Showing papers on "Ferroelasticity published in 1972"

Lattice Softening, Phase Stability and Elastic Anomaly of the β-Au–Cu–Zn Alloys

Abstract: The β-Au x Cu 1- x Zn alloys transform martensitically from a Heusler-type ordered structure (b. c. c.) into an orthorhombic crystal at lower temperatures. The phase stability associated with the transformation was investigated by an examination of the elastic constants in the Heusler phase. The shear constant ( C 11 – C 12 )/2 approaches zero near the martensite temperature, and its temperature coefficient is positive in the region above martensite temperature. Thus the transformation in these alloys proved itself to be deeply connected with a lattice softening and the elastic anisotropy. The free energy difference between the Heusler and the martensite phases mainly comes from the change in vibrational entropy, which can explain the thermoelastic property of the transformation. Pseudoelastic properties including ferroelasticity and the memory effect of these alloys were also investigated from their strain-stress diagrams. The properties have a close relation to the large elastic anisotropy and the latti...

Shubnikov point groups and the property of `ferroelasticity'

Abstract: Previously the concept of ferroelasticity, introduced by Aizu, has only been studied in connexion with classical point groups. In this paper the use of this concept is extended to the Shubnikov point groups; this is important in connexion with ferroelectric phase transitions and various kinds of magnetic phase transition. Tables are given which enable all ferroelastic species to be identified.