- Cocks, F.H. and Rose, R.M. and Wulff, J., Segregation of tantalum at very low concentrations in niobium by controlled solidification -- Neutron-activation study,
Journal of Less-Common Metals, vol. 10 no. 3
pp. 157 - 168 [0022-5088(66)90107-X] .
(last updated on 2007/04/10)
Equilibrium distribution coefficient for tantalum dissolved in columbium was found to be 1.4, and it decreased to slightly less than unity with addition of 1.5% titanium; effect of ingot geometry on segregation in normal freezing was analyzed; diffusion coefficient of tantalum in liquid columbium at about 2468 C (mp of columbium) was estimated to be of order of 4×10-4 sq mm/sec.