Effect of scan size and surface roughness on microscale friction measurements

Abstract Friction measurements have been carried out to characterize surface damages during photodegradation of low-density polyethylene. The average and mean deviation of the friction coefficients increase with the irradiation time in the early stage of photodegradation processes, indicating the increase in the surface roughness, whereas the mechanical properties remain essentially unchanged. In the following stage, where the ductile-brittle transition takes place, the mean deviation of the friction coefficients shows an appreciable decrease with maintaining almost constant average values, suggesting that the surface becomes more homogeneous. Beyond the ductile-brittle transition, both of the average and mean deviation of the friction coefficients gradually increase with the irradiation time, indicating further enhancement of surface roughness, followed by formation of surface cracks. The soundness of the friction measurements is confirmed by comparing with optical measurements of the surface roughness, and it is suggested that the present method gives a convenient and sensitive method of detection for degradation in polymeric materials.

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Improved Slip-Resistance on Oil from Surface Roughness of Footwear

Rubber Chemistry and Technology ◽

10.5254/1.3538150 ◽

1983 ◽

Vol 56 (4) ◽

pp. 703-717 ◽

Cited By ~ 20

Author(s):

D. P. Manning ◽

C. Jones ◽

M. Bruce

Keyword(s):

Surface Roughness ◽

Surface Texture ◽

Cellular Structure ◽

Ceramic Tiles ◽

Slip Resistance ◽

Changing Patterns ◽

Friction Measurements ◽

Single Material

Abstract This appears 10 be the first published investigation of friction measurements throughout the useful lives of footwear, and the changing patterns of slip-resistance found justify this approach. The polishing effect of walking on some surfaces needs further investigation, and there should now be an evaluation of friction relative to surface texture of soles and heels. It may be possible to engineer a permanent surface roughness by varying composition and size of spaces in a cellular structure. Although it is unlikely that any single material will prove to be satisfactory for all types of floor hazards, our experience with polyurethane is encouraging. If it proves impossible to find a single material giving adequate slip-resistance on wet or icy pavements, wet PVC tiles, ceramic tiles contaminated with grease and water, and factory floors contaminated with oil, then materials should be specified for each type of hazard.

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Surface characterization of paper and paperboard using a stylus contact method

Nordic Pulp & Paper Research Journal ◽

10.1515/npprj-2019-0005 ◽

2020 ◽

Vol 35 (1) ◽

pp. 78-88

Author(s):

Young Chan Ko ◽

Lili Melani ◽

Na Young Park ◽

Hyoung Jin Kim

Keyword(s):

Surface Roughness ◽

Surface Characterization ◽

Paper Industry ◽

Surface Friction ◽

Operating Conditions ◽

Contact Method ◽

Measuring Surface ◽

Two Samples ◽

Friction Measurements

AbstractSurface characterization is important and has many applications in the paper industry. Surface characterization requires both surface roughness and surface friction. The relationship between the two has not been fully established for paper and paperboard. It has been a common practice that only the average property and the standard deviation with the coefficient of variation (COV) are reported for surface roughness and friction measurements. This practice, however, provides few information on surface structure and can lead to wrong judgments because two samples having the same average and the COV can have different physical properties. To avoid such mistake, a new surface characterization method has been developed. To this end, surface roughness- and friction-profiles have been obtained using a latest version of Kawabata surface tester (Model: KES-SESRU, Kato Tech, Kyoto Japan). This new version uses the same stylus for both measuring surface roughness and friction under the same operating conditions. It was found that a correlation between the surface roughness and surface friction was very low. This indicates that they should be independent of each other. Therefore, both should be determined for surface characterization.

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Atomic-Scale Friction Measurements Using Friction Force Microscopy: Part II—Application to Magnetic Media

Journal of Tribology ◽

10.1115/1.2927241 ◽

1994 ◽

Vol 116 (2) ◽

pp. 389-396 ◽

Cited By ~ 102

Author(s):

Bharat Bhushan ◽

Ju-Ai Ruan

Keyword(s):

Surface Roughness ◽

Friction Force ◽

Coefficient Of Friction ◽

Natural Diamond ◽

Local Variation ◽

Atomic Scale ◽

Poor Correlation ◽

Magnetic Media ◽

Micro Scale ◽

Friction Measurements

Atomic Force/Friction Force Microscopes (AFM/FFM) were used to study tribological properties of metal-particle tapes with two roughnesses, Co-γFe2O3 tapes (unwiped and wiped), and unlubricated and lubricated thin-film magnetic rigid disks (as-polished and standard textured). Nanoindentation studies showed that the hardness of the tapes through the magnetic coating is not uniform. These results are consistent with the fact that the tape surface is a composite and is not homogeneous. Nanoscratch experiments performed on magnetic tapes using silicon nitride tips revealed that deformation and displacement of tape surface material occurred after one pass under light loads (~ 100 nN). A comparison between friction force profiles and the corresponding surface roughness profiles of all samples tested shows a poor correlation between localized values of friction and surface roughness. Detailed studies of friction and surface profiles demonstrate an excellent correlation between localized variation of the slope of the surface roughness along the sliding direction and the localized variation of friction. Micro-scale friction in magnetic media and natural diamond appears to be due to adhesive and ratchet (roughness) mechanisms. Directionality in the local variation of micro-scale friction data was observed as the samples were scanned in either direction, resulting from the scanning direction and the anisotropy in the surface topography. Micro-scale coefficient of friction is generally found to be smaller than the macro coefficient of friction as there may be less ploughing contribution in micro-scale measurements.

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Roughness measurements of nonlinear optical polymer films by scanning tunneling microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100152082 ◽

1989 ◽

Vol 47 ◽

pp. 22-23

Author(s):

I. H. Musselman ◽

R.-T. Chen ◽

P. E. Russell

Keyword(s):

Surface Roughness ◽

Scanning Tunneling Microscopy ◽

Nonlinear Optical ◽

Polymer Surface ◽

Light Extinction ◽

Scanning Tunneling ◽

Silicon Substrates ◽

Tunneling Microscopy ◽

Optical Polymer ◽

Total Light

Scanning tunneling microscopy (STM) has been used to characterize the surface roughness of nonlinear optical (NLO) polymers. A review of STM of polymer surfaces is included in this volume. The NLO polymers are instrumental in the development of electrooptical waveguide devices, the most fundamental of which is the modulator. The most common modulator design is the Mach Zehnder interferometer, in which the input light is split into two legs and then recombined into a common output within the two dimensional waveguide. A π phase retardation, resulting in total light extinction at the output of the interferometer, can be achieved by changing the refractive index of one leg with respect to the other using the electrooptic effect. For best device performance, it is essential that the NLO polymer exhibit minimal surface roughness in order to reduce light scattering. Scanning tunneling microscopy, with its high lateral and vertical resolution, is capable of quantifying the NLO polymer surface roughness induced by processing. Results are presented below in which STM was used to measure the surface roughness of films produced by spin-coating NLO-active polymers onto silicon substrates.

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Surface roughness measurements of vanadium-contaminated fluidized cracking catalysts by atomic force microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100166798 ◽

1996 ◽

Vol 54 ◽

pp. 866-867

Author(s):

H. Kinney ◽

M.L. Occelli ◽

S.A.C. Gould

Keyword(s):

Surface Roughness ◽

Zeolite Y ◽

Atomic Level ◽

Microporous Structure ◽

Contact Mode ◽

Force Microscopy ◽

Atomic Force ◽

Before And After ◽

Roughness Measurements ◽

Cracking Catalysts

For this study we have used a contact mode atomic force microscope (AFM) to study to topography of fluidized cracking catalysts (FCC), before and after contamination with 5% vanadium. We selected the AFM because of its ability to well characterize the surface roughness of materials down to the atomic level. It is believed that the cracking in the FCCs occurs mainly on the catalysts top 10-15 μm suggesting that the surface corrugation could play a key role in the FCCs microactivity properties. To test this hypothesis, we chose vanadium as a contaminate because this metal is capable of irreversibly destroying the FCC crystallinity as well as it microporous structure. In addition, we wanted to examine the extent to which steaming affects the vanadium contaminated FCC. Using the AFM, we measured the surface roughness of FCCs, before and after contamination and after steaming.We obtained our FCC (GRZ-1) from Davison. The FCC is generated so that it contains and estimated 35% rare earth exchaged zeolite Y, 50% kaolin and 15% binder.

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