Enthalpy of nickel-aluminum reaction

CHED 1166

Amanda L. Henderson, gryko@jsu.edu and Jan Gryko, gryko@jsu.edu. Department of Physical and Earth Sciences, Jacksonville State University, 700 N. Pelham Rd, Jacksonville, AL 36265
Nickel reacts with aluminum forming Ni-Al compound. This exothermic reaction liberates a large quantity of heat, and the temperature of the reacting mixture reaches 2000 oC . We have studied the enthalpy of this reaction, using density functional theory and the Abinit package. The optimized lattice constant of Ni-Al alloy is within 3 – 4 % of the experimental value of 2.874 Å. The nickel-aluminum distance in Ni-Al is the same as the Ni-Ni distance in nickel, which is 2.489 Å. The density of electron states of Ni-Al alloy indicates that nickel d band is filled during the formation of Ni-Al alloy, which results in a large thermal effect observed experimentally.