Grain-Boundary Diffusion of Zinc in Copper Measured by the Electron-Probe Microanalyzer

Grain-boundary and lattice diffusion of zinc vapor into copper at 550°C were measured with the electron-probe microanalyzer and the results were used to calculate the diffusion coefficients. The lattice diffusion coefficient DL increases from 5×10−13 to 3×10−11 over the concentration range from 2 to 27.5 atomic percent zinc. Over the same concentration range, the grain boundary diffusion coefficient DB changes from 1×10−7 to 7×10−6. The ratio of grain boundary diffiusion coefficient to lattice diffusion DB/DL remains at approximately 106.