Studies on the crystallization kinetics of Cu-reinforced partially crystalline Cu47Ti33Zr11Ni8Si1 metallic glass composite

The crystallization kinetics of partially crystalline Cu47Ti33Zr11Ni8Si1 gas atomized powder (GAP) and composites was studied by differential scanning calorimetry. The activation energy for crystallization as determined by the Kissinger equation is nearly equal for the particle-free powder (3.43 +/- 0.40 eV) and the composite (3.11 +/- 0.22 eV). The activation energy of crystallization derived from isothermal annealing experiments is nearly similar for the GAP (4.53 +/- 0.40 eV) and the composite (4.25 +/- 0.40 eV). The values of the Avrami exponent suggest that the crystallization is diffusion controlled. The local Avrami exponent suggests that surface nucleation is active in GAP but bulk crystallization dominates in milled composite powder. (C) 2006 Elsevier B.V. All rights reserved.