Brief description of an education of an object in a shape memory alloy, which makes it possible to ensure the precision and stability of the memory effect is reversible.

摘要

Process for the education of an article made of alloy with martensite transformation with shape memory, making it possible to obtain the precision and the stability of the reversible memory effect, the said article having been put in its initial shape by starting with an alloy blank and then homogenised in beta phase. The said article is subjected repeatedly to a succession of education cycles during which: - an increasing mechanical stress sigma is applied to it at a constant temperature T1 which is higher than the transformation point Af, resulting in a deformation epsilon max in the superelastic region up to a maximum value sigma max, which is lower than the elastic limit of the material in the austenitic state at the temperature T1, - the stress sigma is released as far as a zero value, the article recovering appreciably its initial shape apart from a small residual deformation epsilon rho 1 (T1), - the placing under stress sigma max is repeated, followed by a return to zero value, the article recovering substantially its initial shape apart from a residual deformation epsilon rho 2(T1) epsilon rho 1(T1), - the placing under stress sigma max is thus repeated, followed by a return to zero value during n cycles, at least until the residual deformation epsilon rho n(T1) reaches a limiting value, -the article is then heated to a temperature T2 which is at least 50 DEG C higher than Af. IMAGE