Investigation of Thermal properties, Chemical Analysis and Biocompatibility of High Temperature Oxidized NiTiMn Shape Memory Alloy

Abstract

In recent years, studies have been conducted on the biocompatibility of NiTi-based shape-memory alloys, which are used in medical application. In this study, the oxidation process of Ni48Ti51Mn alloy produced with Arc Melter Method with the Thermogravimetric Analysis Device (TG/DTA) was performed to improve biocompatibility for three different oxidation temperatures (600-700-800oC). The oxidation rate of the alloy that was exposed to isothermal oxidation was calculated. With the increase in the oxidation temperature, the alloys were oxidized faster. The change of the oxidation on the Shape-Memory Effect (SME) of the NiTiMn alloy was determined by Differential Scanning Calorimetry (DSC), and it was observed that the SME did not disappear. The changes occurring on the surface and on the crystal structure of the alloy were determined by SEM-EDX and X-ray analyses. It was determined with chemical analysis (EDX) that a TiO2 layer was formed on the alloy. The fact that the TiO2 layer increased with the increase in the oxidation temperature was supported with x-ray measurement results. In this way, it was concluded that there was a protective oxide layer on the surface of the alloy. ICP-MS measurements were done to determine penetration of Ni,Ti and Mn element of oxides alloys in to Ringer solution.