In today’s world, where technological progress requires high efficiency and durability of mechanisms, the development of innovative lubricants is becoming critically important. Liquid metal lubricants, due to their unique properties, such as high thermal conductivity and low friction, are a promising direction in this area.
This paper is devoted to the investigation of a new gallium-based liquid metal lubricant modified by adding copper. Gallium, which has a low melting point, is an excellent base for liquid metal lubricant, but its lubricating properties can be improved.
Gallium-based liquid metals are considered as promising heat transfer fluids and lubricants for various industries. In this work, copper is used as an alloying element to improve the lubricating properties of Ga-In-Sn. The introduction of copper promotes the formation of CuGa2 phases. GC0.2 and GC0.5 (Ga-In-Sn with 2 and 5 wt.% Cu) demonstrate improved lubricating properties compared to Ga-In-Sn at 25 °C and 150 °C. At 150 °C, the wear of T91 steel with GC0.2 lubrication is reduced by 72.95% compared to Ga-In-Sn. At 300 °C, GC0.2 retains comparable lubricating properties with Ga-In-Sn. The lubrication mechanism is explained by a change in the characteristics of the lubricant and the formation of a lubricating film.
Modification of gallium with copper allows to increase its load-bearing capacity and reduce wear of contacting surfaces. Copper, as is known, has good antifriction properties and the ability to form protective layers on the friction surface.
During the research, tribological tests of the developed lubricant were conducted, which showed a significant reduction in the coefficient of friction and wear compared to pure gallium. Analysis of the friction surface using scanning electron microscopy confirmed the formation of a protective layer containing copper.
The obtained results indicate the potential of using gallium-modified copper as a highly efficient lubricant for various applications, including micro- and nanomechanical systems.
Author: Haixi Zhang, Yuan Yu, Guohua Zhang, Tiewei Xu, Tongyang Li, Lujie Wang, Zhuhui Qiao, Weimin Liu, Hailong Cui
Institute: School of Mechanical and Automobile Engineering, Qingdao University of Technology, Qingdao 266525, P.R. China, State Key Laboratory of Solid Lubricants, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, P.R. China, Yantai Zhongke Research Institute of Advanced Materials and Green Chemical Engineering, Yantai 264006, P.R. China, Shandong Key Laboratory of Advanced Materials and Green Manufacturing Yantai, Yantai 264006, P.R. China, Precision and Ultra-Precision Machining Technology Center, Sichuan 610200, P.R. China, Qingdao Center for Resource Chemistry and New Materials, Qingdao 266000, P.R. China