Migration in the amorphous alloy was studied, at temperatures of between 575 and 643K, by using secondary ion mass spectrometry. The measurements were performed on pre-relaxed specimens, and it was found that the diffusion coefficients lay between 10-23 and 2 x 10-20m2/s. The results (table 77) could be described by:

Be:     D (m2/s) = 9.4 x 10-4exp[-2.16(eV)/kT]

Si:     D (m2/s) = 7.0 x 105exp[-3.39(eV)/kT]

It was suggested that the diffusion mechanism involved the cooperative motion of groups of atoms.

S.K.Sharma, M.P.Macht, V.Naundorf: Acta Metallurgica et Materialia, 1992, 40[9], 2439-49

 

Table 77

Diffusion of Be and Si in Fe40Ni40B20

Diffusant

Temperature (K)

D (m2/s)

Be

575

1.0 x 10-22

Be

588

2.7 x 10-22

Be

592

4.6 x 10-22

Be

603

7.6 x 10-22

Be

613

1.6 x 10-21

Be

618

1.8 x 10-21

Be

620

2.7 x 10-21

Be

634

7.4 x 10-21

Be

638

6.3 x 10-21

Be

643

1.2 x 10-20

Si

593

1.4 x 10-23

Si

603

2.3 x 10-23

Si

609

7.1 x 10-23

Si

613

7.0 x 10-23

Si

632

5.3 x 10-22

Si

634

8.4 x 10-22

Si

643

7.1 x 10-21