An experimental study was made of Ni diffusion, in single-grained samples of an icosahedral quasicrystalline compound, at 699 to 1074K. A radiotracer technique, together with serial sectioning, was used to determine the concentration versus depth profiles. No deviation from Arrhenius behaviour was detected over the present temperature range, and the results (table 61, figure 7) could be described by:

D (m2/s) = 5.3 x 10-3 exp[-209(kJ/mol)/RT]

The most interesting observation was that Ni diffusion, and the diffusion of other transition-metal elements, was much slower than the diffusion of elements such as Ge and Zn. The activation enthalpies for the diffusion of transition-metal elements were also considerably greater than those found for non-transition metal elements. It was concluded that the diffusion of Ni atoms was most likely to proceed via a vacancy mechanism over Al and Pd sites.

T.Zumkley, H.Nakajima, T.A.Lograsso: Philosophical Magazine A, 2000, 80[5], 1065-74. See also: Materials Science and Engineering A, 2001, 294-296, 702-5

 

Table 49

Interdiffusion Coefficients in Al-Based Systems at 813K

 

System

Interdiffusion Coefficient

Magnitude (m2/s)

Al-Cu

DCuCu

1.33 x 10-13

Al-Mg

DMgMg

4.22 x 10-13

Al-Ag

DAgAg

2.73 x 10-13

Al-Cu-Mg

DCuCu

1.55 x 10-13

Al-Cu-Mg

DMgMg

4.39 x 10-13

continued

  Table 49 (continued)

Interdiffusion Coefficients in Al-Based Systems at 813K

 

System

Interdiffusion Coefficient

Magnitude (m2/s)

Al-Cu-Mg

DCuMg

1.80 x 10-14

Al-Cu-Mg

DMgCu

3.50 x 10-14

Al-Cu-Mg-Ag

DCuCu

2.94 x 10-13

Al-Cu-Mg-Ag

DMgMg

4.17 x 10-13

Al-Cu-Mg-Ag

DAgAg

3.40 x 10-13

Al-Cu-Mg-Ag

DCuMg

1.20 x 10-14

Al-Cu-Mg-Ag

DMgCu

5.50 x 10-14

Al-Cu-Mg-Ag

DMgAg

5.00 x 10-16

Al-Cu-Mg-Ag

DAgMg

5.60 x 10-14

 

Table 50

Diffusion Parameters for the Al-Cu-Mg System

 

Pressure (MPa)

Do (m2/s)

ECuCu (kJ/mol)

0.101

4.2 x 10-5

132

1000

1.9 x 10-5

137

2000

9.0 x 10-6

143

3000

5.0 x 10-6

149

 

Table 51

Diffusion Parameters for the Al-Cu-Mg System

 

Pressure (MPa)

Do (m2/s)

EMgMg (kJ/mol)

0.101

6.9 x 10-5

128

1000

4.9 x 10-5

136

2000

3.4 x 10-5

144

3000

2.4 x 10-5

152

 

Table 52

Diffusion Parameters for the Al-Cu-Mg System

 

Pressure(MPa)

Do (m2/s)

EMg(Al-Cu)(kJ/mol)

0.101

2.1 x 10-5

120

1000

2.7 x 10-5

133

2000

3.5 x 10-5

144

3000

4.4 x 10-5

157

 

Table 53

Interdiffusion Coefficients in the Al-Cu-Zn System

as a Function of Temperature and Pressure

 

Pressure (MPa)

Temperature (K)

DCuCuAl (m2/s)

0.101

815

1.4 x 10-13

0.101

830

2.0 x 10-13

0.101

845

2.8 x 10-13

0.101

860

4.0 x 10-13

2000

815

6.6 x 10-15

2000

830

9.6 x 10-15

2000

845

1.4 x 10-14

2000

860

2.0 x 10-14

2800

815

2.0 x 10-15

2800

830

3.1 x 10-15

2800

845

4.1 x 10-15

2800

860

6.7 x 10-15

 

 

Table 54

Interdiffusion Coefficients in the Al-Cu-Zn System

as a Function of Temperature and Pressure

 

Pressure (MPa)

Temperature (K)

DZnCuAl (m2/s)

0.101

815

-8.0 x 10-14

0.101

830

-7.6 x 10-15

0.101

845

-2.5 x 10-13

0.101

860

5.6 x 10-13

2000

815

-9.8 x 10-16

2000

830

1.2 x 10-14

2000

845

1.3 x 10-14

2000

860

-1.4 x 10-14

2800

815

-3.2 x 10-15

2800

830

8.6 x 10-15

2800

845

-2.8 x 10-15

2800

860

-7.5 x 10-15

Table 55

Interdiffusion Coefficients in the Al-Cu-Zn System

as a Function of Temperature and Pressure

 

Pressure (MPa)

Temperature (K)

DCuZnAl (m2/s)

0.101

815

-3.6 x 10-15

0.101

830

-2.1 x 10-15

0.101

845

6.8 x 10-15

0.101

860

-5.2 x 10-15

2000

815

1.3 x 10-16

2000

830

1.7 x 10-15

2000

845

-2.0 x 10-15

2000

860

-2.7 x 10-15

2800

815

-1.7 x 10-17

2800

830

2.4 x 10-16

2800

845

-5.7 x 10-16

2800

860

-1.6 x 10-16

 

 

Table 56

Interdiffusion Coefficients in the Al-Cu-Zn System

as a Function of Temperature and Pressure

 

Pressure (MPa)

Temperature (K)

DZnZnAl (m2/s)

0.101

815

4.2 x 10-13

0.101

830

5.9 x 10-13

0.101

845

7.6 x 10-13

0.101

860

1.2 x 10-12

2000

815

2.5 x 10-14

2000

830

3.5 x 10-14

2000

845

5.0 x 10-14

2000

860

7.5 x 10-14

2800

815

7.7 x 10-15

2800

830

1.2 x 10-14

2800

845

1.4 x 10-14

2800

860

2.7 x 10-14

Figure 6

Diffusivity of 60Co in Al72.2Ni11.8Co16.0

(Filled circles: parallel to c-direction, Open circles: perpendicular to c-direction)

 

Table 57

Interdiffusion in Al3Fe

 

Temperature (C)

D (cm2/s)

900

2.8 x 10-9

950

9.2 x 10-9

1000

1.9 x 10-8

1050

5.1 x 10-8

 

Table 58

Effective Diffusivity in Al-Li Alloys

 

Temperature (C)

Li (at%)

D (m2/s)

150

7.6

8.02 x 10-21

150

9.8

6.04 x 10-21

170

7.6

2.07 x 10-20

170

9.8

1.81 x 10-20

  Table 59

Diffusivity of 60Co in Al72.2Ni11.8Co16.0 (Tenfold Direction)

 

Temperature (K)

Diffusivity (m2/s)

803

1.64 x 10-19

870

3.55 x 10-18

923

2.73 x 10-17

971

1.82 x 10-16

993

3.61 x 10-16

1021

1.05 x 10-15

1079

5.50 x 10-15

1144

3.20 x 10-14

1210

1.55 x 10-13

 

Table 60

Diffusivity of 60Co in Al72.2Ni11.8Co16.0 (Twofold Direction)

 

Temperature (K)

Diffusivity (m2/s)

803

5.60 x 10-20

876

2.40 x 10-18

923

1.90 x 10-17

971

1.03 x 10-16

997

2.42 x 10-16

1025

7.50 x 10-16

1079

4.41 x 10-15

1144

2.69 x 10-14

1210

1.47 x 10-13

 

Table 61

Diffusivity of 63Ni in Al70Pd21Mn9

 

Temperature (K)

D (m2/s)

699

6.96 x 10-19

774

3.04 x 10-17

870

1.68 x 10-15

960

2.34 x 10-14

1012

7.96 x 10-14

1074

3.63 x 10-13

Figure 7

Diffusivity of 63Ni in Al70Pd21Mn9