Isothermal aging kinetics in the Cu-19 at.%Al alloy

The influence of the disordered (Cu)-alpha phase in the isothermal aging ki netics of the Cu-19 at.%Al alloy was studied using microhardness measuremen ts, optical and scanning electron microscopy and X-ray diffractometry. The results indicate that the beta'-->(alpha+gamma (1)) decomposition reaction rate increases with the increase of the temperature in the range between 15 0 and 500 degreesC and at 600 degreesC the reaction is delayed by the alpha phase precipitation. The value obtained for the activation energy indicate s an interface diffusion controlled reaction. (C) 2001 Elsevier Science B.V . All rights reserved.