고체표면에 응축된 물 분자의 윤활특성에 대한분자시뮬레이션 연구
Lubrication Characteristics of Condensed Water Moleculesat Solid Surface through Molecular Simulation
0
조회
0
다운로드
2
인용
0
참고문헌
키워드
초록
This paper presents a numerical analysis of the lubrication characteristics of condensed water molecules on a solid surface by conducting molecular dynamics simulations. We examine two models consisting of a simple hexahedral substrate with and without water molecules to reveal the lubrication mechanism of mono-layered water molecules. We perform a sliding simulation by contacting and translating a single asperity on the substrate under various normal loads. During the simulation, we measure the friction coefficient and atomic stress. When water molecules were interleaved between solid surfaces, atomic stress exerted on individual atom and friction coefficient were smaller than those of model without water molecule. Particularly, at a low load, the efficacy of water molecules in the reduction of atomic stress and friction is remarkable. Conversely, at high loads, water molecules rarely lubricate solid surfaces and fail to effectively distribute the contact stress. We found a critical condition in which the lubrication regime changes and beyond the condition, significant plastic deformation was created. Consequently, we deduce that water molecules can distribute and reduce contact stress within a certain condition. The reduced contact stress prevents plastic deformation of the substrate and thus diminishes the mechanical interlocking between the asperity and the substrate.
Abstract
This paper presents a numerical analysis of the lubrication characteristics of condensed water molecules on a solid surface by conducting molecular dynamics simulations. We examine two models consisting of a simple hexahedral substrate with and without water molecules to reveal the lubrication mechanism of mono-layered water molecules. We perform a sliding simulation by contacting and translating a single asperity on the substrate under various normal loads. During the simulation, we measure the friction coefficient and atomic stress. When water molecules were interleaved between solid surfaces, atomic stress exerted on individual atom and friction coefficient were smaller than those of model without water molecule. Particularly, at a low load, the efficacy of water molecules in the reduction of atomic stress and friction is remarkable. Conversely, at high loads, water molecules rarely lubricate solid surfaces and fail to effectively distribute the contact stress. We found a critical condition in which the lubrication regime changes and beyond the condition, significant plastic deformation was created. Consequently, we deduce that water molecules can distribute and reduce contact stress within a certain condition. The reduced contact stress prevents plastic deformation of the substrate and thus diminishes the mechanical interlocking between the asperity and the substrate.
참고문헌 (22)
- Tomala, A., "Tribological properties of additives for water-based lubricants", Wear, 269, pp.804~810 (2010)
- Wang, J., "Tribological behavior of PTFE sliding against steel in sea water", Wear, 267, pp.1634~1641 (2009)
- Pugh, K., "Some thoughts on mapping tribological issues of wind turbine blades due to effects of onshore and offshore raindrop erosion", Journal of Bio-and Tribo-Corrosion, 4, pp.1~8 (2018)
- Shinya Sasaki, "Environmentally friendly tribology (Eco-tribology)", Journal of Mechanical Science and Technology, 24(1), pp.67~71 (2010), 대한기계학회
- Song, J., "A molecular dynamics study on water lubrication of PTFE sliding against copper", Tribology International, 136, pp.234~239 (2019)
- 김혜균, "기판 종류에 따른 물 윤활 특성 및 나노 입자의 영향", 한국트라이볼로지학회지, 33(6), pp.245~250 (2017), 한국트라이볼로지학회[DOI]
- Ando, Y., "The effect of relative humidity on friction and pull-off forces measured on submicron-size asperity arrays", Wear, 238, pp.12~19 (2000)
- Chowdhury, M. A., "The effect of frequency of vibration and humidity on the coefficient of friction", Tribology International, 39, pp.958~962 (2006)
- Li, H., "Tribochemical effects on the friction and wear behaviors of diamond-like carbon film under high relative humidity condition", Tribology Letters, 19, pp.231~238 (2005)
- Tian, H., "The role of relative humidity, surface roughness and liquid build-up on static friction behavior of the head", disk interface, 1993
- Hernandez-Sanchez, E., "Effect of Relative Humidity on the Tribological Properties of Self-Lubricating H3BO3Films Formed on the Surface of Steel Suitable for Biomedical Applications", Advances in Materials Science and Engineering, 2015 (2015)
- Shi, J., "Friction and wear of hydrogenated and hydrogen-free diamond-like carbon films : relative humidity dependent character", Applied Surface Science, 422, pp.147~154 (2017)
- Tencer, M., "Humidity management of outdoor electronic equipment : methods, pitfalls, and recommendations", IEEE Transactions on Components and Packaging Technologies, 25, pp.66~72 (2002)
- Taylor, R. S., "Molecular dynamics simulations of the liquid", vapor interface of SPC, The Journal of Physical Chemistry, pp.1996, 100[DOI]
- Mark, P., "Structure and dynamics of the TIP3P, SPC, and SPC", E water models at 298K, 2001, pp.105, 9954~9960
- Sadus, R. J., "Molecular simulation of fluids" (2002), Elsevier
- Pei, Q., "Nanometric cutting of copper : A molecular dynamics study", Computational Materials Science, 37, pp.434~441 (2006)
- Xie, L., "Molecular dynamic simulation of binary ZrxCu100-x metallic glass thin film growth", Applied Surface Science, 274, pp.164~170 (2013)
- Zhang, Q., "Molecular dynamics simulation of water confined in a nanopore of amorphous silica", Molecular Simulation, 35, pp.1215~1223 (2009)
- Xu, Z., "Nanoengineering heat transfer performance at carbon nanotube interfaces", ACS nano, 3, pp.2767~2775 (2009)
- Subramaniyan, A. K., "Continuum interpretation of virial stress in molecular simulations", International Journal of Solids and Structures, 45, pp.4340~4346 (2008)
- Pöhl, F., "Pop-in behavior and elastic-to-plastic transition of polycrystalline pure iron during sharp nanoindentation", Scientific reports, 9, pp.1~12 (2019)