Exploring Corrosion Pathways in Wire-Arc Direct Energy Deposited Grade 2 Titanium in Chloride-Enriched Systems
摘要
Commercially pure grade 2 titanium (Cp-Ti) is important for marine and naval applications due to its excellent corrosion resistance. Additive manufacturing, especially Wire-Arc Direct Energy Deposition (WDED), enables the production of complex, large-scale Cp-Ti components but significantly alters the microstructure and properties due to thermal cycling. However, the corrosion behavior of WDED Cp-Ti in chloride-rich environments, relative to its complex microstructure, is poorly understood. This study investigates the onset and progression of corrosion in WDED Cp-Ti in HCl environments (1N-6N), revealing selective grain corrosion with evolving pitting morphology: globular at 1.25N-1.5N, pyramidal at 2N, and honeycomb-like at 6N. A novel corrosion mapping technique, combined with comprehensive electron backscatter diffraction (EBSD) analysis, reveals corrosion anisotropy within the microstructure. The grains oriented along the basal plane {0001} show superior corrosion resistance due to high in-plane atomic packing density, while prismatic planes {10