Abstract The onion-like carbon (OLC) possesses a micro-spherical structure with a diameter of approximately 7 nm consisting of 0.35 nm-spaced carbon layers, and the OLC film is capable of providing excellent solid lubrication performances because of the high content of sp2-bonded carbon phase. However, the unfavorable durability severely restricts the lubrication application in practice. For the purpose of addressing this issue, heat treatment is employed to improve the lubrication robustness of the loose OLC film. The wear resistance was significantly improved with a duration of 60000 sliding cycles at least when the OLC-coated samples were annealed at 600 °C in vacuum. Furthermore, the systematic analyses, particularly providing deep insights into the microstructural characterization, indicate that the structural reinforcement of OLC and the net-like adhering structures formed on the steel substrates annealed at specific temperature can effectively promote lubrication characteristics in two different stages. We propose that annealing treatment can improve the stability of micro-spherical OLC structures, thereby increasing the duration of lubrication. The evolution mechanism of OLC structures at the sliding interface is the key factor for maintaining the lubrication duration in dry contact.

中文翻译：

---

结构演化对滑动界面的影响，通过热退火提高洋葱状碳膜的摩擦学性能

摘要 洋葱状碳 (OLC) 具有直径约 7 nm 的微球结构，由间隔 0.35 nm 的碳层组成，并且 OLC 膜由于 sp2 含量高而能够提供优异的固体润滑性能。 - 键合碳相。然而，不利的耐久性严重限制了实际润滑应用。为了解决这个问题，采用热处理来提高松散的 OLC 膜的润滑强度。至少当 OLC 涂层样品在 600°C 真空中退火时，耐磨性显着提高，持续时间为 60000 次滑动循环。此外，系统分析，特别是提供对微观结构特征的深入见解，表明OLC的结构增强和在特定温度退火的钢基体上形成的网状粘附结构可以有效地促进两个不同阶段的润滑特性。我们建议退火处理可以提高微球 OLC 结构的稳定性，从而增加润滑的持续时间。滑动界面处OLC结构的演化机制是维持干接触润滑持续时间的关键因素。