The evolution of substructure in 50%Ni+50%Nb powder mixture during ball milling

The conventional X-ray line profile analysis has been employed to study the kinetics of substructure evolution in Ni and Nb during high energy ball milling of both the elemental powders and their equiatomic mixture. Such substructure parameters of the formed nanocrystalline structure as crystallite size (column length), crystallite size distribution, root mean square strain and dislocation density have been measured. While crystallites equal to 12 nm (Ni) and 9 nm (Nb) are formed after 80 min of elemental powders milling, the same values in the milled mixture are detected after only 15 min of treatment. Other substucture parameters in the milled elemental powders also differ of those in the milled for the same time mixture. It indicates that the solid state reaction (amorphization) occured during mixture milling influences the components substructure.