Heat-treatment influence on Ni-Fe-Cu-Mo nanocrystalline alloy obtained by mechanical alloying

The 77Ni14Fe5Cu4Mo (wt%) powders have been obtained by dry mechanical alloying of elemental powders in a planetary mill under argon atmosphere for milling durations ranging from 2 to 28 h. The alloy formation is obtained after 12-16 h of milling, as shown by the X-ray diffraction and magnetic studies. The crystallite mean size is 13 +/- A 2 nm after 28 h of milling. An optimal heat-treatment temperature was chosen after the analysis of the DSC signals. and the samples were heated at 350 A degrees C for different durations ranging from 0.5 to 4 h. The heat treatment was continued to enhance the alloy formation and to eliminate the internal stresses induced during the milling process. The evolution of the phases amount during the heat treatment was calculated from the X-ray patterns using the Rietveld procedure.