Processing, Microstructure and Properties Correlation of Nitinol
In the era of smart materials, nitinol has been broadly studied, focusing on both the basic and technological aspects. Nitinol has been gaining importance over the last two decades in different biomedical applications due to its excellent properties such as high corrosion resistance, proper biocompatibility, superior mechanical properties, and particular functional features like shape memory effect and super elasticity. The present work focuses on the preparation of nitinol through vacuum arc melting from the pre-compacted powder mixtures of 50at%Nickel-50at%Titanium. Interatomic phase formation was determined by X-Ray diffraction. Microstructural characterization were conducted under optical microscope and field emission scanning electron microscope equipped with energy dispersive spectroscopy (EDS). Also, hardness tests were performed using Vickers indentation technique. XRD analysis shows peaks of NiTias the major constituent phase along with Ni3Ti and Ni4Ti3as minor constituents. The microstructure of nitinol exhibits uniform distribution of phases indicating vacuum arc melting provides necessary alloying of powder mixture. The hardness of the processed nitinol is observed to be 576 Hv.
Keywords - Nitinol; Vacuum arc Melting; X-ray Diffraction; Microstructure; Hardness.