Experimental study of the tribological characteristics of a honed cylinder liner during the running-in process

The tribological properties of the cylinder liner are of great significance in reducing energy loss from an internal combustion engine's system. In order to improve the antiwear performance of the cylinder liner at top dead center (TDC), the friction and wear of the honed cylinder liner during the running-in process are investigated. Using a UMT TriboLab multifunction friction wear tester, the coefficients of friction (COFs) are analyzed under different lubrication conditions and loads, and the surface roughness and profile of the cylinder liner are obtained using a three-dimensional (3D) laser scanning confocal microscope (LSCM). The COF, roughness and surface profile are compared in order to investigate the variation in tribology parameters under different operating conditions. To monitor the COF in real time, it is predicted using the polynomial fitting method. It is shown that the COF decreases with an increase in the lubrication oil and load and that the surface profile more easily becomes smooth under dry (lubrication) conditions; this can effectively shorten the operation time during the running-in process. The polynomial fitting method can achieve an assessment of the COF with a very small standard error.