Study of precipitation phenomena in alloys by nuclear magnetic resonance

The nuclear magnetic resonance of Co⁵⁹nuclei in precipitates from Cu-3.52%Co and Cu-19%Ni-18%Co alloy powders aged at 600°C after solution heat treatments has been observed with a pulsed technique. The observed spinecho spectra for the Cu-3.52%Co alloy indicate that the precipitates have f.c.c. structure and their Cu concentrations are extremely small. In the case of the Cu-19%Ni-18%Co alloy, the observed distribution of resonance frequencies suggests that a completely random solid solution cannot be obtained by quenching and that concentration fluctuations exist in this alloy even immediately after quenching from 1075°C.