Evaluation of the Tribological Behavior and Application of Several Running-in Lubricants for Cylinder Liner-Piston Ring Pair in Internal Combustion Engine

Two running in lubricants were prepared in an attempt to prevent the cylinder liner piston ring of an internal combustion engine from scuffing and seizure. The antiwear and extreme pressure properties of the two formulated running in lubricants were compared with that of a reference commercial counterpart on a four ball machine, while the thermal stability of the lubricants examined by means of thermogravemetric analysis and differential scanning calorimetry. The surface morphology of the cylinder liner after running in tests was observed with a scanning electron microscope. As the results, the two formulated lubricants show better antiwear and extreme properties than the reference counterpart. They also have relatively good thermal stability. Moreover, the cylinder liner piston ring pair has good surface quality after running in with the two formulated lubricants. Thus they are potential excellent running in lubricants for the cylinder liner piston ring pair.