Abstract:

The lubrication performance of grease is prone to deteriorate under high temperature and high load conditions, leading to severe friction and wear. Two-dimensional nanomaterials are widely used as lubricant additives due to their excellent friction-reducing and anti-wear properties, which can significantly improve the tribological performance of lubricating grease. However, their enhancement effect on lubricants is often reduced due to agglomeration. Graphene oxide/magnesium hydroxide [GO-Mg(OH)₂, GM] composite material was prepared by the oxidation-reduction method. Silicon coupling agent was used as a modifier to modify the GM particles by high-energy ball milling, resulting in modified graphene oxide/magnesium hydroxide [KH-GO-Mg(OH)₂, KGM]. The performance of GM and KGM lubrication under high temperature and high load conditions was investigated using a SRV-4 friction and wear tester, and various characterization methods were used to analyze the two materials and the test wear scars. Research analysis showed that KGM had smaller size and thickness than GM. Both GM and KGM, as lubricant additives, could improve the tribological capability of the base grease with the optimal mass fraction being 0.5%. lubrication effect and friction-reducing and anti-wear performance of KGM were more prominent. Under high temperature (150℃) and high load (3.5GPa) conditions, the friction coefficient and wear width were reduced by 36.5% and 33.7%, respectively. KGM formed a lubricating protective film containing iron, magnesium, silicon and oxygen elements through adsorption on the friction surface, which exhibited friction-reducing, anti-wear effects and repair functions. This provided a simple and economical reference for the development of efficient lubricating greases under harsh conditions, holding significant potential and research value in sustainable lubrication.

Key words: graphene oxide, magnesium hydroxide, composites, lubricant additives, friction and wear

摘要：

润滑脂在高温高载工况下润滑性能易发生恶化，从而导致严重的摩擦磨损，二维纳米材料因具备优异的减摩性能，能够显著改善润滑脂的摩擦学性能而广泛用作为润滑添加剂，但其往往会因团聚效应而降低其对润滑剂的增强效果。通过氧化还原法制备出氧化石墨烯/氢氧化镁[GO-Mg(OH)₂，GM]复合材料，以硅烷偶联剂为改性剂，利用高能球磨法对GM颗粒进行改性制备出改性氧化石墨烯/氢氧化镁[KH-GO-Mg(OH)₂，KGM]，使用SRV-4摩擦磨损试验机考察了GM、KGM对基础脂高温高载荷下润滑性能的影响，采用多种表征手段对两种材料和磨痕进行表征分析。研究分析表明：KGM较GM具有更小尺寸和厚度；GM和KGM两种润滑添加剂均能提升基础脂的摩擦学性能，最佳质量分数均为0.5%，且KGM的润滑效果和减摩抗磨性能更加突出，在高温（150℃）和高载荷（3.5GPa）下摩擦系数和磨损宽度分别降低36.5%和33.7%。KGM在摩擦表面通过吸附作用形成含有铁、镁、硅和氧元素的润滑保护膜，具有减摩抗磨效果和修复作用。这为研究开发苛刻工况下的高效润滑脂提供了简易、经济的制备方法参考，在可持续润滑方面具有重要潜力与研究价值。

关键词: 氧化石墨烯, 氢氧化镁, 复合材料, 润滑添加剂, 摩擦磨损