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In the present work, high energy ball milling of binary ( Mg 2 Ni ) and ternary powder mixtures ( Mg 1.75 Nb 0.25 Ni and Mg 2 Ni 0.75 Nb 0.25, i.e., substitution of Nb for Mg and Ni , respectively) was carried out. The effects of milling process parameters on the microstructure of binary and ternary milled products were studied. Also, electrochemical properties of the nano-structured electrodes made from the milled products were measured. It was found that Nb substitution for Mg ( Mg 1.75 Nb 0.25 Ni ) has beneficial effect on the formation kinetic of Mg 2 Ni -based nano-crystallites. Electrode made from the 20h milled product using initial composition of Mg 1.75 Nb 0.25 Ni exhibited a high discharge capacity of ~600mAhg-1 and relatively longer discharge life. Such electrode showed a microstructure consisting of an amorphous core surrounded by nano-crystallites.

In this investigation, TiN/TiB2/TiAl nano-composite powder was produced by mechanical alloying technique and subsequent heat treatment. A powder mixture of Ti, BN, and Al with a molar ratio of 4:2:1 was milled for up to 70 h. Microstructures were studied and characterized using X-ray diffraction, scanning electron microscopy and energy-dispersive spectroscopy. The results indicated that TiN and TiB2-based phases were formed in an amorphous Ti (Al) matrix after 30 h of ball milling. With progression of the milling, the amorphous Ti (Al) solid solution is partially crystallized and the particle size reduced significantly. Subsequent annealing of the milled product at 600 °C for 0.5 h resulted in the transformation of the unstable amorphous Ti (Al) to TiAl crystal structure and formation of TiN/TiB2/TiAl nano-composite powder.

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