It was recalled that the weak concentration dependence of Ni diffusion in this material had been interpreted as being evidence for Ni diffusion via next-nearest neighbour jumps. This seemed to be reasonable, in view of the comparatively high enthalpy of formation in this alloy. Quasi-elastic neutron scattering and back-scattering spectrometry were used to study the elementary diffusion jumps of Ni in NiGa single crystals which contained 50at%Ni, and in polycrystals which contained 57 or 62at%Ni. The weak concentration-dependence of the Ni diffusion coefficient was confirmed over a wide concentration range on the Ni-rich site of the phase diagram (table 199, figure 35). The diffusive jumps of Ni atoms were proved to involve jumps via nearest-neighbour (antistructure) sites. In the case of the near-stoichiometric compositions, it was possible to determine directly the residence times of Ni atoms, at antistructure sites, from quasi-elastic neutron scattering data. The results were concluded to indicate the existence of very high defect concentrations near to the melting point.
M.Kaisermayr, J.Combet, H.Ipser, H.Schicketanz, B.Sepiol, G.Vogl: Physical Review B, 2000, 61[18], 12038-44
Table 187
Bulk Diffusion of 60Co in Monel 400
Temperature (K) | D (m2/s) |
1070 | 6.34 x 10-17 |
1110 | 1.82 x 10-16 |
1150 | 3.47 x 10-16 |
1200 | 1.72 x 10-15 |
1250 | 4.79 x 10-15 |
1300 | 8.91 x 10-15 |
1370 | 3.30 x 10-14 |
1470 | 1.78 x 10-13 |
1570 | 7.76 x 10-13 |
Figure 35
Diffusion of Ni in NiGa
Table 188
Grain Boundary Diffusion of 60Co in Monel 400
Temperature (K) | D (m2/s) |
700 | 1.62 x 10-16 |
740 | 6.56 x 10-16 |
780 | 2.75 x 10-15 |
820 | 7.76 x 10-15 |
860 | 2.69 x 10-14 |
900 | 5.34 x 10-14 |
960 | 1.86 x 10-13 |
1020 | 5.98 x 10-13 |
1100 | 2.07 x 10-12 |
Table 189
Bulk Diffusion of 64Cu in Monel 400
Temperature (K) | D (m2/s) |
1070 | 1.91 x 10-17 |
1120 | 6.41 x 10-17 |
1170 | 2.14 x 10-16 |
1220 | 3.83 x 10-15 |
1270 | 1.20 x 10-15 |
1370 | 1.55 x 10-14 |
1470 | 7.70 x 10-14 |
1570 | 2.34 x 10-13 |
Table 190
Grain Boundary Diffusion 64Cu in Monel 400
Temperature (K) | D (m2/s) |
700 | 4.49 x 10-17 |
750 | 4.20 x 10-16 |
800 | 1.29 x 10-15 |
continued
Table 190 (continued)
Grain Boundary Diffusion 64Cu in Monel 400
Temperature (K) | D (m2/s) |
700 | 4.49 x 10-17 |
750 | 4.20 x 10-16 |
800 | 1.29 x 10-15 |
Table 191
Diffusivity of Ni in Ni-Fe-Al Alloys
Fe (at%) | Al (at%) | Temperature (K) | D(m2/s) |
5.0 | 49.2 | 1530 | 8.8 x 10-15 |
5.0 | 49.2 | 1422 | 2.2 x 10-15 |
5.0 | 49.2 | 1362 | 7.7 x 10-16 |
5.0 | 49.2 | 1293 | 7.9 x 10-17 |
5.0 | 49.2 | 1243 | 6.2 x 10-17 |
5.0 | 49.2 | 1149 | 7.8 x 10-18 |
5.0 | 49.2 | 1093 | 2.2 x 10-18 |
5.0 | 49.2 | 1043 | 5.7 x 10-19 |
5.7 | 51.7 | 1362 | 1.5 x 10-15 |
5.7 | 51.7 | 1243 | 2.8 x 10-16 |
5.7 | 51.7 | 1181 | 6.7 x 10-17 |
5.7 | 51.7 | 1139 | 2.5 x 10-17 |
5.7 | 51.7 | 1093 | 5.8 x 10-18 |
5.7 | 51.7 | 1043 | 9.8 x 10-19 |
21.2 | 48.9 | 1422 | 1.1 x 10-15 |
21.2 | 48.9 | 1362 | 2.6 x 10-16 |
21.2 | 48.9 | 1293 | 1.3 x 10-16 |
21.2 | 48.9 | 1243 | 3.9 x 10-17 |
21.2 | 48.9 | 1181 | 6.2 x 10-18 |
21.2 | 48.9 | 1149 | 2.3 x 10-18 |
21.2 | 48.9 | 1093 | 3.4 x 10-19 |
21.2 | 48.9 | 1043 | 8.2 x 10-20 |
27.9 | 49.0 | 1422 | 6.2 x 10-15 |
continued
Table 191 (continued)
Diffusivity of Ni in Ni-Fe-Al Alloys
Fe (at%) | Al (at%) | Temperature (K) | D(m2/s) |
27.9 | 49.0 | 1362 | 2.0 x 10-15 |
27.9 | 49.0 | 1293 | 2.6 x 10-16 |
27.9 | 49.0 | 1243 | 1.3 x 10-16 |
27.9 | 49.0 | 1149 | 1.3 x 10-17 |
27.9 | 49.0 | 1093 | 2.5 x 10-18 |
27.9 | 49.0 | 1043 | 3.7 x 10-19 |
32.5 | 49.0 | 1530 | 4.8 x 10-14 |
32.5 | 49.0 | 1422 | 1.2 x 10-15 |
32.5 | 49.0 | 1362 | 3.1 x 10-16 |
32.5 | 49.0 | 1293 | 3.7 x 10-16 |
32.5 | 49.0 | 1243 | 5.8 x 10-17 |
32.5 | 49.0 | 1139 | 1.3 x 10-17 |
32.5 | 49.0 | 1093 | 2.4 x 10-18 |
32.5 | 49.0 | 1043 | 4.4 x 10-19 |
Table 192
Diffusivity of Carbon in Austenitic Ni-Fe-Cr
Cr(at%) | Fe(at%) | Temperature(K) | D (m2/s) |
0 | 0 | 843 | 1.76 x 10-14 |
0 | 0 | 913 | 9.05 x 10-14 |
0 | 0 | 983 | 3.62 x 10-13 |
0 | 0 | 1053 | 1.17 x 10-12 |
0 | 0 | 1123 | 3.59 x 10-12 |
0 | 21 | 843 | 1.21 x 10-14 |
0 | 21 | 913 | 7.47 x 10-14 |
0 | 21 | 983 | 3.51 x 10-13 |
0 | 21 | 1053 | 1.30 x 10-12 |
0 | 21 | 1123 | 3.58 x 10-12 |
0 | 42 | 843 | 2.07 x 10-14 |
0 | 42 | 913 | 1.33 x 10-13 |
continued
Table 192 (continued)
Diffusivity of Carbon in Austenitic Ni-Fe-Cr
Cr(at%) | Fe(at%) | Temperature(K) | D (m2/s) |
0 | 42 | 983 | 5.20 x 10-13 |
0 | 42 | 1053 | 1.67 x 10-12 |
0 | 42 | 1123 | 5.62 x 10-12 |
0 | 65 | 843 | 1.66 x 10-14 |
0 | 65 | 913 | 8.59 x 10-14 |
0 | 65 | 983 | 2.91 x 10-13 |
0 | 65 | 1053 | 9.93 x 10-13 |
0 | 65 | 1123 | 3.78 x 10-12 |
10 | 0 | 843 | 1.38 x 10-14 |
10 | 0 | 913 | 6.87 x 10-14 |
10 | 0 | 983 | 3.40 x 10-13 |
10 | 0 | 1053 | 1.06 x 10-12 |
10 | 0 | 1123 | 3.10 x 10-12 |
10 | 10 | 843 | 9.80 x 10-15 |
10 | 10 | 913 | 6.89 x 10-14 |
10 | 10 | 983 | 2.27 x 10-13 |
10 | 10 | 1053 | 8.04 x 10-13 |
10 | 10 | 1123 | 2.87 x 10-12 |
10 | 30 | 843 | 6.29 x 10-15 |
10 | 30 | 913 | 3.94 x 10-14 |
10 | 30 | 983 | 1.69 x 10-13 |
10 | 30 | 1053 | 7.23 x 10-13 |
10 | 30 | 1123 | 2.74 x 10-12 |
20 | 0 | 843 | 3.74 x 10-15 |
20 | 0 | 913 | 2.38 x 10-14 |
20 | 0 | 983 | 1.19 x 10-13 |
20 | 0 | 1053 | 4.45 x 10-13 |
20 | 0 | 1123 | 1.75 x 10-12 |
20 | 10 | 843 | 2.07 x 10-15 |
20 | 10 | 913 | 1.78 x 10-14 |
continued
Table 192 (continued)
Diffusivity of Carbon in Austenitic Ni-Fe-Cr
Cr(at%) | Fe(at%) | Temperature(K) | D (m2/s) |
20 | 10 | 983 | 9.09 x 10-14 |
20 | 10 | 1053 | 3.68 x 10-13 |
20 | 10 | 1123 | 1.48 x 10-12 |
20 | 39 | 843 | 1.12 x 10-15 |
20 | 39 | 913 | 9.61 x 10-15 |
20 | 39 | 983 | 8.02 x 10-14 |
20 | 39 | 1053 | 3.22 x 10-13 |
20 | 39 | 1123 | 1.05 x 10-15 |
30 | 0 | 843 | 1.65 x 10-15 |
30 | 0 | 913 | 8.33 x 10-15 |
30 | 0 | 983 | 4.80 x 10-14 |
30 | 0 | 1053 | 1.67 x 10-13 |
30 | 0 | 1123 | 5.55 x 10-13 |