Origins of the wear resistance of AlSi cylinder bore surfaces studies by surface analytical tools

This paper investigates the origin of the wear resistance of hypereutectic AlSi cylinder bore surfaces using atomic force microscopy, auger electron spectroscopy and focused ion beam analysis. Our findings suggest that the piston ring is not sliding on top of the raised silicon primary crystals, as often assumed. Instead, a new surface material is formed during running-in, which is sintered by wear particles as a result of the energy dissipated during sliding. The process can be understood as a friction induced particle strengthening of the aluminium matrix which raises the shear strength of the original material. Eventually this surface provides the wear resistance of the cylinder bore.