Kinetics of Aging Precipitation of CuCr Alloy by Rapidly Solidification

Abstract:

Supersaturated CuCr solid solution was prepared by pulverization. After that, the aging dynamics were analyzed at different temperatures. The results showed that the G.P zone was presented at relatively low temperature. We could observe a coherent interface between precipitated phase and matrix. The results that were obtained both from transmission electron microscope (TEM) and Electron Energy Disperse Spectroscopy (EDS) revealed that as aging time increased, the amount of Cr metal phase also increased due to solute enrichment process. On the other hand, the activation energy for atomic diffusion was reduced at high temperature. As a result, the metal phases of Cr were formed very fast. The fractional volume of the precipitated phase was measured by EDS and then applied Avrami equation to analyze the dynamical effect of aging. Finally we concluded that the phase transition in CuCr alloy was determined by aging dynamics and diffusion was the most important effect of aging process, other factors such as solute species, impurities, vacancies, dislocations, grain boundaries and lattice distortions may be affected this process, too.

Key words:Cu alloy; phase transition dynamics; diffusion; CuCr solid solution; conductivity