The lubrication conditions of friction pairs in water or aqueous solutions are crucial to the performance and lifespan of key mechanical components in engineering applications.In our previous research,a promising in s...The lubrication conditions of friction pairs in water or aqueous solutions are crucial to the performance and lifespan of key mechanical components in engineering applications.In our previous research,a promising in situ self-sensing method was proposed on the basis of liquid‒solid triboelectric signals generated from the rotation-induced streaming current.However,the understanding of the interfacial charging mechanism and the enhancement of the signal outputs from the viewpoint of the zeta potential are deficient.In addition,the influence of a convergent channel on the zeta potential needs further investigation,which fits most engineering conditions for seals or bearings because of the hydrostatic or hydrodynamic effect.Herein,electrode-coated silicon nitride(Si3N4)composites are prepared via laser machining and magnetron sputtering.The interfacial charging mechanism is proposed on the basis of a comprehensive investigation of the effects of the electrode area ratio,surface roughness,and liquid ion concentration on the zeta potential.The zeta potential originates from the combined effects of the dissolution of metallic electrodes and the hydration effect of Si3N4.The interfacial charging mechanism can be explained by the ion absorption of the ceramic substrate and the conduction behavior of the electrode layers.Moreover,samples with convergent profiles along the fluid flow exhibit a greater absolute value of the zeta potential than divergent samples do,and a negative relationship between the zeta potential and convergent slope is observed.Finally,design criteria for self-sensing friction pairs are proposed for enhancing the interfacial charging performance:an optimal electrode area ratio of 40%,a surface roughness of 0.1-0.2μm,and an aqueous solution with a moderate number of hydrated ions.Working conditions with a large variation in the film gap are preferable in terms of discernibility and sensitivity.This work builds a bridge between the interface charging mechanism and the self-sensing application of liquid‒solid triboelectric behaviors on the basis of streaming current input.展开更多
基金supported by the National Natural Science Foundation of China(No.52475201)the National Science and Technology Major Project of China,and the Tribology Science Fund of the State Key Laboratory of Tribology in Advanced Equipment with the grant number SKLT2024Z10.
文摘The lubrication conditions of friction pairs in water or aqueous solutions are crucial to the performance and lifespan of key mechanical components in engineering applications.In our previous research,a promising in situ self-sensing method was proposed on the basis of liquid‒solid triboelectric signals generated from the rotation-induced streaming current.However,the understanding of the interfacial charging mechanism and the enhancement of the signal outputs from the viewpoint of the zeta potential are deficient.In addition,the influence of a convergent channel on the zeta potential needs further investigation,which fits most engineering conditions for seals or bearings because of the hydrostatic or hydrodynamic effect.Herein,electrode-coated silicon nitride(Si3N4)composites are prepared via laser machining and magnetron sputtering.The interfacial charging mechanism is proposed on the basis of a comprehensive investigation of the effects of the electrode area ratio,surface roughness,and liquid ion concentration on the zeta potential.The zeta potential originates from the combined effects of the dissolution of metallic electrodes and the hydration effect of Si3N4.The interfacial charging mechanism can be explained by the ion absorption of the ceramic substrate and the conduction behavior of the electrode layers.Moreover,samples with convergent profiles along the fluid flow exhibit a greater absolute value of the zeta potential than divergent samples do,and a negative relationship between the zeta potential and convergent slope is observed.Finally,design criteria for self-sensing friction pairs are proposed for enhancing the interfacial charging performance:an optimal electrode area ratio of 40%,a surface roughness of 0.1-0.2μm,and an aqueous solution with a moderate number of hydrated ions.Working conditions with a large variation in the film gap are preferable in terms of discernibility and sensitivity.This work builds a bridge between the interface charging mechanism and the self-sensing application of liquid‒solid triboelectric behaviors on the basis of streaming current input.
