Carbon diffusion in alloys of titanium-scandium-carbon system

Diffusion mobility of carbon was studied in Ti-Sc-C alloys with scandium amounts of 5 to 80at.% and carbon contents of 0.25 and 0.5 at.%. Radioactive carbon was placed on the sample surface and layer-by-layer radiometric analysis was carried out for samples annealed at 1223 and 1373 K. Then coefficients of carbon diffusion were calculated and their concentration dependence was plotted for the alloys studied. Changes of carbon content were found not to affect diffusion coefficients, while scandium content increase resulted in carbon diffusion coefficient decrease. It can be explained by different distribution of electrons over external shells in titanium and scandium atoms