Abstract
The Fe63B23Nd7Y3Nb3Cr1 nanocomposite magnets in the form of sheets have been prepared by copper mold casting technique. The phase evolution, crystal structure, microstructural and magnetic properties have been investigated in the as-cast and annealed states. The as-cast sheets show magnetically soft behaviors which become magnetically hard by thermal annealing. The optimal annealed microstructure was composed of nanosize soft magnetic α-Fe (19–29nm) and hard magnetic Nd2Fe14B (45–55nm) grains. The best hard magnetic properties such as intrinsic coercivity, jHc of 1119kA/m, remanence, Br of 0.44T, magnetic induction to saturation magnetization ratio, Mr/Ms=0.61 and maximum energy product, (BH)max of 55kJ/m3 was obtained after annealing at 680°C for 15min. The annealing treatment above 680°C results in non-ideal phase grains growth, which degrade the magnetic properties.
► Synthesis of Fe63B23Nd7Y3Nb3Cr1 amorphous sheets by copper mold injection casting technique. ► Development of high coercivity nanocomposite permanent magnet based on Fe63B23Nd7Y3Nb3Cr1 alloy. ► Microstructural and magnetic properties are affected by alloy constitution magnetic phases. ► Magnet exhibited promising magnetic properties such as: jHc of 1119kA/m, Br of 0.44T, (BH)max of 55kJ/m3.