Abrasive wear mechanisms of gray cast iron application to cylinder bore abrasion

A significant part of the friction losses in the automotive engine results from the abrasive action of particles formed in the interface between cylinder and piston/rings.Those particles are responsible for axial grooves that are observed in the liners of used engines.The objective of this work was to get a better understanding of the wear mechanisms related to liner/bore grooving and to identify a laboratory testing setup that might reproduce them under controlled conditions.Specimens of Gray Cast Iron (GCI) and of AISI 1070 steel with matrix hardness close to that found in GCI (≈200HV 30 ) were submitted to scratch tests in a tribometer.It was found that scratches performed under 20-50 mN indenter load were similar to grooves observed in cylinder liners.No sharp transition between abrasion mechanisms was observed.Calculation of material removal factor f ab from optical profilometry resulted in values with a large dispersion; they could not be associated with different abrasion mechanisms.