Hot pressing Nd-Fe-B HDDR powders

Details of the important parameters for hot pressing isotropic Nd/sub 16/Fe/sub 76/B/sub 8/ HDDR powders are presented. Optimum magnetic properties may be achieved over broad ranges of green compaction pressure and hot pressing temperature, time and pressure. Isotropic HDDR powders with lower Nd-contents (i.e. Nd/sub 14/Fe/sub 79/B/sub 7/ and Nd/sub 13/Fe/sub 80.5/B/sub 6.5/) may also be hot pressed to full density to produce magnets with energy products 100 kJ/m and some advantages of hot pressing the lower Nd-content compositions are stated. The cause of the enhanced values of remanence obtained nominally isotropic hot pressed HDDR magnets is probably due to some alignment induced during hot pressing. The ease of hot pressing HDDR powder this process is commercially viable, particularly as the HDDR powder production process has been estimated to be cheaper than that of the MQ powder.