superlattice
formation in the Au-Cu-Ag ternary system was determined by X-ray powder
diffraction. Four distinguishable phase transformations were detected,
i.e., 1) alpha (disordered FCC phase) leads to AuCu I, 2) alpha leads to
AuCu II, 3) alpha leads to alpha 1 (Cu-rich FCC phase) + alpha 2 (Ag-rich
FCC phase). and 4) alpha leads to AuCu3. The stable temperature range of
the AuCu I-type superlattice was restricted to a lower temperature range by
adding silver to stoichiometric and off-stoichiometric Au-Cu alloys.
Depending on the increase in silver content, the co-existing region of the
AuCu II-type superlattice and the silver-rich alpha 2 phase extended to the
lower temperature and over a wide composition range.
