NUCLEATION AND COARSENING OF Co-RICH α-PHASE IN THE COPPER-COBALT SYSTEM

The kinesics of the early stages of the decomposition reaction in a Cu-1.75at.% Co solid solution aged at 853K were investigated with APFIM (Atom Probe Field Ior Microscopy) and TEM (Transmission Electron Microscopy). The radius of the critical nucleus of α-phase was revealed to be about 0.8nm. The Co-concentration in the fine precipitates was determined to be (95±2)at.%. The results were interpreted in terms of Kampmann-Wagner numerical model for the kinetics of nucleation and growth decomposition in solids.