Effect of TiB Addition on Corrosion Behavior of Titanium Composites under Neutral Chloride Solution

In this work, the corrosion behavior of titanium composites of titanium-titanium boride composites for marine applications was investigated by conducting electrochemical polarization experiments in neutral chloride (3.5% NaCl) at room temperature. The composites with two different volume fractions (20% and 40%) of TiB were processed by three powder metallurgical techniques such as spark plasma sintering, hot isostatic pressing and vacuum sintering. Corrosion rate for all the processed composites was calculated from corrosion current density determined by extrapolation of Tafel curves. Further, electrochemical impedance spectroscopy analysis was also carried out for the composites. The results revealed that the composite with 38.3 vol% titanium boride processed by hot isostatic pressing exhibited improved corrosion resistance in neutral chloride solution compared to the other two techniques. Microstructure of the corroded composites showed the pit formation in the exposed surface.