Combined effect of boundary layer formation and surface smoothing on friction and wear rate of lubricated point contacts during normal running-in processes
- 163 Downloads
The combined effect of boundary layer formation and surface smoothing on friction and wear rate of metallic surfaces under lubricated point contact condition was investigated. The double trend of friction coefficient variations was revealed during running-in and sub-running-in processes. The evolution of surface topography was measured on-site using white-light interference profilometer and analyzed using bearing area curves. Comprehensive theoretical equations that explicitly express the contributions of boundary friction, adhesive friction and wear have been derived, and results obtained by these equations were compared with experimental observations. It is concluded that the theoretical models are quantitatively adequate to describe the combined effect of surface smoothing due to mechanical wear and formation of boundary films on the changes in friction and wear rate during normal running-in processes.
Keywordsrunning-in bearing area curves friction modeling wear modeling mixed lubrication
This work was partially supported by NSFC under grant No. 51635009 and by the State Administration of Foreign Expert Affairs under grant No. DL2017QHDX001.
- Blau P J. Running-in. In Encyclopedia of Tribology. Wang Q J, Chung Y W, Eds. Boston, MA: Springer, 2013: 2967–2969.Google Scholar
- Goryacheva I G. Wear models. In Contact Mechanics in Tribology. Goryacheva I G, Ed. Dordrecht: Springer, 1998: 163–190.Google Scholar
- Raymond G B. Mechanical Wear Fundamentals and Testing. 2nd ed. New York (USA): Marcel Dekker Inc., 2004.Google Scholar
- Straffelini G. Wear processes. In Friction and Wear: Methodologies for Design and Control. Straffelini G, Ed. Cham: Springer, 2015: 115–158.Google Scholar
- Bair S S. High Pressure Rheology for Quantitative Elastohydrodynamics. Amsterdam (Netherlands), Boston (USA): Elsevier, 2007.Google Scholar
- Abbott E J, Firestone F A. Specifying surface quality. Mech Eng, 55: 569–572 (1933)Google Scholar
- DIN 4776. Kenngrößen Rk, Rpk, Rvk, Mr1, Mr2 zur Beschreibug des Materialanteils im Rauheitsprofil— Meßbedingungen und Auswerteverfahren. In Deutsche Norm. Berlin: Beuth Verlag GmbH, 1990.Google Scholar
- ISO. ISO 25178–2: 2012 Geometrical Product Specifications GPS)–Surface texture: Areal–Part 2: Terms, definitions and surface texture parameters. ISO, Geneva, 2012.Google Scholar