Tribological behavior of layered double hydroxides with various chemical compositions and morphologies as grease additives
Tribological behavior of layered double hydroxides with various chemical compositions and morphologies as grease additives
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不同化学成分和形貌的层状双氢氧化物作为润滑脂添加剂的摩擦学行为
DOI：
10.1007/s40544-020-0380-5
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发表时间：
2020-05-20
期刊：
影响因子：
6.8
通讯作者：
Luo, Jianbin
中科院分区：
文献类型：
--
作者：
Wang, Hongdong;Wang, Yue;Luo, Jianbin
层状双氢氧化物（LDH）是一种天然矿物，也可以人工制备。由于其独特的晶体结构和组成、尺寸、形貌的多样性，在各个领域得到了实际应用。本工作通过控制反应条件，成功制备了具有不同化学组成（Co2+、Mg 2+、Zn 2+和Ni 2+）和形貌特征（花状、球形和板状）的LDHs。然后，将它们机械分散到基础润滑脂中，并通过球盘试验机在2.47 GPa的接触压力下评价它们的摩擦学性能。结果表明，表面形貌的变化对摩擦学性能的影响较大，而化学成分的变化对摩擦学性能的影响较小。具有高比表面积（139 m2/g）的“花状”LDH样品被证明显示出最佳性能。当添加量为1%时，磨损量仅为基础脂的0.2%左右。LDH添加剂与滑动固体表面发生摩擦化学反应，形成具有独特微观结构和均匀成分的摩擦膜，有效地改善了润滑系统的摩擦学性能。该研究为润滑油添加剂的优化提供了指导，具有很大的应用潜力。
The layered double hydroxide (LDH) is a kind of natural mineral, which can also be manually prepared. It has been practically applied in various fields due to its unique crystal structure and diversity of composition, size, and morphology. In this work, LDHs with different chemical compositions (Co2+, Mg2+, Zn2+, and Ni2+) and topographical features (flower-like, spherical, and plate-like) were successfully prepared by controlling the reaction conditions. Then, they were mechanically dispersed into base grease and their tribological properties were evaluated by a ball-on-disk tester under a contact pressure of 2.47 GPa. It was found that the variation of morphology, instead of chemical composition, had great influence on the tribological performance. The “flower-like” LDH sample with high specific surface area (139 m2/g) was demonstrated to show the best performance. With 1 wt% additive, the wear volume was only about 0.2% of that lubricated by base grease. The tribofilm with unique microscopic structure and uniform composition was derived from tribochemical reaction between LDH additives and sliding solid surfaces, effectively improving tribological properties of the lubrication system. This work provided the guidance for optimizing lubricant additives and held great potential in future applications.