Martensitic Transformation on FeMnSi Shape Memory Alloys Investigated by In-Situ Synchrotron Radiation and by EBSD

BOLMARO, RAÚL E.; MARTINA AVALOS; ANA VELIA DRUKER; JORGE MALARRÍA; NORBERT SCHELL; ZHENGYE ZHONG; H.-G. BROKMEIER

Cancún

Congreso; XXIV International Materials Research Congress; 2015

Sociedad Mexicana de Materiales

Shape Memory Alloys (SMA) subject to plastic deformation show complex phenomena regarding martensitic phase transformation, transformed volume fraction and variant composition, simultaneously competing with slip plastic deformation and texture components. Moreover, microstructural characteristics, as grain and sub-grain sizes, dislocation arrays and stacking faults, develop along the process. We have tested FeMnSi SMA to inspect phase transformation characteristic, main texture components and microstructure development, by high penetration synchrotron radiation, taking advantage of the in-situ capabilities.Tensile tests were performed on GEMS line at Petra III, DESY, Germany, in transmission geometry at 87 KeV. A complete set of image plates were taken every 5o to characterize whole orientation dependent variables during the loading process. A single image plate was taken after unloading to follow main possible relaxation effects. Further analysis was performed by MAUD software, which allows the determination of textures, phase volume fraction and microstructure evolution. Mechanical behavior during tensile deformation is associated with the different stages of phase transformation and plastic yield. Topological and micro-textural data is unavailable by x-ray diffraction. We performed ex-situ EBSD characterization to compare both techniques and in search of local texture analysis. Texture results and phase volume fractions were found to be compatibles with the results obtained by Synchrotron radiation-MAUD analysis.