Scuffing resistance of coated piston skirts run against cylinder bores

The results indicate that scuffing resistance of different aluminum alloy cylinder bore and piston skirt combinations varies significantly. The eutectic Al-Si alloy with high percentages of alloying elements has better scuffing resistance than the hypereutectic Al-Si alloys. The scuffing resistance is also affected by casting porosity on the bore surface. Ni-P-BN plated and iron plated pistons perform very well with aluminum bores. Surface contact, mechanical and chemical properties of bore materials, piston skirt surface textures and coatings are the major factors affecting the scuffing resistance.