The effect of the hot-compaction temperature on the microstructure and magnetic properties of anisotropic
nanocrystalline magnets was investigated. The hot-compaction temperature was found to impact both the magnetic properties and the microstructure of die-upset magnets. The remanence of the isotropic precursor
increases slightly with the improved hot-compaction temperature, and the grains start to grow on the flake
boundary at higher hot-compaction temperatures. After hot deformation, it was found that the change in the
magnetic properties was the inverse of that observed with the hot-compaction temperature. Microstructural
investigation showed that die-upset magnets inherit the microstructural characteristics of their precursor. For
the die-upset magnets, hot pressed at low temperature, scarcely any abnormal grain growth on the flake
boundary can be seen. For those hot pressed at higher temperatures, however, layers with large equiaxed
grains could be observed, which accounted for the poor alignment during the hot deformation, and thus the
poor magnetic properties.