Comparison of thermal and structural properties of TiNiNb, TiNiTa, TiNiZr shape memory alloys

Shape memory alloys (SMA) have received a lot of attention in recent years as they have the ability to regain their original shape after deformation. Among these alloys, TiNi-based shape memory alloys are also widely used in academic and industrial fields due to their properties such as high strength, biocompatibility, and corrosion resistance. However, the inclusion of other elements in TiNi alloys affects the thermal, mechanical, and biocompatibility properties of the alloys, and this may increase the performance of the alloys in some areas of use. In this thesis, biocompatible TiNiX alloys of TiNi-based SMAs were produced using Nb, Zr, and Ta. These alloys were investigated and compared in terms of their thermal properties and surface morphologies. One of the aims of this study is to positively increase the effects of Nb, Zr, and Ta on the functional and biocompatibility properties of TiNi-based SMAs, which have been extensively studied on biocompatibility in previous studies. In other words, developing new TiNi-based SMAs with specific properties for various applications such as biomedical devices, actuators, and sensors constitute the research area of this study. In short, it is aimed to obtain new information about the properties of TiNiX SMAs by using advanced experimental techniques in this research. Thermal properties, atomic sizes, and crystal structures of materials are the most important parameters in forming alloys. Because these parameters are different, different substances can show properties that they cannot show alone when they come together. For example, TiNi alloy has shape memory ability under suitable conditions. While Ti and Ni metals do not have shape memory abilities on their own in nature, they show shape memory effect (SME) when combined. In the study, it was investigated by preserving the shape memory effect of TiNi alloy, reducing the ratio of toxic Ni metal, and adding biocompatible X metals in order to contribute to the production of biocompatible alloys with SME. In this way, it is aimed to minimize the possibility of allergic effects in living organisms by reducing the ratio of the toxic metal Ni, thus facilitating the use of the obtained alloys in living organisms without losing their shape memory feature and preserving their biocompatibility. In this study, the results of thermal conductivity, thermal capacity, similarities, and differences in crystal structures were observed.