Study on Interface Modulation Mechanism of Cold-Sprayed Micro-/Nano-MoS₂/Cu Self-lubricating Anti-Wear Composite Coating

The lifespan of plunger pumps is often limited by wear at the distributor plate and copper-pad rotor interface. Molybdenum disulfide (MoS₂) is renowned for its exceptional solid lubrication properties. This study employed a high-energy ball milling method to prepare micro-/nano-MoS₂ composite powder, which was then used to fabricate Cu/MoS₂ composite coatings (with an Al bond layer) via the cold spraying (CS) process. Results indicate that at 900 °C spraying temperature, a vortex-dominated microstructure formed at the Cu-Al interface. The average friction coefficient decreased from 0.77 (unlubricated coating) to 0.09 (sprayed lubricated coating). The reduction in friction coefficient and wear rate was primarily attributed to the boundary lubrication effect of the MoS₂ surface layer in the composite coating. By lowering shear forces during friction, excellent anti-friction and wear-resistant properties were achieved. The optimized cold spraying processing window identified in this study provides valuable guidance for manufacturing wear-resistant coatings for critical pump friction components.