The Influence of the Wet-Milling Process on the Properties ofNi3Fe and Supermalloy Magnetic Powders

摘要

Nanocrystalline Ni_3Fe, 79Ni16Fe5Mo and 77Ni14Fe5Cu4Mo (wt %) alloysrnwere obtained by wet -milling in argon atmosphere. As process control agent C_6H_6 was used.rnSeveral milling times have been used ranging from 1 up to 40 h. The progressive formationrnof the Ni_3Fe compound and of the NiFeMo and NiFeCuMo alloys, by mechanical alloying,rnwas evidenced by X-ray diffraction. An annealing at 350℃ for 4 h relaxes the internalrnstresses and enhances the solid-state reaction. A typical particle size of 11-12 nm has beenrnobtained after 20 h of milling. Scanning electron microscopy and X-ray microanalysis studiesrnshow the evolution of the chemical homogeneity of the particles and reveal the morphologyrnof the powders. DSC curves and magnetization measurements show an influence of thernC6H6 on the powder properties. Opposite to the dry milling case, the values of the saturationrnmagnetisation decrease continuously versus milling time for wet milling samples.