LASER CUTTING OF RARE-EARTH NdFeB PERMANENT MAGNETS

The possibility of laser cutting of rare-earth NdFeB permanent magnets is studied. An industrial Navigator KS-5VDM1-3 laser complex (VNITER, Russia) is used. Blanks of sintered permanent magnets intended for cutting were 10, 4.5, 3, and 2 mm thick. The cutting was performed in air. The used cutting conditions ensure the cutting of a blank for one pass. The cutting rate was varied in wide range. The magnetic properties of studied blanks were determined via measuring the magnetization reversal curves recorded before and after cutting. Changes in the alloy structure during laser cutting were estimated by X-ray diffraction analysis. The decrease in the magnetic properties during laser cutting was found to depend on the blank thickness. The thinner the magnet blank, the lower the decrease in its magnetic properties. The causes for the decrease in the magnetic properties of NdFeB permanent magnet blanks during laser cutting are local changing the phase composition of alloy and decrease in the degree of texture of blanks. The losses of magnetic properties can be minimized by optimization of laser cutting conditions.