The grain-boundary diffusion of Au was measured in Cu bicrystals, with symmetrical near-Σ5, 36.9º (310)[001] coincidence-site lattice tilt grain boundaries, by using radiotracer and serial sectioning techniques. The orientations of the bicrystals were precisely determined by using the Kossel technique, and all 3 macroscopic parameters which described the orientations were evaluated. The tilt angles ranged from 33.21 to 39.26º. The grain-boundary diffusion of 195Au was measured as a function of the tilt angle and temperature (tables 37 and 38). At temperatures ranging from 661 to 1030K, the orientation-dependence of the radiotracer exhibited a characteristic cusp. This was slightly below the ideal Σ = 5 coincidence-site lattice grain boundary. The activation enthalpy and frequency factor, as determined from lower-temperature data, exhibited a maximum slightly below the ideal Σ = 5 coincidence-site lattice grain boundary. A negative deviation from a straight Arrhenius plot was observed with increasing temperature. This reflected a change in the grain boundary structure at temperatures above 800K.
E.Budke, T.Surholt, S.I.Prokofjev, L.S.Shvindlerman, C.Herzig: Acta Materialia, 1999, 47[2], 385-95
Table 37
Diffusivity of 195Au in Cu along [001] Tilt Grain Boundaries
near to Σ = 5, 36.9º (310)[001]
Temperature (K) | Tilt Angle (º)* | sδD (m3/s) |
661 | 33.21 | 3.54 x 10-21 |
661 | 35.10 | 5.83 x 10-21 |
661 | 35.19 | 8.52 x 10-21 |
661 | 35.88 | 7.65 x 10-21 |
661 | 36.00 | 6.12 x 10-21 |
661 | 36.26 | 2.83 x 10-21 |
661 | 36.53 | 1.51 x 10-21 |
661 | 36.67 | 9.50 x 10-21 |
661 | 37.57 | 1.98 x 10-20 |
661 | 37.74 | 2.53 x 10-20 |
661 | 38.12 | 1.28 x 10-20 |
661 | 39.26 | 7.71 x 10-21 |
780 | 33.21 | 2.96 x 10-20 |
780 | 35.10 | 4.52 x 10-20 |
780 | 35.19 | 4.53 x 10-20 |
780 | 35.88 | 5.44 x 10-20 |
780 | 36.00 | 3.76 x 10-20 |
780 | 36.26 | 2.70 x 10-20 |
780 | 36.53 | 1.81 x 10-20 |
780 | 36.67 | 5.13 x 10-20 |
780 | 36.97 | 6.08 x 10-20 |
Table 37 (continued)
Diffusivity of 195Au in Cu along [001] Tilt Grain Boundaries
near to Σ = 5, 36.9º (310)[001]
Temperature (K) | Tilt Angle (º)* | sδD (m3/s) |
780 | 37.20 | 6.56 x 10-20 |
780 | 37.45 | 7.33 x 10-20 |
780 | 37.57 | 6.19 x 10-20 |
780 | 37.74 | 8.93 x 10-20 |
780 | 38.12 | 6.18 x 10-20 |
780 | 39.26 | 5.18 x 10-20 |
868 | 35.10 | 7.09 x 10-20 |
868 | 35.19 | 8.03 x 10-20 |
868 | 36.00 | 8.45 x 10-20 |
868 | 36.26 | 8.44 x 10-20 |
868 | 37.20 | 8.50 x 10-20 |
868 | 37.57 | 1.17 x 10-19 |
868 | 39.26 | 9.38 x 10-20 |
872 | 33.21 | 8.61 x 10-20 |
872 | 33.60 | 7.28 x 10-20 |
872 | 35.88 | 1.23 x 10-19 |
872 | 36.26 | 1.15 x 10-19 |
872 | 36.53 | 7.01 x 10-20 |
872 | 36.67 | 1.46 x 10-19 |
872 | 38.12 | 1.41 x 10-19 |
978 | 33.21 | 1.80 x 10-19 |
978 | 35.19 | 1.65 x 10-19 |
978 | 35.88 | 1.44 x 10-19 |
978 | 36.00 | 2.03 x 10-19 |
978 | 36.26 | 1.88 x 10-19 |
978 | 36.53 | 1.31 x 10-19 |
978 | 36.67 | 2.18 x 10-19 |
978 | 37.57 | 2.23 x 10-19 |
Table 37 (continued)
Diffusivity of 195Au in Cu along [001] Tilt Grain Boundaries
near to Σ = 5, 36.9º (310)[001]
Temperature (K) | Tilt Angle (º)* | sδD (m3/s) |
978 | 37.74 | 2.77 x 10-19 |
978 | 38.12 | 2.42 x 10-19 |
978 | 39.26 | 1.87 x 10-19 |
1030 | 33.21 | 2.45 x 10-19 |
1030 | 35.10 | 2.37 x 10-19 |
1030 | 35.19 | 2.52 x 10-19 |
1030 | 35.88 | 2.18 x 10-19 |
1030 | 36.00 | 2.65 x 10-19 |
1030 | 36.26 | 2.40 x 10-19 |
1030 | 36.53 | 1.86 x 10-19 |
1030 | 36.67 | 3.24 x 10-19 |
1030 | 37.57 | 3.62 x 10-19 |
1030 | 37.74 | 3.42 x 10-19 |
1030 | 38.12 | 3.38 x 10-19 |
1030 | 39.26 | 2.72 x 10-19 |
with respect to the [001] axis