ARTÍCULO

Effect of Quenching and Normalizing on the Microstructure and Magnetocaloric Effect of a Cu–11Al–9Zn Alloy with 6.5 wt % Ni–2.5 wt % Fe

E. J. Gutiérrez Castañeda , R. E. Barreras Castro, A. Contreras Briseño, B. Fernández Arguijo, A. A. Torres Castillo, A. Salinas Rodríguez, J. T. Elizalde Galindo and S. A. Palomares Sánchez
Magnetochemistry 2019, 5, 48; doi:10.3390/magnetochemistry5030048, 2019.

ABSTRACT:

First-order phase transitions (FOPT) and second-order phase transitions (SOPT) are commonly observed in Cu alloys containing lanthanide elements, due to their electronic configuration, and have an important effect on the optimization of their magnetocaloric effect (MCE). Alloys containing rare earths have the best magnetocaloric response; however, these elements are very expensive, due to their obtaining and processing methods. The present work reports the effect of using 3d transition elements and thermal treatments on the microstructure and MCE of Cu–11Al–9Zn alloys with 6.5 wt % Ni and 2.5 wt % Fe. It was found that thermal treatments of quenching and normalizing, as well as the use of Ni and Fe, have an important influence on both the resulting phases and MCE of the investigated alloy. MCE was calculated indirectly from the change in the magnetic entropy (–DSm) under isothermal conditions, using Maxwell´s relation; it was found that samples subjected to normalizing presented a higher magnetocaloric effect than samples with quenching, which was related to the greater disorder in the alloy, due to the coexistence of beta 1 + betaphases.