In-vitro corrosion resistance study of hot worked Ti-6Al-7Nb alloy in a isotonic medium

This investigation reports the results of linear polarization of ho' upset Ti-6Al-7Nb bar samples. Current-potential curves recorded in Hank's solutio n were analyzed by correlating characteristics of passivation and microstru ctures obtained after processing. Results have shown;that it is important t o select temperature process and deformation rate as parameters when more n oble potential values are required. Low deformation rate facilitates the fo rmation of beta phase that is retained in the structure e at room temperatu re shifting the corrosion potential to more positive values. However, sampl es hot compressed from 750 degreesC to 1030 degreesC showed passive layer s tability over a wide range of potentials extending from -0.15 V to 1.75 V v s SCE. Further-more, passive films grown onto the Ti-6Al-7Nb samples surfac es have shown no sign of rupture for the processing conditions selected fur this study.