LASER-SURFACE HEATING OF ND-FE-B, ND-FE-CO-B, AND BAO-6FE2O3 PERMANENT-MAGNETS

Hot-pressed Nd-Fe-B, epoxy-bonded Nd-Fe-Co-B, and BaO-6Fe2O3 (ferrite) permanent magnets are heated by scanning their surfaces with an argon ion laser beam. The laser heating response of each magnet material is examined by measuring the depth of the heat-affected zone as a functi on of beam power and scan rate. An analytic heat transfer model is use d to provide a convenient description of the laser surface heating pro cess. The temperature distribution in the magnets is calculated to est imate the depth of the heat-affected zone as defined by the position o f the Curie temperature isotherm. Agreement is good among the calculat ed and measured depths for all three permanent magnet materials.