The nanoporous structure of oil-impregnated porous copper is closely related to its tribological and oil-retention properties, which are essential for its anti-friction and anti-wear, and long-lasting lubrication. In this study, different component Cu-Al precursors were obtained via plasma-activated sintering, followed by a dealloying method to obtain bulk nanoporous copper with different porosities. The effect of the nanoporous structure on oil-retention capacity and tribological properties was investigated. The results showed that as the porosity increased from 47.48% to 67.69%, the oil content increased from 8.01% to 20.18%, while the oil-retention capacity decreased from 97.12% to 33.92% at 7000 r/min centrifugal speed. With the storage of oil, the average friction coefficient was reduced by 68.2–85.9%. The self-lubricating effect can be ascribed to an oil film formed on the surface, and the main wear forms were abrasive wear and fatigue wear. This study may provide guidance for the development of high-performance oil-impregnated lubricating nanoporous copper.
