Desorption-recombination kinetics and mechanism of a mechanically milled nano-structured Nd16Fe76B8 alloy during vacuum annealing

► Nanocrystalline NdFeB-type magnets by desorption-recombination in situ annealing under vacuum. ► The effects of sintering parameters on kinetics and underlying mechanisms were clarified. ► Achieving optimum magnetic properties by annealing at 780 °C for 30 min due to nanocrystallization of Nd2Fe14B phase. ► The kinetics can be well described by the equation f = 1 − exp (−ktn), where k(T) = k0 exp (−Ea/RT). ► The activation energy Ea was figured out to be 224 kJ/mol, and n fell in the range of 0.91-0.97.