Thermal behavior of α-(Cu–Al–Ag) alloys, i.e. alloys
with composition less than about 8.5 mass% Al, was studied using differential
scanning calorimetry (DSC), differential thermal analysis (DTA), scanning
electron microscopy (SEM), energy dispersive X-ray analysis (EDX) and X-ray
diffractometry (XRD). The results indicated that the presence of silver introduces
new thermal events ascribed to the formation of a silver-rich phase and, after
addition higher amounts than 8 mass% Ag to the Cu–8 mass% Al alloy it
is possible to observe the formation of the γ1
phase (Al4Cu9), which is only
observed in alloys containing minimum of 9 mass% Al. These results may be
attributed to some Ag characteristics and its interaction with Cu and Al.
Authors:A. G. Magdalena, A. T. Adorno, T. M. Carvalho, and R. A. G. Silva
. This effect is associated with Ag–Alinteraction during Al atoms diffusion and the formation of γ 1 phase.
The Cu-rich phase of the Cu–Al–Ag alloys is a fcc solid solution of Al and Ag in copper and the high temperature β phase has a bcc
Authors:R. A. G. Silva, E. S. Machado, A. T. Adorno, A. G. Magdalena, and T. M. Carvalho
heating and that these precipitates dissolve preferentially in the (α + γ 1 ) phase [ 8 ], due to Al excess in this phase and to the Ag–Alinteraction. Hence, this peak can be related with Ag precipitates dissolution in the (α + γ 1 ) phase, formed from