DOI: 10.5061/dryad.zpc866thd
title: Atomic force microscopy of transfer film development

description: Atomic force microscopy (AFM) provides the opportunity to perform
 fundamental and mechanistic observations of complex, dynamic, and
 transient systems and ultimately link material microstructure and its
 evolution during tribological interactions. This investigation focuses on
 the evolution of a dynamic fluoropolymer tribofilm formed during sliding
 of polytetrafluoroethylene (PTFE) mixed with 5 wt% alpha-phase alumina
 particles against 304L stainless steel. Sliding was periodically
 interrupted for AFM topography scans. The average film roughness, the
 average friction coefficient, and polymer wear rate based on sample height
 recession were recorded as a function of increasing sliding cycles.
 Topographical maps suggest tribofilm nucleates in grooves of the steel
 counter sample, spreads and develops into a uniform film through sliding.
 Prominent nanoscale features were visible around 10,000 sliding cycles and
 thereafter. Scanning electron microscopy and energy-dispersive X-ray
 spectroscopy showed good correlations between these features and
 aluminum-rich domains, suggesting the presence of alumina particles on the
 surface.
description: # Atomic force microscopy of transfer film development
 [https://doi.org/10.5061/dryad.zpc866thd](https://doi.org/10.5061/dryad.zpc866thd) Corresponding Author: Angela A. Pitenis [apitenis@ucsb.edu](mailto:apitenis@ucsb.edu) File List A) AFM_Region_1.zip B) AFM_Region_2.zip C) AFM_Region_3.zip D) AFM_Region_4.zip E) Countersurface.zip F) Fig3_AverageRoughness.csv G) Fig3_FrictionAndWear.csv H) Fig5_Al.tif I) Fig5_SI.tif J) Fig6.csv K) FigS1_0s.tif L) FigS1_5s.tif M) FigS1_10s.tif N) FigS2_10k.tif O) FigS2_20k.tif P) FigS2_30k.tif Q) FigS2_40k.tif R) FigS2_50k.tif S) FigS2_100k.tif T) FigS2_all.jpg U) FigS3.csv V) FigS4_10k.ibw W) FigS4_20k.ibw X) FigS4_30k.ibw Y) FigS4_40k.ibw Z) FigS4_50k.ibw AA) FigS4_100k.ibw AB) FigS5.csv ## Figures 1, 2, 4, SV1: AFM Data A) AFM_Region_1.zip: zip folder containing IBW files for each AFM scan done in region 1 on the primary sample. These files are labeled Region1_Cycle_X, where X is the cycle number the AFM scan was taken. IBW files may be opened using Gwyddion, a free scanning probe microscopy data analysis software. B) AFM_Region_2.zip: zip folder containing IBW files for each AFM scan done in region 2 on the primary sample. These files are labeled Region2_Cycle_X, where X is the cycle number the AFM scan was taken. IBW files may be opened using Gwyddion, a free scanning probe microscopy data analysis software. C) AFM_Region_3.zip: zip folder containing IBW files for each AFM scan done in region 3 on the primary sample. These files are labeled Region3_Cycle_X, where X is the cycle number the AFM scan was taken. IBW files may be opened using Gwyddion, a free scanning probe microscopy data analysis software. D) AFM_Region_4.zip: zip folder containing IBW files for each AFM scan done in region 4 on the primary sample. These files are labeled Region4_Cycle_X, where X is the cycle number the AFM scan was taken. IBW files may be opened using Gwyddion, a free scanning probe microscopy data analysis software. ## Figures 1, 2, SV1: Countersurface Images E) Countersurface.zip: zip folder containing JPG images of the countersurface of the primary sample. These files are labeled Countersurface_Cycle_X, where X is the cycle number the AFM scan was taken. ## Figure 3, SV1: Roughness, Friction and Wear Data F) Fig3_AverageRoughness.csv: average roughness values for countersurface of the primary sample. * Row 1: labels for column data with units * Column A: number of sliding cycles * Column B: average roughness, in nanometers * Column C: uncertainty in average roughness, in nanometers G) Fig3_FrictionAndWear.csv: coefficient of friction and wear rate values for the primary sample. * Row 1: labels for column data with units * Column A: number of sliding cycles * Column B: average friction coefficient, unitless * Column C: uncertainty in average friction coefficient, unitless * Column D: wear rate, in millimeters cubed per Newton-meter ## Figure 5: SEM micrograph H) Fig5_Al.tif: EDX map of the countersurface of the stripe test sample after 50,000 sliding cycles displaying of location of aluminum, in purple. Brighter purple indicates a greater abundance of aluminum. I) Fig5_SI.tif: secondary electron micrograph of the countersurface of the stripe test sample after 50,000 sliding cycles. ## Figure 6: PSD data J) Fig6.csv: power spectral density data for the primary sample countersurface taken from AFM maps for representative sliding cycles. Data was produced on the contact.engineering web platform and can be found at [https://doi.org/10.57703/ce-p4z34](https://doi.org/10.57703/ce-p4z34). * Row 1: labels the number of sliding cycles for the two columns below the label * Row 2: Labels for column data with units * Column A: Wavevector for 0 sliding cycles, in inverse meters * Column B: Power spectral density for 0 sliding cycles, in meters cubed * Column D: Wavevector for 5,000 sliding cycles, in inverse meters * Column E: Power spectral density for 5,000 sliding cycles, in meters cubed * Column G: Wavevector for 10,000 sliding cycles, in inverse meters * Column H: Power spectral density for 10,000 sliding cycles, in meters cubed * Column J: Wavevector for 100,000 sliding cycles, in inverse meters * Column K: Power spectral density for 100,000 sliding cycles, in meters cubed ## Figure S1: SEM micrographs K) FigS1_0s.tif: secondary electron micrograph of the countersurface of the stripe test sample after 50,000 sliding cycles taken as blisters began forming. L) FigS1_5s.tif: secondary electron micrograph of the countersurface of the stripe test sample after 50,000 sliding cycles taken 5s after blisters began forming. M) FigS1_10s.tif: secondary electron micrograph of the countersurface of the stripe test sample after 50,000 sliding cycles taken 10s after blisters began forming. ## Figure S2: Countersurface Images N) FigS2_10k.tif: micrograph of the stripe test countersurface at 10,000 sliding cycles O) FigS2_20k.tif: micrograph of the stripe test countersurface at 20,000 sliding cycles P) FigS2_30k.tif: micrograph of the stripe test countersurface at 30,000 sliding cycles Q) FigS2_40k.tif: micrograph of the stripe test countersurface at 40,000 sliding cycles R) FigS2_50k.tif: micrograph of the stripe test countersurface at 50,000 sliding cycles S) FigS2_100k.tif: micrograph of the stripe test countersurface at 100,000 sliding cycles T) FigS2_all.jpg: image of the entire stripe test countersurface ## Figure S3: Wear Rate U) FigS3.csv: wear rate of the stripe test sample * Row 1: labels for column data with units * Column A: sliding distance, in meters * Column D: wear rate, in millimeters cubed per Newton-meter ## Figure S4: AFM Images V) FigS4_10k.ibw: representative AFM image of the stripe test sample in the region that was slid for 10,000 sliding cycles. IBW files may be opened using Gwyddion, a free scanning probe microscopy data analysis software. W) FigS4_20k.ibw: representative AFM image of the stripe test sample in the region that was slid for 20,000 sliding cycles. IBW files may be opened using Gwyddion, a free scanning probe microscopy data analysis software. X) FigS4_30k.ibw: representative AFM image of the stripe test sample in the region that was slid for 30,000 sliding cycles. IBW files may be opened using Gwyddion, a free scanning probe microscopy data analysis software. Y) FigS4_40k.ibw: representative AFM image of the stripe test sample in the region that was slid for 40,000 sliding cycles. IBW files may be opened using Gwyddion, a free scanning probe microscopy data analysis software. Z) FigS4_50k.ibw: representative AFM image of the stripe test sample in the region that was slid for 50,000 sliding cycles. IBW files may be opened using Gwyddion, a free scanning probe microscopy data analysis software. AA) FigS4_100k.ibw: representative AFM image of the stripe test sample in the region that was slid for 100,000 sliding cycles. IBW files may be opened using Gwyddion, a free scanning probe microscopy data analysis software. ## Figure S5: PSD Data AB) FigS5.csv: power spectral density data for the stripe test sample countersurface taken from AFM maps for representative sliding cycles. Data was produced on the contact.engineering web platform and can be found at [https://doi.org/10.57703/ce-4sty6](https://doi.org/10.57703/ce-4sty6). * Row 1: labels the number of sliding cycles for the two columns below the label * Row 2: Labels for column data with units * Column A: Wavevector for 10,000 sliding cycles, in inverse meters * Column B: Power spectral density for 10,000 sliding cycles, in meters cubed * Column D: Wavevector for 20,000 sliding cycles, in inverse meters * Column E: Power spectral density for 20,000 sliding cycles, in meters cubed * Column G: Wavevector for 30,000 sliding cycles, in inverse meters * Column H: Power spectral density for 30,000 sliding cycles, in meters cubed * Column J: Wavevector for 40,000 sliding cycles, in inverse meters * Column K: Power spectral density for 40,000 sliding cycles, in meters cubed * Column M: Wavevector for 50,000 sliding cycles, in inverse meters * Column N: Power spectral density for 50,000 sliding cycles, in meters cubed * Column P: Wavevector for 100,000 sliding cycles, in inverse meters * Column Q: Power spectral density for 100,000 sliding cycles, in meters cubed ## Code/Software IBW files may be opened using Gwyddion, a free scanning probe microscopy data analysis software available at http://gwyddion.net/.