Sliding wear mechanisms and speed-load wear map of cylinder liner and piston ring under lubricated conditions

This study investigated the wear behavior of cylinder liners and piston rings under various speed-load conditions through systematic wear tests. The wear mechanism of the cylinder liner under different parameter combinations was analyzed using a scanning electron microscope (SEM), X-ray energy dispersive spectrometer (EDS), and transmission electron microscope (TEM). The cylinder liner was categorized into various wear states based on wear rate and the evolution of wear mechanisms. A speed-load wear map of the cylinder liner was developed using the partition fitting method. The results demonstrate that the tribofilm on the cylinder liner plays a significant anti-wear role in the mild wear state, reducing the wear rate of the substrate material. The transition from mild to severe wear involves an intermediate stage where cracks form independently. Severe wear conditions are primarily characterized by delamination wear. Furthermore, lubricating oil that infiltrates the crack gaps forms a tribofilm, accelerating the propagation of fatigue cracks and the generation of debris.