Hydrogen-bond regulated NADES lubricants enable ultra-low wear in high-speed ball screw pairs

Ball screw pairs are susceptible to severe friction and wear under harsh operating conditions, particularly high loads and high speeds, which compromise positioning accuracy and transmission stability. To address these challenges, this study develops a novel green lubricant based on natural deep eutectic solvents (NADESs), which exhibit high load-carrying capacity and stable lubrication performance. Experimental results reveal that the dense hydrogen bond network within NADESs restricts molecular mobility, thereby enhancing film stability. A robust tribofilm is formed through the synergistic mechanism of physicochemical adsorption and tribochemical reactions, resulting in significantly smoother worn surfaces. Compared to the commercial lubricant PAO40, the proposed NADESs reduced the friction coefficient and wear volume by 32.6% and 89.1%, respectively. Furthermore, friction torque tests on ball screw pairs demonstrated that NADESs exhibit superior lubricity and significantly improved motion stability even at high rotational speeds. Consequently, the formulated NADESs show great potential as high-performance green alternatives for precision transmission systems requiring high load-bearing capacity.