Plasma protective ceramic coating of the Al2O3–Ni system from cladded powder mixture

Abstract

To solve the problem of increasing the adhesive-cohesive strength of multifunctional plasma coatings used to protect parts of power and machine building equipment from wear and corrosion, a ceramic coating of the Al₂O₃–Ni system, obtained from a powder mixture based on corundum clad nickel. The coating was applied by the method of high-energy plasma powder spraying (on the “Thermoplasma” installation) on the intermetallic sublayer of the Ni–Co–Cr–Al–Y system. The aim of this work was to study the microstructure, phase composition, mechanical, tribological and adhesion properties of a plasma ceramic coating formed from a powder material based on aluminum oxide clad with a refractory metal component (nickel). According to the research results, it was found that the initial powder material has a multi-phase composition (Ni + α-Al₂O₃ + γAl₂O₃) and a spherical morphology of particles. From it, during high-energy plasma spraying, a coating is formed with a phase composition (Ni + γ-Al₂O₃ + γ'-Ni₃Аl), a layered microstructure with nickel interlayers and a columnar structure of oxide grains. The coating has high values of hardness and adhesive-cohesive strength, low coefficient of friction and is recommended for wear protection of parts of power engineering and mechanical engineering.