Influence of Milling and Compaction Processes οn Magnetic Properties of FeCo Powder

Magnetic and structural studies were performed on $Fe_{50}Co_{50}$ material. The samples (disk-shaped, diameter: 10 mm, thickness: 2.5 mm) were fabricated by compaction of powder under pressure of 800 MPa for 5 min at temperatures 300-600°C. The powder was obtained by milling of $Fe_{50}Co_{50}$ alloy swarfs in high-energy planetary mill. The milling time varied from 1 h to 40 h. In the course of milling process the mean size of alloy pieces was decreasing from about 0.5 mm to 0.05 mm (scanning electron microscopy), which provided more compact structure after compression. The annealing process during compaction strongly reduces a coercive field of the samples. Parameters of conversion electron Mössbauer spectra are almost the same for all samples, which points to not significant changes of atomic and magnetic order after milling and compacting.