FABRICATION OF NANOSTRUCTURED Ni-C SOLD SOLUTION ALLOYS BYMECHANICAL ALLOYTNG

Cu and Ni elemental powder mixtures containing 25, 50, and 75 at% Cu. were subjected to mechanical alloying (MA) in a planetary ball mill under various milling times. The structural evolution during mechanical alloying was characterized by means of X-ray diffractometry (XRD) and scanning electron microscopy (SEM). Experimental results indicate that nano-structured solid solution with single-phase and homogeneous distribution of Ni and Cu has been prepared through interdiffusion mechanism. Average crystallite size of as-milled powders was decreased with increasing Ni content and increasing milling time, and found to be in the order of 15-40 nm after 30 h of milling for all powder compositions. Moreover, lattice constant and lattice strain of solid solutions were increased during mechanical alloying.