Recycling Rare Earth Permanent Magnets

The aim of this study is to investigate the effect of different process parameters on densification of Samarium Cobalt 1:5 series (SmCo 5) magnet by powder metallurgy technique. Different parameters for sintering and heat treatment process such as particle size, load of press, sintering time and temperature, furnace atmosphere and heating rate were tested in order to achieve the highest density. To analyze and evaluate the microstructure and particle size of manufactured magnets scanning electron microscopy (SEM) and X-ray diffraction (XRD) tests were conducted. Results of different tests showed that sintering temperature as well as furnace atmosphere is among the most important parameters affecting on final density of the samples. Investigations illustrated that highest density could be obtained with the sintering of green bodies which made from initial particles with the size of 3 to 6 µm in vacuum condition at 1135˚C for 30 min by rapid heating at the shortest time. KEYWORDS Samarium Cobalt, rare earth permanent magnet, powder metallurgy, heat treatment.