The O diffusivity was deduced from emf measurements performed on solid electrolytic cells at 873 to 1373K. It was found that O diffusion in Ta alloys was slightly decreased by small metallic additions. Several % of W had a great effect in decreasing the O diffusivity (table 266).

J.S.Lee, C.J.Altstetter: Acta Metallurgica, 1986, 34[1], 131-8

 

Table 266

Parameters for O Diffusion in Ta-W Alloys

 

W (at%)

O(at%)

ln Do(m2/s)

E (kJ/mol)

9.0

0.4

-13.59

123

10.2

1.4

-11.67

144