en Research Paper Research Paper Ni and Cu elemental powder mixtures containing 25, 50, and 75% at Cu were subjected to mechanical alloying in a planetary ball mill under various milling times. Structural evolution was analyzed by means of X-ray diffraction and scanning electron microscopy. Experimental results indicated that nanostructured solid solution alloy powders having homogeneous distribution of Ni and Cu were formed by milling-induced interdiffusion of the elements. Average crystallite size of the as-milled powders was decreased with increasing Ni content and milling duration, and found to be in the order of 15-40 nm after 30 h of milling for all powder compositions. Moreover, lattice parameter and lattice strain of solid solutions were increased with the time of MA, which was more intense for nickel-rich alloys Ni-Cu binary alloys, Mechanical alloying, High-energy ball milling, Nanostructured alloys 27 31 http://ijmse.iust.ac.ir/browse.php?a_code=A-10-127-21&slc_lang=en&sid=1 A. Karimbeigi 180031947532846002156 180031947532846002156 No A. Zakeri zakeria@iust.ac.ir 180031947532846002157 180031947532846002157 Yes A. Sadighzadeh 180031947532846002158 180031947532846002158 No