Original scientific paper

Behaviour of thermo-mechanically treated CuZnAl-SMA

Danko Ćorić orcid.org/0000-0002-9564-8680 ; Faculty of Mechanical Engineering and Naval Architecture, University of Zagreb, Ivana Lučića 5, 10000 Zagreb, Croatia
Mladen Franz ; Faculty of Mechanical Engineering and Naval Architecture, University of Zagreb, Ivana Lučića 5, 10000 Zagreb, Croatia

Abstract

Hot rolling of CuZn27Al4 shape memory alloy results in the forming of defects in austenitic crystals. The defects such as dislocation and deformed boundaries of austenitic grains affect both "classical" material properties and the specific properties related to shape memory. Rolled and quenched alloy (ausforming treatment) shows hardening proportional to the value of introduced deformation. By increasing the level of true plastic deformation not only the yield stress and tensile strength are increased but also the pseudo yield stress thus making the mechanically induced martensitic transformation more difficult. Besides, the ausforming treatment reduces all the transformation temperatures of the austenitic-martensitic reaction, thus expanding the temperature field of pseudo-elasticity. In spite of the hardening, the thermo-mechanically treated CuZn27Al4 alloy retains the pseudo-elastic shape memory so that favourable combination of strength and transformation behaviour can be achieved by the ausforming treatment, which is required in the majority of applications of these alloys.

Keywords

ausforming treatment; CuZnAl alloy; mechanical properties; shape memory; transformation temperatures

Hrčak ID:

86734

URI

https://hrcak.srce.hr/86734

Publication date:

19.9.2012.

Article data in other languages: croatian

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