A novel in situ laser cladding technology incorporating an underwater air chamber for the manufacturing of 316 coating

Abstract

Marine equipment faces significant maintenance challenges due to the inability to extract components from the marine environment for repair. Over the past decade, laser cladding technology has experienced rapid development as a method for repairing key parts of ships. However, the direct application of underwater laser cladding for in situ repair remains an area requiring further exploration. This study introduces the development of an innovative air chamber laser processing head and, for the first time, presents an in situ laser repair technology called Underwater Directed Energy Deposition with Air Chamber (UDED-AC). The behavior of the underwater air chamber was analyzed using the Young-Laplace equation and the Rayleigh-Plateau instability principle, elucidating its influence on the cladding process. Additionally, a comparative analysis of the morphology and properties of 316 coatings fabricated in air and underwater environments was conducted. The results indicate that using UDED-AC in situ additive manufacturing technology leads to a deeper molten pool in the underwater environment compared to air. Moreover, the increased precipitation of SiO₂ particles within the dendrites enhances the hardness of the cladding layer prepared underwater. Meanwhile, the corrosion resistance and wear resistance of the deposited layers show no significant differences between underwater and air-prepared samples. The UDED-AC technology uniquely integrates the flexibility of underwater wet cladding with the precision of local drainage cladding, offering a transformative approach for underwater in-situ repair. This innovation holds significant promise for the repair and maintenance of marine equipment in challenging environments.