The magnetized sintered NdFeB (MS-NdFeB) permanent magnet material is difficult to machine due to high hardness, brittleness, and magnetic force. In this paper, the electrical discharge machining (EDM) of the MS-NdFeB workpiece is studied to improve the machining process of the MS-NdFeB. In addition to the material removal rate (MRR) and the surface roughness (SR), the change rate of the magnetic flux density (MCR) for the MS-NdFeB is proposed and used as the research index of their machining effect by the EDM process. By orthogonal experiments, using the intuitive analysis method and the analysis of variance (ANOVA) method, study the influences of the peak current, the pulse on time, the pulse off time, and the magnetic field intensity of the processing area (MF) on the MRR, the SR, and the MCR. The scanning electron microscope (SEM) pictures of the machined MS-NdFeB surfaces are obtained based on the experimental design with a one-factor variation. The comparative experiment is performed to reveal the change of the MCR in EDM. The intuitive analysis of the orthogonal experimental result reveals regularities of influences. The ANOVA reveals the significance of influences. The regularities and significance of influences of machining parameters on the machining effects are analyzed assisted by the analysis on these SEM pictures and the comparative experimental results. The optimal combinations of machining parameters for MRR, SR, and MCR are obtained by single-objective optimization. The verification experiments prove the reliability of the single objective optimization results.

磁化烧结钕铁硼（MS-NdFeB）永磁材料硬度高、脆性大、磁力强，加工难度大。本文研究了MS-NdFeB工件的电火花加工（EDM），以改进MS-NdFeB的加工工艺。除了材料去除率 (MRR) 和表面粗糙度 (SR) 外，还提出了 MS-NdFeB 的磁通密度 (MCR) 变化率，并将其用作其电火花加工加工效果的研究指标. 通过正交实验，采用直观分析法和方差分析（ANOVA）方法，研究峰值电流、脉冲导通时间、脉冲关断时间、加工区磁场强度（MF）对MRR、SR 和 MCR。机加工的 MS-NdFeB 表面的扫描电子显微镜 (SEM) 图片是基于具有单因素变化的实验设计获得的。进行对比实验以揭示 EDM 中 MCR 的变化。对正交实验结果的直观分析揭示了影响的规律性。方差分析揭示了影响的重要性。通过对这些SEM照片的分析和对比实验结果，分析了加工参数对加工效果影响的规律和意义。MRR、SR 和 MCR 加工参数的最佳组合是通过单目标优化获得的。验证实验证明了单目标优化结果的可靠性。