Energetic and kinetic evaluations conducted in a quasi-binary Cu-1 at% Co2Si alloy through DSC

Abstract

By means of differential scanning calorimetry (DSC) the precipitation process from a supersaturated solid solution of Cu−0.65 at% Co−0.33 at% Si (Cu−1 at% Co2Si) was investigated. On the basis of enthalpimetric calculations it was found that the decomposition begins with cobalt precipitation. Clustering of atoms of cobalt initiates the precipitation of silicon, and particles of the stoichiometric Co2Si composition are finally formed. Kinetic parameters were obtained by a convolution method based on the Mehl–Johnson–Avramiformalism. Their values are all in agreement with the experimentally observed behavior displayed by DSC traces. Decay kinetics of cobalt and silicon matrix during simulated isothermal calculations using DSC data reveals good agreement with similar computed results reported in literature. Precipitate dissolution obeys quite well to a three-dimensional diffusion kinetic law previously developed.