DID YOU KNOW? DTIC has over 3.5 million final reports on DoD funded research, development, test, and evaluation activities available to our registered users. Click HERE
to register or log in.
ANELASTIC MEASUREMENTS OF POINT DEFECTS.
Summary technical rept.,
ILLINOIS UNIV AT URBANA
Pagination or Media Count:
Lattice defects and diffusion of atoms in several transition metal alloys have been examined using anelastic and magnetic measuring methods. In pure nickel phenomena associated with vacancies and divacancies have been observed. The thermodynamic properties of these defects have been determined. In nickel-carbon alloys an associated C-C pair has been identified and some of its motional properties determined. A similar C-C pair in the fcc phase of cobalt has been examined extensively. Not only have the parameters describing its diffusion been deduced, but also the probable symmetry axis, 100, has been determined. The tumbling of Ti-Ti substitutional pairs in dilute concentration in cobalt has also been observed. Detailed analysis of the results leads to the conclusion that the pairs responsible for the relaxation occupy next nearest neighbor lattice positions in the crystal. Both the motional energy and the binding energy of the pairs have been determined. Finally, the precipitation out of solid solution of N in deformed Nb has been followed by internal friction techniques. These measurements have been correlated with changes in hardness and yield strength during precipitation. The system shows unusual strain aging effects which will require careful electron microscopy for full understanding. Author
APPROVED FOR PUBLIC RELEASE