Hetero-shaped honeycomb arrays with Ag/GO/MoO₃ towards adaptive lubrication in a wide temperature range

Structural lubricity is an emerging and significant phenomenon in modern tribology, which is expected to greatly diminish friction. Notably, it is urgent to minimize friction under extreme conditions such as ultra-high temperature to improve the accuracy and service life of mechanical assemblies. Herein, inspired by the structural optimization phenomenon of honeycomb adapting to the environment, several hetero-shaped honeycomb structural SiOC ceramics were developed through 3D printing technique. Their corresponding synergistic lubrication performance with Ag/GO/MoO₃ ternary lubricants under different temperatures were investigated. Compared with the printed structure-less SiOC, the friction coefficients of all hetero-shaped honeycomb structural samples were reduced by more than 35%. The “Cross” structural composite achieved an excellent lubrication state with friction coefficient of 0.134 at 25°C, and “Trefoil” structured composite exhibited a stable friction coefficient of 0.365 at 800°C. This can be credited with the well-designed structure that deposits lubricants efficiently and collects wear debris in large quantities. Moreover, the combination of micro rolling effect of Ag/GO/MoO₃ at room temperature with the adaptive layered Ag₂MoO₄ at high temperature enables excellent lubrication in a wide temperature range. This work sheds new light on the future development of lubrication systems and structural friction elements for extreme environments.