The parameters of phase separation in NT-50 alloy calculated from the internal friction kinetics

An analytical expression for the internal friction kinetics Q(-1)(t) in the course of isothermal aging is obtained for a Nb-(48.5 +/- 1.5%)Ti alloy. The numerical analysis of anomalies of the Q(-1)(t) function showed that, during the first three hours of annealing at 300 and 375degreesC, the alpha-Ti phase is separated in a single stage without the formation of intermediate alpha(') alpha(''), or omega phases. Using the experimental curves of Q(-1)(t), the values of parameters (K and n) are determined for the Avrami equation describing the kinetics of alpha-Ti phase separation. (C) 2004 MAIK "Nauka / Interperiodica".