Hostname: page-component-78c5997874-8bhkd Total loading time: 0 Render date: 2024-11-08T07:59:35.701Z Has data issue: false hasContentIssue false

The effect of density and surface topography on the coefficient of friction of polytetrafluoroethylene films

Published online by Cambridge University Press:  28 August 2020

Mathew Brownell
Affiliation:
Multiscale Materials Modeling Lab, Department of Mechanical Engineering, University of Arkansas, Fayetteville, AR, USA.
Arun K. Nair*
Affiliation:
Multiscale Materials Modeling Lab, Department of Mechanical Engineering, University of Arkansas, Fayetteville, AR, USA. Institute for Nanoscience and Engineering, 731 W. Dickson Street, University of Arkansas, Fayetteville AR-72701.
*
*Corresponding author, electronic address: [email protected]; Phone: +479-575-2573, Fax: +479-575-6982
Get access

Abstract

Polytetrafluoroethylene (PTFE) film is observed to increase surface roughness during annealing. Longer annealing times leads to greater surface roughness. The coefficient of friction of PTFE film is affected by the shape of microscale sized particles on the film surface. In this study, we investigate the coefficient of friction of PTFE films using a coarse-grained molecular dynamics model based on experimental observations. We observe how the variation in PTFE chain length and film density affect the topography of PTFE films. We also investigate how these properties of PTFE, and the indenter radius affect the coefficient of friction observed during surface scratch. We find that short PTFE chain lengths create a dense film with greater particle spacing, but longer chains form a mesh structure which reduces the density and creates overlapping portions of particles in the film. We develop a convolutional neural network to classify PTFE film surface and predict the coefficient of friction of a modeled film based solely on the equilibrated film topography. The accuracy of the network was seen to increase when the density and images of internal fiber orientation were added as input features. These results indicate that the coefficient of friction of PTFE films in part is governed by the internal structure of the film.

Type
Articles
Copyright
Copyright © Materials Research Society 2020

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Flom, D. and Porile, N., “Friction of teflon sliding on teflon,” Journal of Applied Physics, vol. 26, no. 9, pp. 10881092, 1955.CrossRefGoogle Scholar
Vijayan, K. and Biswas, S., “Wear of polytetrafluoroethylene: some crystallographic observations,” Wear, vol. 150, no. 1–2, pp. 267273, 1991.CrossRefGoogle Scholar
Biswas, S. and Vijayan, K., “Friction and wear of PTFE—a review,” Wear, vol. 158, no. 1–2, pp. 193211, 1992.CrossRefGoogle Scholar
Sawyer, W. G., Freudenberg, K. D., Bhimaraj, P., and Schadler, L. S., “A study on the friction and wear behavior of PTFE filled with alumina nanoparticles,” Wear, vol. 254, no. 5–6, pp. 573580, 2003.Google Scholar
Tanaka, K. and Kawakami, S., “Effect of various fillers on the friction and wear of polytetrafluoroethylene-based composites,” Wear, vol. 79, no. 2, pp. 221234, 1982.CrossRefGoogle Scholar
Burris, D. L. and Sawyer, W. G., “A low friction and ultra low wear rate PEEK/PTFE composite,” Wear, vol. 261, no. 3–4, pp. 410418, 2006.CrossRefGoogle Scholar
Beckford, S., Cai, J., Chen, J., and Zou, M., “Use of Au nanoparticle-filled PTFE films to produce low-friction and low-wear surface coatings,” Tribology Letters, vol. 56, no. 2, pp. 223230, 2014.CrossRefGoogle Scholar
Jiang, Y., Choudhury, D., Brownell, M., Nair, A., Goss, J. A., and Zou, M., “The effects of annealing conditions on the wear of PDA/PTFE coatings,” Applied Surface Science, 2019.Google Scholar
Pan, D., Fan, B., Qi, X., Yang, Y., and Hao, X., “Investigation of PTFE tribological properties using molecular dynamics simulation,” Tribology Letters, vol. 67, no. 1, p. 28, 2019.CrossRefGoogle Scholar
Wood, M. A., Van Duin, A. C., and Strachan, A., “Coupled thermal and electromagnetic induced decomposition in the molecular explosive αHMX; a reactive molecular dynamics study,” The Journal of Physical Chemistry A, vol. 118, no. 5, pp. 885895, 2014.CrossRefGoogle ScholarPubMed
D'Amore, M., Talarico, G., and Barone, V., “Periodic and high-temperature disordered conformations of polytetrafluoroethylene chains: an ab initio modeling,” Journal of the American Chemical Society, vol. 128, no. 4, pp. 10991108, 2006.CrossRefGoogle Scholar
Brownell, M. and Nair, A. K., “Deformation mechanisms of polytetrafluoroethylene at the nano-and microscales,” Physical Chemistry Chemical Physics, vol. 21, no. 1, pp. 490503, 2019.CrossRefGoogle Scholar
Beckford, S. and Zou, M., “Wear resistant PTFE thin film enabled by a polydopamine adhesive layer,” Applied Surface Science, vol. 292, pp. 350356, 2014.CrossRefGoogle Scholar
Beckford, S., Mathurin, L., Chen, J., Fleming, R. A., and Zou, M., “The effects of polydopamine coated Cu nanoparticles on the tribological properties of polydopamine/PTFE coatings,” Tribology International, vol. 103, pp. 8794, 2016.Google Scholar
Gu, G. X., Chen, C.-T., and Buehler, M. J., “De novo composite design based on machine learning algorithm,” Extreme Mechanics Letters, vol. 18, pp. 1928, 2018.CrossRefGoogle Scholar
Takahashi, K. and Tanaka, Y., “Material synthesis and design from first principle calculations and machine learning,” Computational materials science, vol. 112, pp. 364367, 2016.CrossRefGoogle Scholar
Foster, K. R., Koprowski, R., and Skufca, J. D., “Machine learning, medical diagnosis, and biomedical engineering research-commentary,” Biomedical engineering online, vol. 13, no. 1, p. 94, 2014.CrossRefGoogle ScholarPubMed
Humphrey, W., Dalke, A., and Schulten, K., “VMD: visual molecular dynamics,” Journal of molecular graphics, vol. 14, no. 1, pp. 3338, 1996.CrossRefGoogle ScholarPubMed
Weidner, V. R. and Hsia, J. J., “Reflection properties of pressed polytetrafluoroethylene powder,” Josa, vol. 71, no. 7, pp. 856861, 1981.CrossRefGoogle Scholar
Plimpton, S., “Fast parallel algorithms for short-range molecular dynamics,” Journal of computational physics, vol. 117, no. 1, pp. 119, 1995.CrossRefGoogle Scholar
Gao, J., Luedtke, W., Gourdon, D., Ruths, M., Israelachvili, J., and Landman, U., “Frictional forces and Amontons' law: from the molecular to the macroscopic scale,” ed: ACS Publications, 2004.Google Scholar
Barry, P. R., Chiu, P. Y., Perry, S. S., Sawyer, W. G., Sinnott, S. B., and Phillpot, S. R., “Effect of temperature on the friction and wear of PTFE by atomic-level simulation,” Tribology Letters, vol. 58, no. 3, p. 50, 2015.Google Scholar
Shen, J., Top, M., Pei, Y., and De Hosson, J. T. M., “Wear and friction performance of PTFE filled epoxy composites with a high concentration of SiO2 particles,” Wear, vol. 322, pp. 171180, 2015.CrossRefGoogle Scholar
McLaren, K. and Tabor, D., “Visco-elastic properties and the friction of solids: friction of polymers: influence of speed and temperature,” Nature, vol. 197, no. 4870, p. 856, 1963.CrossRefGoogle Scholar
Supplementary material: PDF

Brownell and Nair supplementary material

Brownell and Nair supplementary material

Download Brownell and Nair supplementary material(PDF)
PDF 395.5 KB