The effect of the desorption-recombination temperature on the microstructure and magnetic properties of hydrogenationdisproportionation-desorption-recombination (HDDR) processed Nd-Fe-B powders was studied. The Nd x B 6.4 Ga 0.3 Nb 0.2 Fe bal (x=12.5-13.5, at.%) casting alloys were pulverized after homogenizing annealing, and then subjected to HDDR treatment. During the HDDR process, desorption-recombination (DR) reaction was induced at two different temperature, 810 • C and 820 • C. The higher Nd content resulted in enhanced coercivity of the HDDR powder, and which was attributed to the thicker and more uniform Nd-rich phase along grain boundaries. But this uniform Nd-rich phase induced faster grain growth. The remanence of the powder DR-treated at 820 • C is higher than that DR-treated at 810 • C. In addition, it was also confirmed that higher DR temperature is much more effective to improve squareness.

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