Abstract：The effects of melt-spinning speed and micro-doping of Nb, a high-melting-point element, on the mag‐
netic properties and microstructure of Nd26Pr3FebalCo4Ga0.42B0.92Nb（x x=0，0.5）melt-spun ribbons were investigated.
Increasing the melt-spinning speed and doping Nb can significantly refine the grains, which increases the amor‐
phous content of the melt-spun ribbons, resulting in a rapid decrease in the magnetic properties of the ribbons. The
increase in the amorphous content leads to an increase in the crystallization temperature and optimum heat-treat‐
ment temperature of the ribbons. After the optimum heat treatment, the properties of the ribbons are improved,
among which the ribbons with a melt-spinning speed of 30 m/s and the doped with 0.5% Nb obtains a good mag‐
netic performance due to a low degree of grain growth and a high coupling effect between phases. A uniform
microstructure is observed by SEM and XRD. The best magnetic properties are obtained at melt-spinning speed is
30 m/s, Br=0.91 T，μ0Hcj=1.82 T，（BH）max=141.65 kJ/m3. The ribbons doped 0.5% Nb have the highest coercivity at
the slight reduction of remanence, Br=0.88 T，μ0Hcj=2.19 T，（BH）max=140.10 kJ/m3.
2023, Vol. 33 
