Investigation of the Effect of Milling Time on Elemental Powders of Oxi-Reduction Nickel and Hydrogenation : Dehydrogenation Titanium

ABSTRACT: Mechanical alloying (MA) is widely applied in the synthesis of blended elemental or prealloyed powders. This work evaluates the effect of milling time on elemental nickel and titanium powders produced by oxi-reduction and the hydrogenation-dehydrogenation process, respectively. The powders are characterized by scanning electron microscopy, X-ray diffraction, particle size, powder yield, and differential scanning calorimetry. It is observed that increasing the milling time promotes the formation of a structure composed of thin lamellae of nickel and titanium, which results in the beneficial effect of lowering the temperature for the formation of the intermetallic of the Ni-Ti system and in the powder yield achieved. The reduction of milling time in the MA process of NiTi alloys enhances technological efficiency by decreasing their overall processing time.