Accession Number : AD0829681

Title :   ANELASTIC MEASUREMENTS OF POINT DEFECTS.

Descriptive Note : Summary technical rept.,

Corporate Author : ILLINOIS UNIV AT URBANA

Personal Author(s) : Wert, C. A. ; Birnbaum, H. K.

Report Date : FEB 1968

Pagination or Media Count : 20

Abstract : 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)

Descriptors :   *ALLOYS), (*TRANSITION METALS, ALLOYS), (*CRYSTAL DEFECTS, NICKEL, NICKEL ALLOYS, CARBON ALLOYS, COBALT ALLOYS, TITANIUM ALLOYS, HARDNESS, YIELD POINT, MAGNETIC PROPERTIES, DIFFUSION, SYMMETRY(CRYSTALLOGRAPHY), SOLID SOLUTIONS, INTERNAL FRICTION, AGING(MATERIALS), TRANSITION TEMPERATURE, QUENCHING.

Subject Categories : Inorganic Chemistry
      Metallurgy and Metallography
      Crystallography

Distribution Statement : APPROVED FOR PUBLIC RELEASE