Scuffing resistance property of Al-Si alloy cylinder liner after mechanical honing shaping under starved lubrication

To enhance the scuffing resistance of Al-Si alloy cylinder liners, mechanical honing shaping was employed. Comparisons were made with untreated and chemically etched Al-Si alloy cylinder liners. The scuffing resistance properties were evaluated using a starved lubrication test method. CrN piston rings (coated via PVD) and Chrom-Keramik-Schicht (CKS) piston rings were used in the tests against the cylinder liners. A stress contact model was established based on the state of silicon particles to analyse the scuffing resistance mechanism. The results indicated that the PVD piston ring exhibited superior scuffing resistance compared to the CKS piston ring. This improvement is attributed to the numerous small holes on the surface of the PVD piston ring, which effectively store oil. The mechanically honed Al-Si alloy cylinder liner demonstrated the best scuffing resistance properties. When paired with the PVD piston ring, the friction coefficient of the mechanically honed Al-Si alloy cylinder liner decreased by 17%, and the scuffing time increased fivefold. Finite element analysis revealed that the silicon particles protruding on the surface of the mechanically honed Al-Si alloy cylinder liner had a rounded shape, resulting in lower stress during friction.