抄録
Cast alloys with a range of compositions based on Nd15Fe77B8 with additions of Dy and Zr were produced using the hydrogen decrepitation. disproportionation. recombination (HDDR) technique. Magnetic measurements on HDDR powders indicated that additions of Zr tended not to affect the recombination temperatures at which the material began to develop high coercivity but was clearly observed to extend the temperature range. by up to 60°C, over which high coercivity material could be produced. Microstructural analysis has revealed that the Zr doped samples were less prone to the explosive grain growth exhibited by the Zr free samples at these temperatures. Long term corrosion studies carried out on hot pressed materials using HDDR powders have revealed that small additions of Zr or ZrO2 to the melt are able to substantially increase the resistance to corrosion of the resulting magnets.
