Abstract
Plasma spraying is the most versatile coating process for depositing a wide range of materials to enhance material performance in harsh conditions. However, severe oxidation during the plasma spraying of metal coatings often results in coatings with high oxide content, limiting interlamellar bonding. Consequently, as-sprayed metal coatings offer inadequate protection against severe corrosion and wear. To address this challenge, we developed Ni-, Cu-, and Fe-based materials containing boron as a deoxidizer. This innovative approach effectively suppresses in-flight oxidation, producing oxide-free molten droplets and enabling the formation of bulk-like metal coatings with sufficient metallurgical bonding between splats. We employed a modified tensile test to evaluate the adhesive and cohesive strengths of these coatings. The Ni-based coatings exhibited adhesive strength exceeding 150 MPa on Fe-based substrates, while cohesive strength surpassed 260 MPa with a novel bond coat. Corrosion and gas penetration tests confirmed the creation of dense, bulk-like Ni-based alloy coatings, demonstrating their potential for various applications in severe service environments.
