The isotope effect in self-diffusion was measured in the δ, γ and α phases of Fe by using the isotope pair: 52Fe and 59Fe (table 7). The isotope-effect data, together with measurements made of the effect of Co solute additions upon Fe self-diffusion (table 8), were used to deduce the most likely mechanisms for self-diffusion in all 3 phases. The data were consistent with a vacancy mechanism in face-centered cubic γ-Fe. In body-centered cubic α-Fe and δ-Fe, the data were consistent with a vacancy or interstitialcy mechanism. The mechanism seemed to be the same in δ-Fe and α-Fe.

C.M.Walter, N.L.Peterson: Physical Review, 1969, 178[3], 922–29

 

Table 6

Interdiffusion Coefficients for Cu in Fe

 

Temperature (K)

Interface Concentration (at%Cu)

D (m2/s)

1323

1.03

2.5 x 10-15

1323

2.34

2.8 x 10-15

1323

3.60

8.8 x 10-16

1323

4.67

7.6 x 10-16

1480

2.67

5.5 x 10-15

1480

4.30

6.9 x 10-15

1480

3.85

6.8 x 10-15

1480

4.78

5.0 x 10-15

1480

6.55

7.6 x 10-15

1583

1.83

1.2 x 10-14

1583

2.93

1.1 x 10-14

1583

4.24

2.0 x 10-14

1583

6.79

1.4 x 10-14

1583

8.40

1.7 x 10-14

1773

0.97

6.7 x 10-12

1773

1.92

5.5 x 10-12

1773

3.50

7.3 x 10-12

1773

3.66

3.1 x 10-12

1773

7.19

2.5 x 10-15