In Situ Tensile Experiments on FeMnSi Shape Memory Alloys: Texture, Microstructure and Domain Size Characterization by Synchrotron Radiation

R. BOLMARO, A.V. DRUKER, J. MALARRIA, Z.-Y. ZHONG, H.-G. BROKMEIER

Dresden

Conferencia; 17th International Conference on Textures of Materials (ICOTOM); 2014

Fe-Mn-Si based Shape Memory Alloys show deformation induced phase transformations difficult to analyze, regarding volume fraction and texture components as well as variant composition and microstructure development. Usual experimental methods can, at the most, partially evaluate those magnitudes, and their relationships with mechanical properties, on pre- and post-thermomechanical treatments. Surface and sub-surface microstructural modifications, due to sample polishing and preparation, can also hide or disguise bulk structural evolution.Synchrotron radiation is very advantageous as a characterization tool in many aspects. First, it allows an in-situ study, while the experiment progress, at increasing loading-unloading stages. Second, their high penetration power allows bulk measurements making the surface effects negligible. As a drawback, synchrotron data are somehow over abundant and of laborious interpretation and analysis.We present results on tensile tests performed on site on GEMS line at Petra III, DESY, Germany. The tensile machine was mounted directly on the beam line and Debye-Scherrer image plates were taken at every loading stage (MAR3450, 3450 x 3450, 100μm x 100μm pixels. On each loading stage a complete set of measurements were taken to calculate textures and to study phase volume fraction and microstructure evolution. After unloading a single shot was taken to follow main unloading effects. The results were analyzed by using MAUD software, by which phase volume fractions, textures and microstructure evolution could be extracted.