Microstructure and Electrochemical Behavior of in Vitro Ti-26Nb, Ti-26Zr and Ti-26Ta Alloys Processed by Levitation Melting Technique

Abstract

This paper presents a study on microstructure, elasticity modulus and electrochemical behavior of Ti-26Nb, Ti-26Zr and Ti-26Ta binary alloys obtained in an induction furnace equipped with a water cooled copper crucible which can promote levitation of the moltem alloys. The microstructures and eletrochemical behavior were investigated by means of X-ray fluorescence spectroscopy, X-ray diffractometry, optical microscopy, microvickers hardness, open circuit poten- tial, corrosion potential and polarization resistance. The results revealed that the difference in nominal chemical composi- tion related to contamination was extremely low, which indicates that this melting technique is highly appropriate for ob- taining contaminant-free titanium alloy. The addition of niobium was very favorable for obtaining near-β alloy with a low elasticity modulus. Additionally, alloy Ti-26Nb presented the best corrosion resistance combined with low elasticity modulus.