| Sliding bearings,as key parts of diesel engines,can avoid direct contact and wear between the piston pin and the connecting rod and prolong the service life of the connecting rod.With the continuous development of diesel engines in the direction of heavy load,high speed and high specific pressure,higher requirements are put forward for the ultimate load,wear resistance,seizure resistance and high temperature resistance of sliding bearings,and their service life is facing more severe tests.In practical applications,the common failure mode of sliding bearings is wear failure.Therefore,studying the friction and wear characteristics of sliding bearing materials is of great significance to prolong its service life.In this paper,Cu-Ni-Sn and QSn7-0.2 sliding bearing materials are selected as the research objects,and the piston pin material 12 Cr Ni3A is used as the counter-grinding material.The pin-disc dry friction and wear tests are carried out,and the friction and wear characteristics under different loads and speeds are studied.The surface morphology and element composition of the friction and wear samples were systematically analyzed by scanning electron microscope,energy spectrometer,3D optical surface profiler and other micro-detection methods,and the characteristics of copper-nickel-tin and tin-bronze sliding bearing materials under different conditions were discussed.The main wear mechanism and its transformation process.Research shows that under different loads and speeds,the friction coefficient of Cu-Ni-Sn fluctuates less,the friction coefficient of QSn7-0.2 fluctuates greatly,and the friction coefficient of Cu-Ni-Sn is more stable.When the load continues to increase,the abrasion of Cu-Ni-Sn and QSn7-0.2 continues to increase;when the rotating speed increases,the abrasion of Cu-Ni-Sn and QSn7-0.2 first decreases and then increases.The abrasion of Cu-Ni-Sn and QSn7-0.2 under the same test conditions Always less than the amount of wear of QSn7-0.2.Under different loads and speeds,the main wear mechanisms of Cu-Ni-Sn are abrasive wear,oxidative wear and adhesive wear;the main wear mechanisms of QSn7-0.2 are abrasive wear,fatigue wear and adhesive wear.In summary: the friction and wear performance of Cu-Ni-Sn and is better than that of QSn7-0.2. |
