Micromachining of magnetic materials

The results of an investigation of laser-cutting and EDM of NdFeB and MnZn ferrite are presented. Using a sub-microsecond-pulsed Nd:YAG laser (lambda = 1.06 mu m) at a repetition rate of 1 kHz and pulse energy of 1.8 mJ, the 0.5 mm thick ceramic NdFeB and ferrite plates were cut at a approximate spe ed of 1 mm/s in 6-8 passes. The cut width was in the range of 65 to 80 mu m in the case of NdFeB, and 30 to 50 mu m for ferrite. Cutting in water prov ided best cut quality and elimination of the debris compared to cutting in air. The cutting of the ferrite by pulsed laser beam was found to lead to c racking of the material and is not recommended. Wire EDM gave good results both for cutting of NdFeB and ferrite despite of relatively high resistivit y of the latter. Average surface roughness of cuts was 0.5 mu m. (C) 1999 E lsevier Science S.A. All rights reserved.