| 摘要 |
A method for the preparation of alloys of the SE2Fe17-xTMxNy type where SE stands for a rare earth metal, including Y or a mixture of these metals, while TM stands for Co, Ni, Cu, Zr, Ga, Hf, Ta, Nb, Ti, Si, A1, V, Mo, Cr, Zn or Sn or a mixture of these metals, x=0 to 10, y=>0 to 5 is described. The preparation involves calciothermal reduction of a finely divided, homogeneous mixture of the alloying components, subsequent diffusion of the components, followed by nitriding and separating the calcium oxide and excess calcium formed. The method is characterized by: a) Preparation of an alloy of the SE2Fe17-xTMx by a1) Adjusting the exothermic reaction of the calciothermal reduction by the oxide content of the reaction mixture, so that TM>TR >/=0.9 TM where TM is the melting temperature of the intermetallic phase, and TR is the reaction temperature, a2) Using a reaction mixture having components, excepting calcium, of an average particle size of </=75 mu m, a3) tempering the reaction product at the end at a temperature at least 0.7 times the melting temperature TM of the desired alloy, but less than the melting temperature TM, b) Subsequently nitriding the alloy obtained with nitrogen or a mixture of nitrogen and hydrogen or NH3.
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