Tribological behavior and mechanism of high-temperature self-lubricating wear-resistant composite coatings on 3D-printed SiC ceramic surfaces

Abstract

In this paper, high-temperature self-lubricating wear-resistant YSZ-Al₂O₃-CaF₂-C composite coatings were prepared on the surface of 3D-printed SiC ceramics using nano-ZrO₂ modification assisted with plasma spraying technology. This study focuses on the tribological behavior and mechanism of the composite coatings between room temperature and 600 °C. From room temperature to 600 °C, the composite coatings' friction coefficients and volumetric wear rates fell between 0.151 and 0.496 and 0.91 × 10⁻⁵ and 5.58 × 10⁻⁵ mm³ /N·m, respectively. During friction, the self-lubricating effect of C at room temperature and CaF₂ at high temperature (above 400 °C) can produce a lubricating film and effectively reduce the friction coefficient of the composite coatings. Microscopic analysis revealed that the primary wear characteristics of the composite coatings are abrasive chips, grooves, and Si transfer layers, demonstrating that the wear mechanisms are abrasive wear and adhesive wear. It indicates that the high-temperature self-lubricating and wear-resistant performance of the YSZ-Al₂O₃-CaF₂-C composite coatings can be significantly improved by designing the material components, which is of great significance for the application of wear-resistant ceramic parts in aerospace industry.