High-temperature solid lubricants play a significant role in the hot metal forming process. However, preparing high-temperature solid lubricant is formidably challenging due to the stern working conditions. Here we successfully develop a new type of eco-friendly high-temperature graphite-based solid lubricant by using amorphous silica dioxide, aluminum dihydrogen phosphate, and solid lubricant graphite. The solid lubricating coating exhibits excellent tribological properties with a very low friction coefficient and good wear protection for workpiece at high temperature under the air atmosphere. An array of analytical techniques reveals the existence of solid lubricant graphite in the lubricating coating after the high-temperature friction test. A synergistic effect between the protective surface film and the solid lubricant graphite is proposed to account for such superior lubricating performance. This work highlights the synergistic effect between the protection layer and the lubricant graphite and further provides the insight in designing the high-temperature solid lubricant.

高温固体润滑剂在热金属成型过程中发挥着重要作用。然而，由于恶劣的工作条件，制备高温固体润滑剂极具挑战性。在这里，我们利用无定形二氧化硅、磷酸二氢铝和固体润滑剂石墨成功开发出一种新型环保型高温石墨基固体润滑剂。固体润滑涂层表现出优异的摩擦学性能，具有极低的摩擦系数，在空气气氛下的高温下对工件具有良好的磨损保护。一系列分析技术揭示了高温摩擦试验后润滑涂层中存在固体润滑石墨。提出保护表面膜和固体润滑剂石墨之间的协同效应来解释这种优异的润滑性能。这项工作突出了保护层和润滑剂石墨之间的协同作用，并进一步为设计高温固体润滑剂提供了见解。