The hot-deformed magnets are prepared from melt-spun powders by hot pressing and subsequent hot deformation at different temperature with different strain rates. The optimum magnetic properties of H_(cj)=1157 kA/m B_r=1.465T, (BH)_(max)=426 kJ/m3, have been obtained. In order to clarifying the corelationship between hot deformation and magnetic properties, simulation study of hot-deformation process was performed using a three-dimensional finite element method. The strain at different hot-deformation stages and at different regions of the magnet was calculated. The simulation results revealed the effective strain showed a maximum value at the center region of the magnet. However, the effective strain decreased in the both direction of radial and thickness due to friction between die-wall and magnet. The effective-strain uniformity improved with increasing deformation ratio, and exhibited a saturation behavior at the deformation ratio of 75%. The simulation results are good agreement with the measurements of magnetic properties and XRD.
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