The structure and magnetic properties of Nd8Fe84-xCuxTi8 (x=0 similar to 3) alloys prepared by mechanical alloying

The effects of a partial substitution of Cu for Fe on the structure and mag netic properties of mechanically alloyed Nd8Fe84Ti8 alloys were studied in detail. Compared with Cu-free Nd8Fe84Ti8 alloys prepared by mechanical allo ying under the same conditions, the temperature necessary for the formation of the Nd(Fe, Ti)(12) phase decreased from 900 to 750 degrees C with the a ddition of 3 at.% Cu. The addition of Cu negatively influenced the nitrogen ation of the Nd(Fe, Ti)(12) phase. The pretreatment of hydrogenation on the Cu-added alloys at 300 degrees C facilitated the formation of nitrides. Wi th increasing the annealing temperature, the intrinsic coercivity of the ni trides increased until it attained a maximum at 850 degrees C. In the 1 at. % Cu-added alloys annealed at temperatures between 750 and 800 degrees C, t he metastable phase Nd(Fe, Ti)(7) was formed. With increasing the annealing temperature, the Nd(Fe, Ti)(7) phase was gradually transformed into the Nd (Fe, Ti)(12) phase. The intrinsic coercivity of the 1 at.% Cu-added nitride s reached a maximum at 900 degrees C. With increasing Cu content, the magne tic properties of the nitrides degraded. (C) 2000 Elsevier Science S.A. All rights reserved.