Grain boundary diffusion of 110mAg in polycrystalline Cu was measured in the type-B (962-675K) or type-C (565-452K) diffusion regimes (tables 78 and 79). In the former regime, the triple-product was found to obey the Arrhenius relationship:
sδD (m3/s) = 1.4 x 10-15 exp[-69.1(kJ/mol)/RT]
Measurements which were performed under C-type conditions showed that the grain-boundary diffusivity was described by:
D (m2/s) = 1.7 x 10-4 exp[-108.6(kJ/mol)/RT]
The data were analyzed in order to determine the factors which affected the curvature of the radiotracer profiles. Non-linear segregation was showed to have only a slight, or zero, effect. The initial portions of the profiles were well-described by taking account of grain boundary motion during diffusion annealing. The analysis showed that hypothetical dislocation-enhanced volume diffusion at low temperatures could not disturb the C-type conditions.
S.Divinski, M.Lohmann, C.Herzig: Acta Materialia, 2001, 49[2], 249–61
Table 80
Product of the Segregation Factor, Grain Boundary Diffusion
Coefficient, and Grain Boundary Width, for Au in Cu
Temperature (K) | P (m3/s) |
1036 | 1.33 x 10-19 |
983 | 9.63 x 10-20 |
945 | 5.38 x 10-20 |
898 | 5.80 x 10-20 |
865 | 2.69 x 10-20 |
844 | 2.74 x 10-20 |
786 | 9.31 x 10-21 |
739 | 2.99 x 10-21 |
666 | 9.23 x 10-22 |
618 | 2.61 x 10-22 |
526 | 2.09 x 10-24 |
515 | 2.65 x 10-24 |
471 | 4.62 x 10-26 |
450 | 5.79 x 10-27 |