Effect of spherical crown texturing and ionized sulfur infiltration on the tribological performance of piston-cylinder liner

In this study, the piston-cylinder liner was treated with single glow photoionization sulfurization of a cast aluminum alloy (AlSi10Mg), and the effect of the spherical crown texture on frictional properties of the piston-cylinder liner were investigated before and after the sulfurization treatment. The treated specimens were characterized and evaluated via microscopic morphological analysis, three-dimensional morphological analysis, X-ray diffraction (XRD), thin film diffraction, microhardness testing, and friction wear experiments. Fluent fluid analysis software was used to develop a flow field simulation model for the spherical crown texture. Results of the study showed that the average friction coefficients of the specimens treated with sulfur infiltration were all lower than those of untreated specimens, and the low friction coefficients were closely related to the laminar structure and weak interfacial bonding of the sulfur infiltration layer. The spherical crown structure effectively affected the stree distribution on surface of the specimens uniformly, which improved the bearing capacity and durability of the specimens, and the surface texture helped reduce the contact area and store the debris generated during the wear process, thus improving the friction performance. Mechanical stamping caused material aggregation on the edges of the weave, which increased the hardness of the edges and thus reduces the increase in wear around the weave. The surface microstructure of the specimens was effectively improved after sulfurization treatment, leading to higher wear resistance for the sulfurized specimens. Given the relative lack of research on the composite ionic sulfurization of piston-cylinder liner spherical crown texture at home and abroad, this experiment provides data support for this direction. The results provide beneficial clues for the design and optimization of the piston-cylinder liner spherical crown structure.