For nanophase (Nd, Pr) FeB/α2Fe composite alloys were prepared by melt spinning, the appreciable addition of Zr reduces their average grain size. Observed by atomforce microscopy (AFM), the average grain diameter of crystallized ribbons on their free surface, reduces from 175 nmof Zr2free alloy to 79 nmof Zr21at%, by about 55%. If the concentra-tion exceeds 1%, the effects of Zr on fining grain size are evidently weakened. The average grain size on free surface of Zr2115at% is 72 nm. With the addition of 1at% Zn, the bonded magnets has the best combination of properties: Br =01675 T, Hci=616kA•m-1, (BH) max=77 kJ•m-3. Below 1at%, the coarser grains lead to a lower magnetic property. Beyond 1at%, the layer of Zr-rich intergranular phase will thicken, which results in weakening of the exchange coupling among adjacent grains, and then causes degrading of magnetic properties of magnets.

The optimum quenching rates and annealing conditions to prepare near stoichiometrical (Nd,Pr)12 (FeCoZr) 82B6 bonded magnets were investigated by using sub-overquenching and post annealing method. The quenching rates, annealing temperatures, and annealing time directly influence the microstructure and magnetic properties of alloy ribbons. The opti-mum magnetic properties of bonded magnets are achieved by melt spinning at 24ms-1wheel surface speed, annealing at 655℃ for 10 min, and bonding with 3.25% (mass fraction) epoxy. The best magnetic properties of remanence Br, in-trinsic coercivity Hci and maximum energy product (BH) max are 0. 669 T, 811 kA•m-1, and 75kJ •m-3, respectively.

在粘结NdFeB磁体模压成形过程中存在较大的压力损失，引起磁体密度分布不均匀，致使磁体密度减小。本文研究了压制压强、预压成形和压制方式等对粘结NdFeB磁体结构和磁性能的影响及机理。研究表明：随着压制压强提高，粘结NdFeB磁体的密度和磁性能显著增大；粒度配合、预压成形和双向压制等办法均可增大粘结NdFeB磁体的密度和磁性能；在适当的压制压强下，将粒度配合、预压成形及双向压制工艺结合，制备出密度达到6.5g/cm3、磁能积达到104kJ/m3的粘结NdFeB磁体。

为了系统研究合金元素对Nd-Fe-Co-Zr-B系永磁合金磁性能的影响，采用均匀设计方法设计了Nd、Co、Zr和B的4因素6水平U18（64）试验方案，根据试验结果，建立了合金成分与磁性能之间的人工神经网络（ANN）预测模型。利用该预测模型获得的成分2性能的二维曲线、三维曲面及等高线图，研究了单个合金元素以及多元素间的交互作用对NdFeB磁体磁性能的影响规律。结果表明：预测结果与实测结果吻合良好，预测精度高；Nd、Zr为提高矫顽力Hcj而降低剩磁Br的元素；Co、B则对提高Br有利而对提高Hcj不利；合金元素对Hcj与Br的影响呈相反的趋势；元素间交互作用对磁性能影响显著。

采用工艺参数范围较宽的部分过快淬加晶化退火工艺，制备了快淬（Nd0.8Pr0.2）x（FeCoZr）94-xB6（x=1210，10.5，1010，9.0）粘结磁体，研究了稀土含量对磁体磁性能的影响规律。部分过快淬获得的由非晶和微晶共同组成的条屑，在实验优化的退火条件下晶化处理后，可获得最佳磁性能。稀土含量直接决定磁体的磁性能，随稀土含量的减少，磁体的剩磁Br增加，而内禀矫顽力Hci和最大磁能积（BH）m下降，10%是磁体磁性能发生较大变化的临界稀土含量。低于这一含量，合金中软磁相体积分数超出软磁相被完全耦合的临界值，Br增加缓慢，Hci和（BH）m迅速下降。这一实验结果与本文提出的完全耦合软磁相体积分数示意模型的计算结果相一致。