Thermomagnetic study of the high-temperature oxidation behavior of Nd-Fe-B permanent magnets and powders

Oxidation kinetics changed at temperatures below 400 degrees Celsius for permanent and powdered Nd-Fe-B magnets in an experiment to measure oxidation under heat treatment at 360-600 degrees Celsius and a pressure of 1 Pa. The magnets were studied under states equivalent to that of thermally annealing sintered magnets. The compositions of four types of sintered magnets was compared after thermal annealing, to obtain coefficients for temperature dependence and specific magnetization.