Accession Number : AD0673301

Title :   THE EFFECT OF STRESS ON SOLID STATE PHASE TRANSFORMATIONS.

Descriptive Note : Final rept. 10 Nov 64-31 Aug 68,

Corporate Author : ILLINOIS UNIV URBANA DEPT OF MINING METALLURGY AND PETROLEUM ENGINEERING

Personal Author(s) : Altstetter,Carl J.

Report Date : 02 SEP 1968

Pagination or Media Count : 7

Abstract : The objective of this research was to gain a better understanding of the factors which control the occurrence and characteristics of martensitic transformations. A very simple transformation was chosen -- face-centered cubic to hexagonal close packed -- because it offered the best opportunity to understand the mechanism. The shears which take place may be attributed to the passage of Shockley partial dislocations over every other close-packed plane. There is a well-developed body of knowledge about the movement of dislocations under stress, to effect slip and twinning. It was hoped that the effect of stress on the martensitic transformation could be interpreted in terms of what is known about slip and twinning. Transformation in cobalt, and cobalt-nickel single and polycrystals was carried out under a series of applied stresses. Transformations in carium and lanthanum polycrystals were studied by x-ray diffraction, dilatometry and metallographic techniques. (Author)

Descriptors :   (*CRYSTALLOGRAPHY, PHASE STUDIES), TWINNING(CRYSTALLOGRAPHY), DISLOCATIONS, CRYSTAL LATTICES, COBALT, NICKEL, LANTHANUM, CERIUM, SHEAR STRESSES, MARTENSITE, TRANSFORMATIONS, METALLOGRAPHY, ELECTRON MICROSCOPY, X RAY DIFFRACTION

Subject Categories : Properties of Metals and Alloys
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE