The Effect of Cu-Substitution on the Microstructure and Magnetic Properties of Fe-15%Ni alloy Prepared by Mechanical Alloying

In this study, nanostructured (Fe85Ni15)100-xCux (x = 0, 0.5, 1.5, 3 and 5) powders were synthesized via mechanical alloying process. The obtained phases, microstructure, and magnetic properties of these alloys were studied by X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), and vibration sample magnetometer (VSM). XRD results indicated that after suitable time of milling, Ni and Cu were homogeneously distributed in the Fe matrix and (bcc) α-(Fe(Ni-Cu)) solid solution was obtained. It was found that by increasing Cu content in the alloy, work hardening increased, and thus the size of grains decreased while the internal micro strain increased. Also, morphological observations indicated that the addition of Cu led to formation of finer particles. Also, VSM analysis showed that the addition of Cu into Fe-Ni alloys lowered Ms. On the other hand, the coercivity increased by increasing copper content up to 1.5 at. %.   Keywords: Nano-crystalline alloys; Mechanical alloying; Ball mill; Fe-Ni-Cu alloy; Magnetic properties