Autori: M. G. SURU, A. L. PARASCHIV, B. PRICOP, L. G. BUJOREANU
Editorial: OPTOELECTRONICS AND ADVANCED MATERIALS – RAPID COMMUNICATIONS, 7(1-2), p.141-144, 2013.
The paper reports the effects of 100 to 500 training cycles applied to lamellar specimens of a Cu-Zn-Al Shape Memory Alloy (SMA). The training procedure consisted in the bending, during the cooling to room temperature (RT) of martensitic specimens, by the load fastened at their free end and in load lifting by Shape Memory Effect (SME) during heating up to austenitic domain. During cooling, the concave surface of bent specimens was compressed and during heating it was elongated, being subjected to tension-compression cycling, during heating-cooling, respectively. Conversely, the convex surface of bent specimens was elongated during cooling and compressed during heating, being subjected to compression-tension during heating-cooling, respectively. Considering the different loading regime of the convex and concave regions, specimens were trained under various numbers of cycles and were correspondingly prepared for analysis performed by means of atomic force microscopy (AFM). The recorded 2D and 3D micrographs were corroborated with statistical evaluations of thermomechanical loading in order to emphasize the effects of both the number of training cycles and the initial loading state (tension or compression) of the specimens on the morphology of martensite plates.
Cuvinte cheie: Cu-Zn-Al shape memory alloys, Training, Thermomechanical loading, Martensite; morphology