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a b s t r a c tThe phase transformations and aging of the Cu 72.9 Al 15.0 Mn 10.5 Ag 1.6 alloy were studied in the temperature range from 523 to 723 K using measurement of change in microhardness with variation in quenching temperature and aging time, differential scanning calorimetry (DSC), X-ray diffractometry (XRD), magnetization measurements with temperature and applied field, optical microscopy (MO) and highresolution transmission electron microscopy (HRTEM). The results indicated that the bainitic precipitation is dominant with increase in microhardness and the activation energy value obtained for this process is lower than that reported in the literature due to the occurrence of a diffusion process disturbed by the presence of Ag dissolved in the alloy.

The characteristics of the Cu-18.84 at.%Al-10.28 at.%Mn-1.57 at.%Ag alloy after slow cooling from high temperatures were studied using optical and scanning electron microscopies, microhardness measurements with temperature, differential scanning calorimetry, X-ray diffraction, magnetic moment changes with temperature and applied field. The results indicated the presence of a new transition associated with dissolution of the Ag-rich phase. It was also verified that the content of Al strongly interferes with the magnetization of the Cu-18.84 at.%Al-10.28 at.%Mn-1.57 at.%Ag alloy, since at lower Al concentration the relative fraction of the ferromagnetic L2 1-(Cu 2 AlMn) phase is decreased.