Corrosion behaviours of a LaB6/TiC/TiB/ti composite in neutral or acidic electrolytes

Abstract

LaB6/TiC/TiB was incorporated into a Ti–Al–Zr–Sn alloy to achieve an efficient improvement in acid-resistance. The incorporation of LaB6/TiC/TiB deteriorated the performance of the passive layer, but impeded the penetration of the corrosive medium into Ti matrix. The incorporation of the conductive reinforcements promoted galvanic corrosion, leading to a decrease in barrier effect of the passive film. Delayed passivation in less aggressive media was achieved by controlling the formation and growth of corrosion pits. The distribution of LaB6/TiC/TiB determined the corrosion properties after complete failure of the passive layer. An appropriate approach for enhancing the acid-resistance of Ti-based materials was suggested.

Keywords

• Acidic resistance
• Galvanic corrosion
• Delayed passivation
• Barrier property
• EIS