0
Research Papers: Elastohydrodynamic Lubrication

Experimental Analysis of Chromium Molybdenum Coatings Under Mixed Elastohydrodynamic Lubrication for Film Thickness, Friction, and Wear Characterizations

[+] Author and Article Information
David Pickens, III

Department of Mechanical Engineering,
Center for Surface Engineering and Tribology,
Northwestern University,
Evanston, IL 60208
e-mail: davidpickens2014@u.northwestern.edu

Zhong Liu

Department of Mechanical Engineering,
Center for Surface Engineering and Tribology,
Northwestern University,
Evanston, IL 60208
e-mail: zhongliu2018@u.northwestern.edu

Takayuki Nishino

Mazda Motor Corporation,
3-1, Shinchi, Fuchu-cho, Aki-gun,
Hiroshima 730-8670, Japan
e-mail: nishino.t@ae.auone-net.jp

Q. Jane Wang

Department of Mechanical Engineering,
Center for Surface Engineering and Tribology,
Northwestern University,
Evanston, IL 60208
e-mail: qwang@northwestern.edu

1Corresponding author.

Contributed by the Tribology Division of ASME for publication in the Journal of Tribology. Manuscript received August 9, 2018; final manuscript received March 9, 2019; published online April 12, 2019. Assoc. Editor: Wang-Long Li.

J. Tribol 141(6), 061502 (Apr 12, 2019) (11 pages) Paper No: TRIB-18-1319; doi: 10.1115/1.4043182 History: Received August 09, 2018; Accepted March 11, 2019

This research aims to evaluate the tribological performance of chromium molybdenum (CrMo) coatings under point and line-contact mixed elastohydrodynamic lubrication. This article studies the coatings made from two different methods and treated in an electrifying process of different durations, which produced microchannels and micropockets in the surfaces. The resulting surface topographies had varying impacts on lubricant film thickness, friction, and wear. Root-mean-square roughness (Sq) and porosity are used to characterize the surfaces and their performances in terms of film thickness, friction, and wear. The results suggest that the coated surfaces with a lower Sq and porosity density tended to yield higher film thickness. However, their influence on friction is complicated; lower roughness and porosity are preferred for lower wear, but certain levels of small roughness and surface pores may help to reduce boundary lubrication friction when compared with the frictional behaviors of porosity-free surfaces and those with higher roughness and higher porosity.

Copyright © 2019 by ASME
Your Session has timed out. Please sign back in to continue.

References

Spikes, H. A., 2006, “Sixty Years of EHL,” Lubr. Sci., 18(4), pp. 265–291. [CrossRef]
Holmberg, K., Andersson, P., and Erdemir, A., 2012, “Global Energy Consumption due to Friction in Passenger Cars,” Tribol. Int., 47, pp. 221–234. [CrossRef]
Kubiak, K. J., Liskiewicz, T. W., and Mathia, T. G., 2011, “Surface Morphology in Engineering Applications: Influence of Roughness on Sliding and Wear in Dry Fretting,” Tribol. Int., 44(11), pp. 1427–1432. [CrossRef]
Hirst, W., and Hollander, A. E., 1974, “Surface Finish and Damage in Sliding,” Proc. R. Soc., 337(Series A), pp. 379–394. [CrossRef]
Zhu, D., and Cheng, H., 1988, “Effect of Surface Roughness on Point Contact,” ASME J. Tribol., 110, pp. 32–37. [CrossRef]
Kaneta, M., Guo, F., Wang, J., Krupka, I., and Hartl, M., 2013, “Pressure Increase in Elliptical Impact of Elastohydrodynamic Lubrication Contacts With Longitudinal Aperities,” ASME J. Tribol., 135, p. 011503. [CrossRef]
Kaneta, M., Sakai, T., and Nishikawa, H., 1992, “Optical Interferometric Observations of the Effects of a Bump on Point Contact EHL,” ASME J. Tribol., 114, pp. 779–784. [CrossRef]
Kaneta, M., Tani, N., and Nishikawa, H., 2003, “Optical Interferometric Observations of the Effect of Moving Transverse Asperities on Point Contact EHL Films,” Tribol. Ser., 41, pp. 101–109. [CrossRef]
Kaneta, M., and Nishikawa, H., 1994, “Local Reduction in Thickness of Point Contact EHL Films Caused by a Transversely Oriented Moving Groove and Its Recovery,” ASME J. Tribol., 116, pp. 635–639. [CrossRef]
Choo, J. W., Olver, A. V., and Spikes, H., 2003, “Influence of Surface Roughness Features on Mixed-Film Lubrication,” Lubr. Sci., 15(3), pp. 219–232. [CrossRef]
Hartl, M., Křupka, I., Fuis, V., and Liška, M., 2004, “Experimental Study of Lubricant Film Thickness Behavior in the Vicinity of Real Asperities Passing Through Lubricated Contact,” Tribol. Trans., 47(3), pp. 376–385. [CrossRef]
Kaneta, M., Sakai, T., and Nishikawa, H., 1993, “Effects of Surface Roughness on Point Contact EHL,” Tribol. Trans., 36(4), pp. 605–612. [CrossRef]
Šperka, P., Křupka, I., and Hartl, M., 2012, “Prediction of Real Rough Surface Deformation in Pure Rolling EHL Contact: Comparison With Experiment,” Tribol. Trans., 55(5), pp. 698–704. [CrossRef]
Campos, M., and Torralba, J. M., 2004, “Surface Assessment in Low Alloyed Cr-Mo Sintered Steels After Heat and Thermochemical Treatment,” Surf. Coat. Technol., 182, pp. 351–362. [CrossRef]
Ye, X., Wang, J., Wang, H., and Yang, S., 2015, “A Novel Application of Mesoporous Silica Nanospheres on Effective Retention and Delivery of Lubricating Lil,” Microporous Mesoporous Mater., 204, pp. 131–136. [CrossRef]
Schlesinger, M., and Milan, P., 2001, Modern Electroplating (The ECS Series of Texts and Monographs), Wiley, New York.
Tanita, Y., Matsui, D., and Fukushima, H., 2011, “Study on Nanometer Size Structures in the Cr-Mo Electroplated Layer Using Transmission Electron Microscopy and Positron Lifetime Measurement,” Materi. Sci. Forum, 675–677, pp. 247–250. [CrossRef]
Zolper, T. J., Seyam, A., Li, Z., Chen, C., Jungk, M., Stammer, A., Marks, T. J., Chung, Y.-W., and Wang, Q., 2013, “Friction and Wear Protection Performance of Synthetic Siloxane Lubricants,” Tribol. Lett., 51(3), pp. 365–376. [CrossRef]
Zhu, D., and Jane Wang, Q., 2012, “On the λ Ratio Range of Mixed Lubrication,” Proc. Inst. Mech. Eng., Part J J. Eng. Tribol., 226(12), pp. 1010–1022. [CrossRef]
Liu, Y. C., Wang, Q. J., Wang, W. Z., Hu, Y. Z., and Zhu, D., 2006, “Effects of Differential Scheme and Mesh Density on EHL Film Thickness in Point Contacts,” ASME J. Tribol., 128(3), pp. 641–653. [CrossRef]
Liu, Y. C., Wang, Q. J., Zhu, D., Wang, W. Z., and Hu, Y. Z., 2009, “Effects of Differential Scheme and Viscosity Model on Rough-Surface Point-Contact Isothermal EHL,” ASME J. Tribol., 131(4), p. 044501. [CrossRef]
Liu, S., and Wang, Q., 2002, “Studying Contact Stress Fields Caused by Surface Tractions With a Discrete Convolution and Fast Fourier Transformation Algorithm,” ASME J. Tribol., 124, pp. 36–45. [CrossRef]
Liu, S., Wang, Q., and Liu, G., 2000, “A Versatile Method of Discrete Convolution and FFT (DC-FFT) for Contact Analyses,” Wear, 243, pp. 101–111. [CrossRef]
Hu, Y. Z., and Zhu, D., 2000, “A Full Numerical Solution to the Mixed Lubrication in Point Contacts,” ASME J. Tribol., 122(1), pp. 1–9. [CrossRef]
Patir, N., and Cheng, H. S., 1978, “An Average Flow Model for Determining Effects of Three-Dimensional Roughness on Partial Hydrodynamic Lubrication,” ASME J. Lubr. Tech., 100, pp. 12–17. [CrossRef]
Zhu, D., and Jane Wang, Q., 2013, “Effect of Roughness Orientation on the Elastohydrodynamic Lubrication Film Thickness,” ASME J. Tribol., 135(3), p. 031501. [CrossRef]
Zhu, D., Wang, J., and Wang, Q., 2015, “On the Stribeck Curves for Lubricated Counterformal Contacts of Rough Surfaces,” ASME J. Tribol., 137, p. 021501. [CrossRef]
Martini, A., Zhu, D., and Wang, Q., 2007, “Friction Reduction in Mixed Lubrication,” Tribol. Lett., 28(2), pp. 139–147. [CrossRef]
Meng, F., Zhou, R., Davis, T., Cao, J., Jane Wang, Q., Hua, D., and Liu, J., 2010, “Study on Effect of Dimples on Friction of Parallel Surfaces Under Different Sliding Conditions,” Appl. Surf. Sci., 256(9), pp. 2863–2875. [CrossRef]
Yu, C., and Jane Wang, Q., 2012, “Friction Anisotropy with Respect to Topographic Orientation,” Sci. Rep., 2(1), p. 988. [CrossRef] [PubMed]
Sochi, T., 2010, “Non-Newtonian Flow in Porous Media,” Polymer, 51(22), pp. 5007–5023. [CrossRef]
Yilmaz, N., Bakhtiyarov, A. S., and Ibragimov, R. N., 2009, “Experimental Investigation of Newtonian and Non-Newtonian Fluid Flows in Porous Media,” Mech. Res. Commun., 36(5), pp. 638–641. [CrossRef]

Figures

Grahic Jump Location
Fig. 1

Optical images of a coated ball surface: (a) microchannels by coating method A and (b) micropockets by coating method B

Grahic Jump Location
Fig. 8

Film thickness as a function of RMS roughness and porosity at 750 mm/s and 100 °C: (a) RMS roughness and (b) porosity

Grahic Jump Location
Fig. 9

Simulated interaction areas for film thickness test at 550 mm/s. (a) Uncoated, (b) A-80-1, (c) B-80-1, (d) B-80-2, and (e) B-80-6. White circles at the center represent 4% of the interaction, where the average film thickness was calculated at each time step.

Grahic Jump Location
Fig. 10

Simulated interaction areas for film thickness test at 4.3 m/s. (a) Uncoated, (b) A-80-1, (c) B-80-1, (d) B-80-2, and (e) B-80-6. White circles at the center represent 4% of the interaction, where the average film thickness was calculated at each time step.

Grahic Jump Location
Fig. 11

Calculated average film thickness at speed (a) 550 mm/s and (b) 4.3 m/s

Grahic Jump Location
Fig. 12

Pin-on-disk friction between steel ball and uncoated and coated disks at 100 °C at 500 mm/s.

Grahic Jump Location
Fig. 13

Point-contact friction (steady state) between fixed polished steel ball and coated (and uncoated) disks as a function of (a) Sq and (b) porosity at 100 °C at 500 mm/s. Note that the friction datum for specimen B-80-1 is overlapped with those of the other disks due to the closeness in Sq and porosity values.

Grahic Jump Location
Fig. 7

Lambda ratio (black markers) and central film thickness (white markers) versus the entrainment speed of uncoated (circles), and A-80-1 (stars), B-80-1 (squares), B-80-1 (crosses), B-80-6 (upward pointing triangles) coated balls at (a) 40 °C and (b) 100 °C

Grahic Jump Location
Fig. 6

Film thickness versus speed for the uncoated (circles), A-80-1 (squares), B-80-1 (stars), B-80-2 (crosses), and B-80-6 (upward pointing triangles) balls tested at (a) 40 °C and (b) 100 °C under pure rolling conditions

Grahic Jump Location
Fig. 5

Line-contact test setup using an apex seal specimen: (a) apex seals, (b) cut apex seal specimen, and (c) side view of the line-contact specimen holder

Grahic Jump Location
Fig. 4

Sq and volume porosity of disks in Fig. 2 as a function of the electrifying time: (a) type A and (b) type B

Grahic Jump Location
Fig. 3

3D surface topographies of disks: (a) disk B-80-1 and (b) reference disk for maximum porosity

Grahic Jump Location
Fig. 2

Surface topographic images of several coated disk samples (145 μm × 110 μm area): (a) A-80-1 (14 μm maximum depth), (b) A-80-2 (12 μm maximum depth), (c) A-80-6 (25 μm maximum depth), (d) B-80-1 (1 μm maximum depth), (e) B-80-2 (8 μm maximum depth), and (f) B-80-6 (16 μm maximum depth)

Grahic Jump Location
Fig. 14

Friction results from the line-contact tests at room temperature at 4 N: (a) friction as a function of speed and (b) standard deviation as a function of time of Fig. 14(a)

Grahic Jump Location
Fig. 15

Line-contact friction coefficients at 1 mm/s of Fig. 14 as a function of (a) RMS roughness and (b) porosity

Grahic Jump Location
Fig. 16

Effects of mean surface height on friction: (a) point-contact friction test results, friction data from Fig. 13(b) and line-contact friction test results, data from Fig. 14

Grahic Jump Location
Fig. 17

Wear void volume of the coated and uncoated disks at 2.3 GPa

Grahic Jump Location
Fig. 18

Ball wear void volume as a function of (a) RMS roughness and (b) porosity. Note that in (a), the wear datum for B-80-1 overlaps with that for B-80-2 because of the same Sq value.

Tables

Errata

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In