Microstructure Changes in Sn- or Gd-Modified Cu-11%Al-10%Mn Alloy

The effects of the addition of Sn or Gd on the phase transitions of the Cu-11%Al-10%Mn alloy were studied to identify and characterize the phases formed at each transition observed in the differential scanning calorimetry curves. The characterization was carried out by X-ray diffraction, microhardness tests, and magnetization measurements as a function of the applied field. The microstructure was investigated by optical microscopy and scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy. The results showed that the addition of Sn stabilizes the beta phases, and changes the phases present in the Cu-11%Al-10%Mn alloy, whereas the addition of Gd does not interfere with the phase transitions. In addition, Sn improves the alloy saturation magnetization, while addition of Gd deteriorates it.