Hey

I want to investigate demagnetization in a surface-mounted PMSM. I try to replicate the work from an earlier colleague of mine where he used an electric discharge machine (EDM) for demagnetizing a rotor. I believe the principle is that the magnets become weakened by passing a current through them. I tried on a broken rotor (bent shaft) for testing the equipment. Sure thing the magnet got less strength afterward, but the surface gets corroded. The magnet on the right in the attached picture. Have any other tried to demagnetize (partially) a rotor with an EDM or other method involving passing DC or AC through the magnets on one of the poles?

Best regards

Sveinung