T. Grosdidier et Mj. Philippe, Deformation induced martensite and superelasticity in a beta-metastable titanium alloy, MAT SCI E A, 291(1-2), 2000, pp. 218-223
This work investigates the formation of deformation induced martensite and
shape-memory effects of water quenched P-rich microstructures of a beta met
astable titanium alloy denominated beta-Cez (developed by the Cezus company
). In highly beta metastable microstructures - solution treatments for 1 h
at 920 (beta domain) or 860 degrees C (alpha+beta domain) - the beta phase
transforms to a martensite that is stress-assisted in nature. Solution trea
tment at a slightly lower temperature (850 degrees C) increases the stabili
ty of the beta phase and the martensite thus becomes a strain-induced type.
Decreasing the solution treatment temperature further (800 degrees C) lead
s to a sufficiently stable beta phase so that no martensite is formed under
tensile deformation and only slip is activated. These different ways of ac
commodating deformation result in various mechanical responses. In particul
ar, the stress-assisted martensite in this alloy is partly reversible under
unloading, which produces significant superelasticity. (C) 2000 Elsevier S
cience S.A. All rights reserved.