Synthesis and magnetic properties of Nb-doped Al-Ni-Co-Ti-Cu-Fe permanent magnets

摘要

Magnetic and microstructural properties of Nb-doped Al-Ni-Co-Cu-Ti-Fe permanent magnets were studied in terms of various processing conditions and niobium concentration. Optimization in magnetic properties can be obtained by controlling microstructures and adopting proper processing thermal cycle temperature, holding time, cooling rate, and magnetic field strength. Niobium addition up to 1.0 wt% leads to the refinement of the microstructure, promotes shape anisotropy, and improves magnetic properties. The best magnetic properties in 8.33Al-15.33Ni-34.67Co-3.9Cu-5.4Ti-1.0Nb-Fe magnets are obtained as coercive force (H_c) of 1.53 kOe (121.80 kA/m), remanence (B_r) of 7.98 kG (0.79 T), saturation magnetization (B_s) of 19.0 G (1.90T), and magnetic energy ((BH)_(max)) of 4.35 MGOe (34.62 kJm~3). These magnets are attractive for future applications due to their good magnetic properties, better machine-ability, and economical processing.