The inhibition of the chemically induced migration at high temperature has been investigated in Co-Cu alloy. 80Co-20Cu (wt.%) specimens have been sintered for 20h and heat-treated after adding Cu-Co-Sn powder mixtures of various compositions at 1150℃ and 1300℃. In the specimen heat-treated at 1300℃ with the mixture of 10wt.% Sn, migration does not occur. However, when the Sn content is higher or the heat-treatment temperature is lower at 1150℃, the migration occurs. The inhibition of migration can be explained by the decrease of the coherency strain energy that is the driving force for migration, resulting from coherency breaking because of high D/v (D is the lattice diffusivity of solute and v is the migration velocity of interface) value.
