Effect of milling variables on the synthesis of NiAl intermetallic compound by mechanical alloying

NiAl intermetallic compound was synthesized by mechanical alloying of elemental mixtures of Ni and Al powders in a Spex mill. The compound formation took place according to a mechanically induced self-propagating reaction (MSR), and the influence of milling variables on its ignition time was determined using a factorial design. Results indicated ignition time as a function of initial particle size of Ni, process control agent, and ball-to-powder ratio. Also, an interaction between ball-to-powder ratio, process control agent, and a set of balls was found to control the average particle size of as-milled powders.