Experimental Study of Effect of Humidity on Structural Changes of “Third Body” During Friction

Friction is often accompanied by local fracture at the boundary of the contacting bodies. The gap between the bodies usually contains moving particles of different origin (third body), a change in the effective friction conditions may be associated with some changes in the structure of the “third body”. This paper presents a new series of experiments in which the process of rearrangement of intermediate layer particles interacting with various elastic materials (glass-rubber and steel) is modeled at different scale levels. A technique for visualizing the effect of mutual influence that occurs when two balls are pressed into a layer of rubber is proposed. It is the mutual influence that causes the effect of convergence or separation of the balls or particles during reciprocating frictional loading. The velocity of these processes depends on humidity and, in case of contact with the rubber layer, on the thickness of the layer. At high humidity, the configuration of the particles changes faster, and the friction force decreases. Replacing sand with an abrasive leads to increase in the coefficient of friction and wear with a change in the microrelief of the surface. The minimum roughness is obtained for a humidity of 30 %.

1. Marchenko E. About the nature of fracture of metal surfaces by friction. — Moscow: Nauka. — 1979 (in Russian)

2. Goldstein R.V., Osipenko N.M. The mechanism of movement in a medium of the intermediate layer between the contacting bodies // Letters on Materials. — 2015 (5), № 4, 414—419. https://doi.org/10.22226/2410-3535-2015-4-414-419 (in Russian)

3. Andronov V.V. Mechanical systems with transformed dry friction // Mech. Solids. — 1988, № 1, 40—49 (in Russian)

4. Miftakhova A.R., Chen Y.Y., and Horng J.H. Effect of Rolling on the Friction Coefficient in ThreeBody Contact //Advances in Mechanical Engineering. — 2019 (11), no. 8, 1687814019872303. https://doi.org/10.1177/168781401987230

5. Horng J.H., Osipenko N.M., Stepanov F.I., and Torskaya E.V. Theoretical and Experimental Study of Changes in the Structure of the Intermediate Layer during Friction between Contacting Bodies // Materials. — 2021 (14), no. 19, 5689. https://doi.org/10.3390/ma14195689

6. Klaffke D. On the Repeatability of Friction and Wear Results and on the Influence of Humidity in Oscillating Sliding Tests of Steel-Steel Pairings // Wear. — 1995 (189), nos. 1-2, 117—121. https://doi.org/10.1016/0043-1648(95)06672-1

7. Lancaster J.K. A Review of the Influence of Environmental Humidity and Water on Friction, Lubrication and Wear // Tribology International. — 1990 (23), no. 6, 371—389. https://doi.org/10.1016/0301-679X(90)90053-R

8. Liew W.Y.H. Effect of Relative Humidity on the Unlubricated Wear of Metals // Wear. — 2006 (260), nos. 7-8, 720—727. https://doi.org/10.1016/j.wear.2005.04.011

9. Bregliozzi G., Ahmed S.U., Di Schino A., Kenny J.M., and Haefke H. Friction and Wear Behavior of Austenitic Stainless Steel: Influence of Atmospheric Humidity, Load Range, and Grain Size // Tribology Letters. — 2004 (17), 697—704. https://doi.org/10.1007/s11249-004-8075-z

10. Reichelt M. and Cappella B. Influence of Relative Humidity on Wear of Self-Mated 100Cr6 Steel // Wear. — 2020 (450), 203239. https://doi.org/10.1016/j.wear.2020.203239

11. Kumar A. and Mukhopadhyay A. Investigation of Reciprocating Wear Characteristics of Carbon Steel at Varying Load, Relative Humidity, and Operating Temperature Using ANN-NSGA Methodology // Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering. — 2023, 09544089221149404. https://doi.org/10.1177/09544089221149404

12. Chen L. and Qian L. Role of Interfacial Water in Adhesion, Friction, and Wear — A Critical Review // Friction. — 2021 (9), 1—28. https://doi.org/10.1007/s40544-020-0425-4

13. Xiao C., Shi P., Yan W., Chen L., Qian L., and Kim S.H. Thickness and Structure of Adsorbed Water Layer and Effects on Adhesion and Friction at Nanoasperity Contact // Colloids and Interfaces. — 2019 (3), no. 3, 55. https://doi.org/10.3390/col-loids3030055

14. Rong K.J., Xiao Y.L., Shen M.X., Zhao H.P., Wang W.J., and Xiong G.Y. Influence of Ambient Humidity on the Adhesion and Damage Behavior of Wheel–Rail Interface under Hot Weather Condition // Wear. — 2021 (486), 204091. https://doi.org/10.1016/j.wear.2021.204091

15. Shengxin L., Jiaqiang L., Lin L., Shaopeng L., Lizhi H., Guangyao X., and Mingxue S. Response Behavior of Damp-Warm Air to Adhesion and Damage of Wheel-Rail Interface at Different Ambient Temperatures // Tribology. — 2022 (43), no. 1, 30—38. doi: 10.16078/j.tribology.2022105