Investigation of high temperature phase structures ofmagnetic Co-Ni-Al-Si alloys with shape recall

In this study, the physical properties between Co-Ni-Al-Si-Sb and Co-Ni-Al-Si-Mo shape memory alloys, which have recently attracted attention due to their technological applications, were compared after being produced in an induction melting furnace. Differential Scanning Calorimeter (DSC) measurements for determination of high temperature phase structures of Co-Ni-Al-Si-Sb and Co-Ni-Al-Si-Mo shape memory alloys; X-Ray Diffraction for determination of mesh distances; Scanning Electron Microscopy (SEM) and optical microscopy experiments were performed to examine the metallographic structures, and Vickers hardness measurements were performed for hardness changes. At the end of experimental measurements, it was observed that the addition of molybdenum and antimony caused changes in the crystal structure of the Co-Ni-Al alloy, and the addition of molybdenum reduced all austenitic and martensitic transition temperatures except the Mf temperature, which is the most important feature of shape memory alloys compared to antimony. In addition, it has been determined by metallography studies that the microstructures of molybdenum and antimony-added Co-Ni-Al alloys contain some changes when compared with each other, and the presence of phases determined by X-ray analysis. It has been understood that the hardness of molybdenum-added samples is generally higher in the micro hardness values of alloys. Some important changes in their magnetic properties have also been determined. It has been observed that the magnetic transition temperature increases with the addition of antimony, and a significant decrease in the magnetic saturation value has also been detected.