Formation and chemical leaching of non-equilibrium Al0.6(Fe75Ni25)0.4 alloy powders by rod milling

This is a report on the formation and chemical leaching of metastable non-equilibrium Al0.6(Fe75Ni25)0.4 alloy powders by rod milling. An X-ray diffractometer, scanning electron microscopy, a transmission electron microscope, a differential scanning calorimeter, and a vibrating sample magnetometer were utilized to characterize the rod-milled and leached specimens. The crystallite size, calculated using Williamson–Hall and Scherrer methods, decreased with milling time, while the internal strain increases for milling time, less than 400 h. The as-milled alloy powders retained their bcc structure after being treated at room temperature to remove the Al with a 30-wt% KOH solution. The leached L1 specimen was transformed into a fcc phase and a NiFe2O4 after annealing at 600 °C for 1 h. The saturation magnetization decreased with milling time and reached values of 8.05 emu/g after 400 h of milling. But, on cooling of the leached specimen from 750 °C, the spontaneous magnetization sharply increased at about 577.1 °C.