Cu Diffusion Along Al Grain Boundaries

Grain boundary diffusion of copper (GBD) in aluminum was investigated by EPMA in the temperature range from 300 to 400 degrees C. The triple product s delta D(gb) (s-segregation coefficient, delta - grain boundary width, D(gb) - GBD coefficient) was calculated using Fisher-Gibbs solution methods - by measuring of GB copper concentration as a functional penetration depth and the contour angle (at the top of diffusion wedge). In the first case s delta D(gb) = 5.1.10(-11) m(3)/s.exp(-102 kJ/mol/RT) and in the second case s delta D(gb) = 1.4.10(-11) m(3)/s.exp(-94 kJ/mol/RT)