Crystallization kinetics of Ni-P glass ? activation energies for nucleation and growth of nuclei

Abstract

A pre-anneal treatment was introduced to a melt-spun Ni-P alloy. By crystallizing the asquenched and pre-annealed samples in a differential scanning calorimeter at different heating rates and isothermal process, the apparent activation energies for the total crystallization of the Ni-P samples were obtained by using the Kissinger technique and the Arrhenius relation. It was found that the apparent activation energy, E c, decreased and tended to a certain value of 180 kJ mol−1, with increase of pre-anneal time. According to the classical phase transformation theory, the activation energies for nucleation and growth of nuclei in the Ni-P glasses were deduced to be 324 and 180 kJ mol−1, respectively, which are very close to the values previously reported by our laboratory. The weight parameters of nucleation, a, and growth, b, decrease monotonically and increase and tend to certain values with an increase of pre-anneal time, respectively.