Tribological behavior of layered double hydroxides with various chemical compositions and morphologies as grease additives

Friction

Qiang Wang¹  Jinjin Li²  Hongdong Wang²  Jianbin Luo²  Yuhong Liu²  Jun Zhao³  Yue Wang⁴ 

[1] College of Environmental Science and Engineering, Beijing Forestry University, 100083, Beijing, China;State Key Laboratory of Tribology, Tsinghua University, 100084, Beijing, China;State Key Laboratory of Tribology, Tsinghua University, 100084, Beijing, China;College of Mechanical and Electrical Engineering, Beijing University of Chemical Technology, 100029, Beijing, China;State Key Laboratory of Tribology, Tsinghua University, 100084, Beijing, China;School of Mechanical Engineering, Guizhou University, 550025, Guiyang, China;

关键词: layered double hydroxide;    lubricant additive;    tribological property;    grease;    graphene oxide;   

DOI  :  10.1007/s40544-020-0380-5

来源: Springer

【 摘 要 】

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.

【 授权许可】

CC BY