Intrinsic diffusivities and the Kirkendall effect were investigated in Ni-Pd solid solutions at 900 to 1200C, and 1100C, respectively (tables 204 to 206, figure 36). Couple techniques were used, including incremental and multi-foil types. A theoretical analysis

of the Kirkendall effect was performed for a binary solid solution system. It was demonstrated that, depending upon the relative mobilities of the components in different parts of the interaction zone of binary diffusion couples, the appearance of 2 or more Kirkendall planes was to be expected. This phenomenon was predicted, and observed, in multi-phase Ni-Ti diffusion couple. It was not observed in experiments on single-phase Ni-Pd and Fe-Pd systems.

M.J.H.Van Dal, M.C.L.P.Pleumeekers, A.A.Kodentsov, F.J.J.Van Loo: Acta Materialia, 2000, 48[2], 385-96

 

Table 205

Intrinsic Diffusion of Ni in Ni-Pd at 1100C

 

Ni (at%)

Couple

D (m2/s)

6.6

multi-foil

3.3 x 10-15

13

multi-foil

6.9 x 10-15

17.6*

incremental

1.8 x 10-14

25

multi-foil

1.98 x 10-14

37

multi-foil

3.53 x 10-14

40.3*

incremental

4.9 x 10-14

48

multi-foil

3.74 x 10-14

51.6*

incremental

3.4 x 10-14

58

multi-foil

2.97 x 10-14

58.5*

incremental

3.3 x 10-14

68

multi-foil

1.98 x 10-14

77

multi-foil

7.2 x 10-15

82.6*

incremental

3.8 x 10-15

85

multi-foil

2.2 x 10-15

92

multi-foil

1.5 x 10-15

*concentration at the Kirkendall plane