Abstract
A model for the lateral contact stiffness for an elastic foundation was developed. The model was evaluated using a low force and low contact pressure microtribometer capable of performing indentation and reciprocated sliding experiments. The slope of lateral force versus the lateral displacement was used to fit the shear modulus. When complementary elastic indentation measurements are made to determine the composite modulus of the elastic foundation, there is sufficient data to fit elastic modulus, shear modulus, and Poisson ratio for these thin films. Using these models, the elastic properties for a thin (~65 μm) vertically aligned multiwall carbon nanotube film were evaluated. The experiments were performed with a silicon nitride indenter (radius = 1.6 mm) over a range in loads from 100 to 800 μN. The resulting values of the elastic modulus, shear modulus, and Poisson ratio were E = 429 kPa, G = 156 kPa, and ν = 0.37, respectively.
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Abbreviations
- A c :
-
Contact area
- b :
-
Contact radius
- C :
-
Resistance to deformation
- d :
-
Indentation depth
- Δx :
-
Lateral deformation
- E :
-
Elastic modulus
- E′:
-
Composite elastic modulus
- F f :
-
Friction force
- F n :
-
Normal force
- G :
-
Shear modulus
- k c :
-
Lateral contact stiffness
- ν :
-
Poisson’s ratio
- R :
-
Indenter radius
- t :
-
Thickness
References
Carpick, R.W., Salmeron, M.: Scratching the surface: fundamental investigations of tribology with atomic force microscopy. Chem. Rev. 97, 1163–1194 (1997)
Carpick, R.W., Ogletree, D.F., Salmeron, M.: A general equation for fitting contact area and friction vs load measurements. J. Colloid Interface Sci. 211, 395–400 (1999)
Carpick, R.W., Ogletree, D.F., Salmeron, M.: Lateral stiffness: a new nanomechanical measurement for the determination of shear strengths with friction force microscopy. Appl. Phys. Lett. 70, 1548–1550 (1997)
Luan, B.Q., Robbins, M.O.: The breakdown of continuum models for mechanical contacts. Nature 435, 929–932 (2005)
Xiao, X.D., Hu, J., Charych, D.H., Salmeron, M.: Chain length dependence of the frictional properties of alkylsilane molecules self-assembled on mica studied by atomic force microscopy. Langmuir 12, 235–237 (1996)
Burris, D.L., Boesl, B., Bourne, G.R., Sawyer, W.G.: Polymeric nanocomposites for tribological applications. Macromol. Mater. Eng. 292, 387–402 (2007)
Jang, I., Burris, D.L., Dickrell, P.L., Barry, P.R., Santos, C., Perry, S.S., Phillpot, S.R., Sinnott, S.B., Sawyer, W.G.: Sliding orientation effects on the tribological properties of polytetrafluoroethylene. J. Appl. Phys. 102, Article No. 123509 (2007)
Sawyer, W.G., Wahl, K.J.: Accessing inaccessible interfaces: In situ approaches to materials tribology. MRS Bull. 33, 1145–1148 (2008)
Wahl, K.J., Sawyer, W.G.: Observing interfacial sliding processes in solid-solid contacts. MRS Bull. 33, 1159–1167 (2008)
Reedy, E.D.: Contact mechanics for coated spheres that includes the transition from weak to strong adhesion. J. Mater. Res. 22, 2617–2622 (2007)
Reedy, E.D.: Thin-coating contact mechanics with adhesion. J. Mater. Res. 21, 2660–2668 (2006)
Rennie, A.C., Dickrell, P.L., Sawyer, W.G.: Friction coefficient of soft contact lenses: measurements and modeling. Tribol. Lett. 18, 499–504 (2005)
Hill, I.J., Sawyer, W.G.: Energy, adhesion, and the elastic foundation. Tribol. Lett. 453–461 (2010)
Delrio, F.W., De Boer, M.P., Knapp, J.A., Reedy, E.D., Clews, P.J., Dunn, M.L.: The role of van der Waals forces in adhesion of micromachined surfaces. Nat. Mater. 4, 629–634 (2005)
Johnson, K.L., Sridhar, I.: Adhesion between a spherical indenter and an elastic solid with a compliant elastic coating. J. Phys. D. Appl. Phys. 34, 683–689 (2001)
McGuiggan, P.M., Wallace, J.S., Smith, D.T., Sridhar, I., Zheng, Z.W., Johnson, K.L.: Contact mechanics of layered elastic materials: experiment and theory. J. Phys. D. Appl. Phys. 40, 5984–5994 (2007)
Sridhar, I., Zheng, Z.W., Johnson, K.L.: A detailed analysis of adhesion mechanics between a compliant elastic coating and a spherical probe. J. Phys. D. Appl. Phys. 37, 2886–2895 (2004)
Cao, A.Y., Dickrell, P.L., Sawyer, W.G., Ghasemi-Nejhad, M.N., Ajayan, P.M.: Super-compressible foamlike carbon nanotube films. Science 310, 1307–1310 (2005)
Bult, J.B., Sawyer, W.G., Ajayan, P.M., Schadler, L.S.: Passivation oxide controlled selective carbon nanotube growth on metal substrates. Nanotechnology 20, Article No. 085302 (2009)
Dickrell, P.L., Pal, S.K., Bourne, G.R., Muratore, C., Voevodin, A.A., Ajayan, P.M., Schadler, L.S., Sawyer, W.G.: Tunable friction behavior of oriented carbon nanotube films. Tribol. Lett. 24, 85–90 (2006)
Dickrell, P.L., Sinnott, S.B., Hahn, D.W., Raravikar, N.R., Schadler, L.S., Ajayan, P.M., Sawyer, W.G.: Frictional anisotropy of oriented carbon nanotube surfaces. Tribol. Lett. 18, 59–62 (2005)
Toth, G., Maklin, J., Halonen, N., Palosaari, J., Juuti, J., Jantunen, H., Kordas, K., Sawyer, W.G., Vajtai, R., Ajayan, P.M.: Carbon-nanotube-based electrical brush contacts. Adv. Mater. 21, 2054–2058 (2009)
Acknowledgments
Financial support for this study was provided through an AFOSR-MURI Grant FA9550-04-1-0367. We are also indebted to Profs. Linda Schadler and P. M. Ajayan and the Rensselaer Nanotechnology Center for many helpful discussions regarding MWNT films and for providing numerous samples to our laboratory over the years.
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Dickrell, D.J., Sawyer, W.G. Lateral Contact Stiffness and the Elastic Foundation. Tribol Lett 41, 17–21 (2011). https://doi.org/10.1007/s11249-010-9666-5
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DOI: https://doi.org/10.1007/s11249-010-9666-5