Effect of Surface Strengthening on Corrosion Property of Ti-6Al-4V in 3.5 NaCl

摘要

By means of Ultrasonic shot peening (USSP), a strengthening surface layer was formed on Ti-6Al-4V. The polarization curves with different treatment times were investigated in 3.5% NaCl. The type of semiconductor for passive film of 30 min treatment was measured by Mott-Schottky curve, and the thickness of the passive film was calculated. The result of the polarization curves show that the corrosion resistance of the USSP treatment samples is increased compared with the untreated sample. Mott-Schottky curve of with 30 min USSP treatment sample show that the passive film belongs to n-type semiconductor. The thickness of the passive film is much thicker than the untreated sample, and the charge carrier density is smaller than that of untreated sample. These indicate that the surface strengthening improves the corrosion resistance of the Ti-6Al-4V in 3.5% NaCl by forming stable passive film.