Optimization of Composition Design and Analysis of the High-Temperature Tribological Behavior of a Composite Coating with an Inorganic Phosphate Matrix
摘要
In this study, an ideal inorganic phosphate (IP) matrix composite coating was successfully designed by component optimization strategy. The tribological behavior and wear mechanism of the coating were investigated from 100 to 500 °C. Proper amounts of solid lubricants greatly enhanced the hardness, adhesion, wear resistance, and roughness. Mullite fibers (MFs) increased the toughness and load-carrying capacity, which effectively stabilized the wear process. IP270MF is the optimal coating and has excellent friction–reduction properties. The friction coefficient of the coating was 0.20, which was 56.5% lower than that of the substrate. The formation of phosphate macromolecular film improved the lubrication performance and reduced the curing temperature, preventing foil damage. Nevertheless, considerable water loss at high temperatures resulted in the binder becoming embrittled, which reduced adhesion. The range of the average friction coefficient was 0.31 to 0.48 between 100 and 500 °C. The IP270MF coating had the maximum wear resistance (1.6 × 10−5mm3 N−1 m−1) and hardness (151 HV) at 200 °C. The wear mechanism was dominated by adhesive wear at low temperatures and fatigue wear at temperatures of 300 °C or higher. The soft IP270MF coating is expected to provide effective lubrication in foil bearing applications.