Accession Number : AD0690710

Title :   ELASTIC AND ANELASTIC BEHAVIOR DURING THE MARTENSITIC TRANSFORMATION IN INDIUM-THALLIUM ALLOYS,

Corporate Author : DEFENCE RESEARCH ESTABLISHMENT TORONTO DOWNSVIEW (ONTARIO)

Personal Author(s) : DE Morton,M. E.

Report Date : 26 AUG 1968

Pagination or Media Count : 5

Abstract : Measurement of internal friction in In-rich In-Tl alloys has shown an amplitude-dependent peak associated with the martensitic transformation. The peak is thermally activated when the transformation occurs near the melting point Tm, but not at lower temperatures. It is suggested that the peaks originate from the stress-assisted motion of twin boundaries that are known to spontaneously coalesce immediately below the transformation temperature. The activation energy associated with the transformation peak near Tm is 10-13 kcal/mole higher than for the diffusion of Tl in In. A mechanism is proposed for this relaxation, invoking an interaction between twin boundaries and solute, whereby reordering of solute is effected in differently orientated tetragonal regions by twin-boundary motion. (Author)

Descriptors :   (*INDIUM ALLOYS, PHASE STUDIES), (*THALLIUM ALLOYS, PHASE STUDIES), MARTENSITE, MICROSTRUCTURE, STRESSES, STRAIN(MECHANICS), INTERNAL FRICTION, CANADA

Subject Categories : Properties of Metals and Alloys
      Solid State Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE