Abstract:The effects of first annealing and sintering temperature on the microstructures and magnetic properties of Dy2O3 doped Nd-Fe-B magnets were investigated. Results show that the effect of first annealing and sintering temperature on magnetic properties is remarkable, especially on the coercive force Hcj, which is closely related to the content of Dy2O3. When the added content of Dy2O3 is 2%, the first annealing can improve Hcj obviously, whereas the effect of sintering temperature is very unconspicuous. When the added content of Dy2O3 is 5%, Hcj is improved evidently with the increase of sintering temperature; however, the first annealing increases Hcj lightly. This is mainly attributed to the following reasons: on one hand, Dy2O3 is reduced to form Nd2O3 particles affecting sintering and annealing system; on the other hand, sintering temperature impacts the diffusion of Dy atom.