Laser-based fabrication of superwetting titanium alloy with enhanced corrosion and erosion-corrosion resistance

Abstract

Titanium (Ti) alloy is vulnerable to erosion and corrosion effect of sea water in the application of marine equipment and prone to degradation and failure. In order to further enhance the erosion-corrosion resistance of Ti alloy, a laser-heat hybrid treatment is applied to fabricate superwetting Ti alloy surface. The surface morphology, chemical composition and surface wettability of Ti alloy before and after laser processing are characterized. The surface behaviors of the superwetting Ti alloy surface during corrosion and erosion-corrosion interaction are evaluated by electrochemical station and two-phase flow erosion equipment. The experimental results indicate that the periodic micro-bump structure induced by laser texturing and the low surface energy after heat treatment contribute to the surface wettability transformation into superhydrophobicity with the contact angle of 156.2°. Compared with the untreated Ti alloy surface, the laser-heat-treated superhydrophobic surface exhibits a smaller corrosion current density and a larger potential in NaCl solution, showing better corrosion resistance. The surface erosion-corrosion resistance has also been increased by 18% due to the decrease of solid-liquid contact area caused by air cavity of superhydrophobic surface. This can provide a solid laser-based fabrication method of Ti alloy for long-term and stable application in marine environment.