Effect of Cr content on micro-galvanic dissolution behavior and corrosion characteristics of Cu-Cr alloy laser cladding layer in a simulated seawater environment

Marine biofouling is a key issue that deteriorates the service performance and lifespan of ships and underwater engineering structures. The development of effective and long-term antifouling coating material is significant but still poses a great challenge. Herein, we have proposed the Cu-Cr cladding layers containing submicron Cr-rich precipitated phases were prepared via laser cladding technology. The cladding layers were aimed to ensure the continuous release of copper ions through the micro-galvanic cells by promoting Cu2(OH)3Cl flaking, and thus achieve effective and long-term antifouling performance. The effect of Cr content on corrosion behavior and antifouling performance of Cu-Cr cladding layers in a simulated seawater environment was investigated. The results demonstrated that corrosion and copper ions release rates increased while the P. tricornutum coverage rate decreased with the increase in the Cr content. It was associated with the increase of Cr-rich precipitates accelerating the corrosion of Cu-rich matrix within micro-galvanic cells. Importantly, the increased accumulation of Cr2O3-rich particles intensified the loose and cracked Cu2(OH)3Cl flaking, ensuring the long-term continuous release of copper ions from the cladding layer and thus achieving effective antifouling performance.