Production and investigation of physical properties of NiMnSnTa ferromagnetic shape memory alloys

In this study, Ni-39Mn-11Sn, Ni-39Mn-11Sn-1Ta and Ni-39Mn-11Sn-3Ta (percentage by atomic) ferromagnetic shape remembrance alloys, whose alloy ratios were given Ta0, Ta1 and Ta3 codes, respectively, were produced and their physical properties were examined. Differential scanning calorimetric (DSC) was used to determine phase transformation temperatures, thermodynamic parameters and activation energy of alloys, X-ray analysis device (XRD) for martensite phase crystal structure determination, optical microscope and SEM for surface morphology investigation. As a result of experimental studies, it has been observed that phase transformation temperatures occur at lower temperatures compared to the amount of Tantalum (Ta) element that increases in the ratio of the element Nickel (Ni) in the alloys. In scanning electron microscopy (SEM-EDX) measurements, it was observed that the prepared alloys showed a homogeneous chemical distribution and contributed to the martensite plates by forming β-Ta structures in some parts of the alloys added by reducing the Ni element. With the EDX analysis taken from the surfaces of the alloys, it was determined that the material was compatible with the produced ratios. It was determined that the alloys receiving X-rays at room temperature have a martensitic microstructure. As a result of these measurements, it has been determined that the proportions of the elements in NiMnSnTa alloys have a significant effect on the thermodynamic properties and microstructure