INFLUENCE OF ZIRCONIUM ON CORROSION RESISTANCE AND MARTENSITIC TRANSFORMATION OF TI50NI49,5FE0,2MO0,3

• Main Author: Fitri Azalia, Disha
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/69156
• Institution: Institut Teknologi Bandung

According to the World Health Organization (WHO), Coronary Heart Disease is the number one cause of death globally. One of the most reliable methods of treating coronary heart disease is by using a self-expandable stent. The alloy that is ommonly used and has good biocompatibility is the Nitinol alloy (TiNi/NiTi). Even though this alloy has been widely used as stent material, there are still many aspects that need to be developed. In some cases, the release of Ni 2+ ions are still very common considering the nickel content is quite high in the alloy, which potentially causes allergic reactions in patients. Thus, further research is needed to improve the performance, corrosion resistance, but still maintain the biocompatibility of the alloy. This study will review the effect of adding Zr on the corrosion rate and martensitic transformation behaviour Shape Memory Alloy Ti50 Ni49.5 Fe0.2 Mo0.3 (TN-10). A series of experiments were conducted to study the effect of adding Zr on the corrosion resistance and martensitic transformation behaviour of the TN-10 alloy. The research began with melting the alloying elements in the form of titanium sponge (99.5%), high purity nickel ingot (99.7%), iron chip (99.98%), molybdenum pieces (99.5%), and zirconium sponge foam (99.9%) using Mini DC Electric Arc Furnace and followed by homogenization using horizontal tube furnace in an inert environment. The resulting alloy was tested for corrosion using a potentiostat in Ringer’s Lactate solution. Furthermore, the alloys were characterized using Energy Dispersive Spectroscopy, X-Ray Fluorescence, X-Ray Diffraction, and Differential Scanning Calorimetry. From previous researches, the addition of Zr has been shown to increase the corrosion resistance of the TN-10 alloy. The best corrosion resistance was obtained by adding 0.7 at% to the alloy, which was 0.12008MW.cm2. The corrosion rate also decreased along with the increasing of Zr in the alloy. The lowest corrosion rate was 0,00365435 mm/year in the alloy with the addition of 0.7 % Zr. In addition, the results of the measurement of the alloy transformation temperature showed that the addition of Zr increased the transformation temperature significantly. The highest martensitic transformation temperature was obtained by adding Zr of 0.7 at% with M s of 81.1ºC and M f of 31.16ºC.