Reerystallization behaviour of a Ni3Al (B, Zr) alloy

A Ni3Al (B, Zr) alloy, cold rolled 73% at room temperature, was subjected to isothermal recrystallization annealing at temperatures ranging between 800degreesC and 1200degreesC. The recrystallization kinetics suggested a two stage process. The average activation energies for the two stages were 117 kJ/mole and 274 kJ/mole respectively, The Avrami exponent n also has two different sets of values at the two stages. It was suggested that these are related to the initial recrystasllization of the disordered Ni-rich gamma phase, followed by that of the ordered Ni3Al(gamma')phase.